| Total Complexity | 75 |
| Total Lines | 845 |
| Duplicated Lines | 0 % |
| Changes | 0 | ||
Complex classes like Database often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Database, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 19 | abstract class Database |
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| 20 | { |
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| 21 | |||
| 22 | /** |
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| 23 | * Database connector object |
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| 24 | * |
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| 25 | * @var DBConnector |
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| 26 | */ |
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| 27 | protected $connector = null; |
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| 28 | |||
| 29 | /** |
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| 30 | * In cases where your environment does not have 'SHOW DATABASES' permission, |
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| 31 | * you can set this to true. Then selectDatabase() will always connect without |
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| 32 | * doing databaseExists() check. |
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| 33 | * |
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| 34 | * @var bool |
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| 35 | */ |
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| 36 | private static $optimistic_connect = false; |
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| 37 | |||
| 38 | /** |
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| 39 | * Amount of queries executed, for debugging purposes. |
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| 40 | * |
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| 41 | * @var int |
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| 42 | */ |
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| 43 | protected $queryCount = 0; |
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| 44 | |||
| 45 | /** |
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| 46 | * Get the current connector |
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| 47 | * |
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| 48 | * @return DBConnector |
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| 49 | */ |
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| 50 | public function getConnector() |
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| 51 | { |
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| 52 | return $this->connector; |
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| 53 | } |
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| 54 | |||
| 55 | /** |
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| 56 | * Injector injection point for connector dependency |
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| 57 | * |
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| 58 | * @param DBConnector $connector |
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| 59 | */ |
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| 60 | public function setConnector(DBConnector $connector) |
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| 61 | { |
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| 62 | $this->connector = $connector; |
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| 63 | } |
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| 64 | |||
| 65 | /** |
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| 66 | * Database schema manager object |
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| 67 | * |
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| 68 | * @var DBSchemaManager |
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| 69 | */ |
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| 70 | protected $schemaManager = null; |
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| 71 | |||
| 72 | /** |
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| 73 | * Returns the current schema manager |
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| 74 | * |
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| 75 | * @return DBSchemaManager |
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| 76 | */ |
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| 77 | public function getSchemaManager() |
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| 80 | } |
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| 81 | |||
| 82 | /** |
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| 83 | * Injector injection point for schema manager |
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| 84 | * |
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| 85 | * @param DBSchemaManager $schemaManager |
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| 86 | */ |
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| 87 | public function setSchemaManager(DBSchemaManager $schemaManager) |
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| 88 | { |
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| 89 | $this->schemaManager = $schemaManager; |
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| 90 | |||
| 91 | if ($this->schemaManager) { |
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| 92 | $this->schemaManager->setDatabase($this); |
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| 93 | } |
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| 94 | } |
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| 95 | |||
| 96 | /** |
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| 97 | * Query builder object |
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| 98 | * |
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| 99 | * @var DBQueryBuilder |
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| 100 | */ |
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| 101 | protected $queryBuilder = null; |
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| 102 | |||
| 103 | /** |
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| 104 | * Returns the current query builder |
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| 105 | * |
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| 106 | * @return DBQueryBuilder |
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| 107 | */ |
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| 108 | public function getQueryBuilder() |
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| 109 | { |
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| 110 | return $this->queryBuilder; |
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| 111 | } |
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| 112 | |||
| 113 | /** |
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| 114 | * Injector injection point for schema manager |
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| 115 | * |
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| 116 | * @param DBQueryBuilder $queryBuilder |
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| 117 | */ |
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| 118 | public function setQueryBuilder(DBQueryBuilder $queryBuilder) |
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| 119 | { |
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| 120 | $this->queryBuilder = $queryBuilder; |
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| 121 | } |
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| 122 | |||
| 123 | /** |
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| 124 | * Execute the given SQL query. |
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| 125 | * |
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| 126 | * @param string $sql The SQL query to execute |
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| 127 | * @param int $errorLevel The level of error reporting to enable for the query |
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| 128 | * @return Query |
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| 129 | */ |
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| 130 | public function query($sql, $errorLevel = E_USER_ERROR) |
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| 131 | { |
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| 132 | // Check if we should only preview this query |
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| 133 | if ($this->previewWrite($sql)) { |
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| 134 | return null; |
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| 135 | } |
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| 136 | |||
| 137 | // Benchmark query |
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| 138 | $connector = $this->connector; |
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| 139 | return $this->benchmarkQuery( |
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| 140 | $sql, |
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| 141 | function ($sql) use ($connector, $errorLevel) { |
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| 142 | return $connector->query($sql, $errorLevel); |
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| 143 | } |
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| 144 | ); |
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| 145 | } |
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| 146 | |||
| 147 | |||
| 148 | /** |
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| 149 | * Execute the given SQL parameterised query with the specified arguments |
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| 150 | * |
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| 151 | * @param string $sql The SQL query to execute. The ? character will denote parameters. |
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| 152 | * @param array $parameters An ordered list of arguments. |
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| 153 | * @param int $errorLevel The level of error reporting to enable for the query |
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| 154 | * @return Query |
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| 155 | */ |
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| 156 | public function preparedQuery($sql, $parameters, $errorLevel = E_USER_ERROR) |
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| 157 | { |
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| 158 | // Check if we should only preview this query |
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| 159 | if ($this->previewWrite($sql)) { |
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| 160 | return null; |
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| 161 | } |
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| 162 | |||
| 163 | // Benchmark query |
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| 164 | $connector = $this->connector; |
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| 165 | return $this->benchmarkQuery( |
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| 166 | $sql, |
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| 167 | function ($sql) use ($connector, $parameters, $errorLevel) { |
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| 168 | return $connector->preparedQuery($sql, $parameters, $errorLevel); |
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| 169 | }, |
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| 170 | $parameters |
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| 171 | ); |
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| 172 | } |
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| 173 | |||
| 174 | /** |
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| 175 | * Determines if the query should be previewed, and thus interrupted silently. |
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| 176 | * If so, this function also displays the query via the debuging system. |
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| 177 | * Subclasess should respect the results of this call for each query, and not |
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| 178 | * execute any queries that generate a true response. |
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| 179 | * |
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| 180 | * @param string $sql The query to be executed |
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| 181 | * @return boolean Flag indicating that the query was previewed |
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| 182 | */ |
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| 183 | protected function previewWrite($sql) |
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| 184 | { |
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| 185 | // Only preview if previewWrite is set, we are in dev mode, and |
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| 186 | // the query is mutable |
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| 187 | if (isset($_REQUEST['previewwrite']) |
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| 188 | && Director::isDev() |
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| 189 | && $this->connector->isQueryMutable($sql) |
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| 190 | ) { |
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| 191 | // output preview message |
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| 192 | Debug::message("Will execute: $sql"); |
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| 193 | return true; |
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| 194 | } else { |
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| 195 | return false; |
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| 196 | } |
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| 197 | } |
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| 198 | |||
| 199 | /** |
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| 200 | * Allows the display and benchmarking of queries as they are being run |
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| 201 | * |
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| 202 | * @param string $sql Query to run, and single parameter to callback |
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| 203 | * @param callable $callback Callback to execute code |
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| 204 | * @param array $parameters Parameters for any parameterised query |
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| 205 | * @return mixed Result of query |
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| 206 | */ |
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| 207 | protected function benchmarkQuery($sql, $callback, $parameters = array()) |
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| 208 | { |
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| 209 | if (isset($_REQUEST['showqueries']) && Director::isDev()) { |
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| 210 | $this->queryCount++; |
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| 211 | $starttime = microtime(true); |
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| 212 | $result = $callback($sql); |
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| 213 | $endtime = round(microtime(true) - $starttime, 4); |
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| 214 | // replace parameters as closely as possible to what we'd expect the DB to put in |
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| 215 | if (strtolower($_REQUEST['showqueries']) == 'inline') { |
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| 216 | $sql = DB::inline_parameters($sql, $parameters); |
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| 217 | } |
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| 218 | $queryCount = sprintf("%04d", $this->queryCount); |
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| 219 | Debug::message("\n$queryCount: $sql\n{$endtime}s\n", false); |
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| 220 | return $result; |
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| 221 | } else { |
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| 222 | return $callback($sql); |
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| 223 | } |
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| 224 | } |
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| 225 | |||
| 226 | /** |
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| 227 | * Get the autogenerated ID from the previous INSERT query. |
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| 228 | * |
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| 229 | * @param string $table The name of the table to get the generated ID for |
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| 230 | * @return integer the most recently generated ID for the specified table |
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| 231 | */ |
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| 232 | public function getGeneratedID($table) |
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| 233 | { |
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| 234 | return $this->connector->getGeneratedID($table); |
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| 235 | } |
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| 236 | |||
| 237 | /** |
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| 238 | * Determines if we are connected to a server AND have a valid database |
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| 239 | * selected. |
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| 240 | * |
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| 241 | * @return boolean Flag indicating that a valid database is connected |
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| 242 | */ |
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| 243 | public function isActive() |
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| 244 | { |
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| 245 | return $this->connector->isActive(); |
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| 246 | } |
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| 247 | |||
| 248 | /** |
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| 249 | * Returns an escaped string. This string won't be quoted, so would be suitable |
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| 250 | * for appending to other quoted strings. |
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| 251 | * |
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| 252 | * @param mixed $value Value to be prepared for database query |
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| 253 | * @return string Prepared string |
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| 254 | */ |
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| 255 | public function escapeString($value) |
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| 256 | { |
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| 257 | return $this->connector->escapeString($value); |
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| 258 | } |
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| 259 | |||
| 260 | /** |
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| 261 | * Wrap a string into DB-specific quotes. |
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| 262 | * |
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| 263 | * @param mixed $value Value to be prepared for database query |
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| 264 | * @return string Prepared string |
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| 265 | */ |
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| 266 | public function quoteString($value) |
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| 267 | { |
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| 268 | return $this->connector->quoteString($value); |
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| 269 | } |
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| 270 | |||
| 271 | /** |
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| 272 | * Escapes an identifier (table / database name). Typically the value |
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| 273 | * is simply double quoted. Don't pass in already escaped identifiers in, |
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| 274 | * as this will double escape the value! |
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| 275 | * |
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| 276 | * @param string|array $value The identifier to escape or list of split components |
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| 277 | * @param string $separator Splitter for each component |
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| 278 | * @return string |
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| 279 | */ |
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| 280 | public function escapeIdentifier($value, $separator = '.') |
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| 281 | { |
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| 282 | // Split string into components |
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| 283 | if (!is_array($value)) { |
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| 284 | $value = explode($separator, $value); |
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| 285 | } |
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| 286 | |||
| 287 | // Implode quoted column |
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| 288 | return '"' . implode('"' . $separator . '"', $value) . '"'; |
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| 289 | } |
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| 290 | |||
| 291 | /** |
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| 292 | * Escapes unquoted columns keys in an associative array |
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| 293 | * |
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| 294 | * @param array $fieldValues |
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| 295 | * @return array List of field values with the keys as escaped column names |
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| 296 | */ |
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| 297 | protected function escapeColumnKeys($fieldValues) |
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| 298 | { |
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| 299 | $out = array(); |
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| 300 | foreach ($fieldValues as $field => $value) { |
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| 301 | $out[$this->escapeIdentifier($field)] = $value; |
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| 302 | } |
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| 303 | return $out; |
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| 304 | } |
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| 305 | |||
| 306 | /** |
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| 307 | * Execute a complex manipulation on the database. |
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| 308 | * A manipulation is an array of insert / or update sequences. The keys of the array are table names, |
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| 309 | * and the values are map containing 'command' and 'fields'. Command should be 'insert' or 'update', |
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| 310 | * and fields should be a map of field names to field values, NOT including quotes. |
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| 311 | * |
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| 312 | * The field values could also be in paramaterised format, such as |
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| 313 | * array('MAX(?,?)' => array(42, 69)), allowing the use of raw SQL values such as |
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| 314 | * array('NOW()' => array()). |
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| 315 | * |
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| 316 | * @see SQLWriteExpression::addAssignments for syntax examples |
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| 317 | * |
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| 318 | * @param array $manipulation |
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| 319 | */ |
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| 320 | public function manipulate($manipulation) |
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| 321 | { |
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| 322 | if (empty($manipulation)) { |
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| 323 | return; |
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| 324 | } |
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| 325 | |||
| 326 | foreach ($manipulation as $table => $writeInfo) { |
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| 327 | if (empty($writeInfo['fields'])) { |
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| 328 | continue; |
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| 329 | } |
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| 330 | // Note: keys of $fieldValues are not escaped |
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| 331 | $fieldValues = $writeInfo['fields']; |
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| 332 | |||
| 333 | // Switch command type |
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| 334 | switch ($writeInfo['command']) { |
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| 335 | case "update": |
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| 336 | // Build update |
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| 337 | $query = new SQLUpdate("\"$table\"", $this->escapeColumnKeys($fieldValues)); |
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| 338 | |||
| 339 | // Set best condition to use |
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| 340 | if (!empty($writeInfo['where'])) { |
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| 341 | $query->addWhere($writeInfo['where']); |
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| 342 | } elseif (!empty($writeInfo['id'])) { |
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| 343 | $query->addWhere(array('"ID"' => $writeInfo['id'])); |
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| 344 | } |
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| 345 | |||
| 346 | // Test to see if this update query shouldn't, in fact, be an insert |
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| 347 | if ($query->toSelect()->count()) { |
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| 348 | $query->execute(); |
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| 349 | break; |
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| 350 | } |
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| 351 | // ...if not, we'll skip on to the insert code |
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| 352 | |||
| 353 | case "insert": |
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| 354 | // Ensure that the ID clause is given if possible |
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| 355 | if (!isset($fieldValues['ID']) && isset($writeInfo['id'])) { |
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| 356 | $fieldValues['ID'] = $writeInfo['id']; |
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| 357 | } |
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| 358 | |||
| 359 | // Build insert |
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| 360 | $query = new SQLInsert("\"$table\"", $this->escapeColumnKeys($fieldValues)); |
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| 361 | |||
| 362 | $query->execute(); |
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| 363 | break; |
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| 364 | |||
| 365 | default: |
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| 366 | user_error( |
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| 367 | "SS_Database::manipulate() Can't recognise command '{$writeInfo['command']}'", |
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| 368 | E_USER_ERROR |
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| 369 | ); |
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| 370 | } |
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| 371 | } |
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| 372 | } |
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| 373 | |||
| 374 | /** |
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| 375 | * Enable supression of database messages. |
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| 376 | */ |
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| 377 | public function quiet() |
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| 378 | { |
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| 379 | $this->schemaManager->quiet(); |
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| 380 | } |
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| 381 | |||
| 382 | /** |
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| 383 | * Clear all data out of the database |
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| 384 | */ |
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| 385 | public function clearAllData() |
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| 390 | } |
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| 391 | } |
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| 392 | |||
| 393 | /** |
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| 394 | * Clear all data in a given table |
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| 395 | * |
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| 396 | * @param string $table Name of table |
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| 397 | */ |
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| 398 | public function clearTable($table) |
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| 399 | { |
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| 400 | $this->query("TRUNCATE \"$table\""); |
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| 401 | } |
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| 402 | |||
| 403 | /** |
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| 404 | * Generates a WHERE clause for null comparison check |
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| 405 | * |
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| 406 | * @param string $field Quoted field name |
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| 407 | * @param bool $isNull Whether to check for NULL or NOT NULL |
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| 408 | * @return string Non-parameterised null comparison clause |
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| 409 | */ |
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| 410 | public function nullCheckClause($field, $isNull) |
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| 411 | { |
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| 412 | $clause = $isNull |
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| 413 | ? "%s IS NULL" |
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| 414 | : "%s IS NOT NULL"; |
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| 415 | return sprintf($clause, $field); |
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| 416 | } |
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| 417 | |||
| 418 | /** |
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| 419 | * Generate a WHERE clause for text matching. |
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| 420 | * |
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| 421 | * @param String $field Quoted field name |
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| 422 | * @param String $value Escaped search. Can include percentage wildcards. |
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| 423 | * Ignored if $parameterised is true. |
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| 424 | * @param boolean $exact Exact matches or wildcard support. |
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| 425 | * @param boolean $negate Negate the clause. |
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| 426 | * @param boolean $caseSensitive Enforce case sensitivity if TRUE or FALSE. |
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| 427 | * Fallback to default collation if set to NULL. |
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| 428 | * @param boolean $parameterised Insert the ? placeholder rather than the |
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| 429 | * given value. If this is true then $value is ignored. |
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| 430 | * @return String SQL |
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| 431 | */ |
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| 432 | abstract public function comparisonClause( |
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| 433 | $field, |
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| 434 | $value, |
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| 435 | $exact = false, |
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| 436 | $negate = false, |
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| 437 | $caseSensitive = null, |
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| 438 | $parameterised = false |
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| 439 | ); |
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| 440 | |||
| 441 | /** |
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| 442 | * function to return an SQL datetime expression that can be used with the adapter in use |
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| 443 | * used for querying a datetime in a certain format |
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| 444 | * |
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| 445 | * @param string $date to be formated, can be either 'now', literal datetime like '1973-10-14 10:30:00' or |
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| 446 | * field name, e.g. '"SiteTree"."Created"' |
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| 447 | * @param string $format to be used, supported specifiers: |
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| 448 | * %Y = Year (four digits) |
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| 449 | * %m = Month (01..12) |
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| 450 | * %d = Day (01..31) |
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| 451 | * %H = Hour (00..23) |
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| 452 | * %i = Minutes (00..59) |
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| 453 | * %s = Seconds (00..59) |
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| 454 | * %U = unix timestamp, can only be used on it's own |
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| 455 | * @return string SQL datetime expression to query for a formatted datetime |
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| 456 | */ |
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| 457 | abstract public function formattedDatetimeClause($date, $format); |
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| 458 | |||
| 459 | /** |
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| 460 | * function to return an SQL datetime expression that can be used with the adapter in use |
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| 461 | * used for querying a datetime addition |
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| 462 | * |
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| 463 | * @param string $date, can be either 'now', literal datetime like '1973-10-14 10:30:00' or field name, |
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| 464 | * e.g. '"SiteTree"."Created"' |
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| 465 | * @param string $interval to be added, use the format [sign][integer] [qualifier], e.g. -1 Day, +15 minutes, |
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| 466 | * +1 YEAR |
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| 467 | * supported qualifiers: |
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| 468 | * - years |
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| 469 | * - months |
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| 470 | * - days |
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| 471 | * - hours |
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| 472 | * - minutes |
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| 473 | * - seconds |
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| 474 | * This includes the singular forms as well |
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| 475 | * @return string SQL datetime expression to query for a datetime (YYYY-MM-DD hh:mm:ss) which is the result of |
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| 476 | * the addition |
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| 477 | */ |
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| 478 | abstract public function datetimeIntervalClause($date, $interval); |
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| 479 | |||
| 480 | /** |
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| 481 | * function to return an SQL datetime expression that can be used with the adapter in use |
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| 482 | * used for querying a datetime substraction |
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| 483 | * |
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| 484 | * @param string $date1, can be either 'now', literal datetime like '1973-10-14 10:30:00' or field name |
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| 485 | * e.g. '"SiteTree"."Created"' |
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| 486 | * @param string $date2 to be substracted of $date1, can be either 'now', literal datetime |
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| 487 | * like '1973-10-14 10:30:00' or field name, e.g. '"SiteTree"."Created"' |
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| 488 | * @return string SQL datetime expression to query for the interval between $date1 and $date2 in seconds which |
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| 489 | * is the result of the substraction |
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| 490 | */ |
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| 491 | abstract public function datetimeDifferenceClause($date1, $date2); |
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| 492 | |||
| 493 | /** |
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| 494 | * String operator for concatenation of strings |
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| 495 | * |
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| 496 | * @return string |
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| 497 | */ |
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| 498 | public function concatOperator() |
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| 499 | { |
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| 500 | // @todo Make ' + ' in mssql |
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| 501 | return ' || '; |
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| 502 | } |
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| 503 | |||
| 504 | /** |
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| 505 | * Returns true if this database supports collations |
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| 506 | * |
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| 507 | * @return boolean |
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| 508 | */ |
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| 509 | abstract public function supportsCollations(); |
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| 510 | |||
| 511 | /** |
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| 512 | * Can the database override timezone as a connection setting, |
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| 513 | * or does it use the system timezone exclusively? |
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| 514 | * |
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| 515 | * @return Boolean |
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| 516 | */ |
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| 517 | abstract public function supportsTimezoneOverride(); |
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| 518 | |||
| 519 | /** |
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| 520 | * Query for the version of the currently connected database |
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| 521 | * @return string Version of this database |
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| 522 | */ |
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| 523 | public function getVersion() |
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| 526 | } |
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| 527 | |||
| 528 | /** |
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| 529 | * Get the database server type (e.g. mysql, postgresql). |
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| 530 | * This value is passed to the connector as the 'driver' argument when |
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| 531 | * initiating a database connection |
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| 532 | * |
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| 533 | * @return string |
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| 534 | */ |
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| 535 | abstract public function getDatabaseServer(); |
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| 536 | |||
| 537 | /** |
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| 538 | * Return the number of rows affected by the previous operation. |
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| 539 | * @return int |
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| 540 | */ |
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| 541 | public function affectedRows() |
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| 542 | { |
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| 543 | return $this->connector->affectedRows(); |
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| 544 | } |
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| 545 | |||
| 546 | /** |
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| 547 | * The core search engine, used by this class and its subclasses to do fun stuff. |
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| 548 | * Searches both SiteTree and File. |
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| 549 | * |
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| 550 | * @param array $classesToSearch List of classes to search |
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| 551 | * @param string $keywords Keywords as a string. |
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| 552 | * @param integer $start Item to start returning results from |
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| 553 | * @param integer $pageLength Number of items per page |
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| 554 | * @param string $sortBy Sort order expression |
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| 555 | * @param string $extraFilter Additional filter |
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| 556 | * @param boolean $booleanSearch Flag for boolean search mode |
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| 557 | * @param string $alternativeFileFilter |
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| 558 | * @param boolean $invertedMatch |
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| 559 | * @return PaginatedList Search results |
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| 560 | */ |
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| 561 | abstract public function searchEngine( |
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| 562 | $classesToSearch, |
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| 563 | $keywords, |
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| 564 | $start, |
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| 565 | $pageLength, |
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| 566 | $sortBy = "Relevance DESC", |
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| 567 | $extraFilter = "", |
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| 568 | $booleanSearch = false, |
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| 569 | $alternativeFileFilter = "", |
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| 570 | $invertedMatch = false |
||
| 571 | ); |
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| 572 | |||
| 573 | /** |
||
| 574 | * Determines if this database supports transactions |
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| 575 | * |
||
| 576 | * @return boolean Flag indicating support for transactions |
||
| 577 | */ |
||
| 578 | abstract public function supportsTransactions(); |
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| 579 | |||
| 580 | /** |
||
| 581 | * Invoke $callback within a transaction |
||
| 582 | * |
||
| 583 | * @param callable $callback Callback to run |
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| 584 | * @param callable $errorCallback Optional callback to run after rolling back transaction. |
||
| 585 | * @param bool|string $transactionMode Optional transaction mode to use |
||
| 586 | * @param bool $errorIfTransactionsUnsupported If true, this method will fail if transactions are unsupported. |
||
| 587 | * Otherwise, the $callback will potentially be invoked outside of a transaction. |
||
| 588 | * @throws Exception |
||
| 589 | */ |
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| 590 | public function withTransaction( |
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| 616 | } |
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| 617 | } |
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| 618 | |||
| 619 | /* |
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| 620 | * Determines if the current database connection supports a given list of extensions |
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| 621 | * |
||
| 622 | * @param array $extensions List of extensions to check for support of. The key of this array |
||
| 623 | * will be an extension name, and the value the configuration for that extension. This |
||
| 624 | * could be one of partitions, tablespaces, or clustering |
||
| 625 | * @return boolean Flag indicating support for all of the above |
||
| 626 | * @todo Write test cases |
||
| 627 | */ |
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| 628 | public function supportsExtensions($extensions) |
||
| 631 | } |
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| 632 | |||
| 633 | /** |
||
| 634 | * Start a prepared transaction |
||
| 635 | * See http://developer.postgresql.org/pgdocs/postgres/sql-set-transaction.html for details on |
||
| 636 | * transaction isolation options |
||
| 637 | * |
||
| 638 | * @param string|boolean $transactionMode Transaction mode, or false to ignore |
||
| 639 | * @param string|boolean $sessionCharacteristics Session characteristics, or false to ignore |
||
| 640 | */ |
||
| 641 | abstract public function transactionStart($transactionMode = false, $sessionCharacteristics = false); |
||
| 642 | |||
| 643 | /** |
||
| 644 | * Create a savepoint that you can jump back to if you encounter problems |
||
| 645 | * |
||
| 646 | * @param string $savepoint Name of savepoint |
||
| 647 | */ |
||
| 648 | abstract public function transactionSavepoint($savepoint); |
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| 649 | |||
| 650 | /** |
||
| 651 | * Rollback or revert to a savepoint if your queries encounter problems |
||
| 652 | * If you encounter a problem at any point during a transaction, you may |
||
| 653 | * need to rollback that particular query, or return to a savepoint |
||
| 654 | * |
||
| 655 | * @param string|boolean $savepoint Name of savepoint, or leave empty to rollback |
||
| 656 | * to last savepoint |
||
| 657 | * @return bool|null Boolean is returned if success state is known, or null if |
||
| 658 | * unknown. Note: For error checking purposes null should not be treated as error. |
||
| 659 | */ |
||
| 660 | abstract public function transactionRollback($savepoint = false); |
||
| 661 | |||
| 662 | /** |
||
| 663 | * Commit everything inside this transaction so far |
||
| 664 | * |
||
| 665 | * @param bool $chain |
||
| 666 | * @return bool|null Boolean is returned if success state is known, or null if |
||
| 667 | * unknown. Note: For error checking purposes null should not be treated as error. |
||
| 668 | */ |
||
| 669 | abstract public function transactionEnd($chain = false); |
||
| 670 | |||
| 671 | /** |
||
| 672 | * Return depth of current transaction |
||
| 673 | * |
||
| 674 | * @return int Nesting level, or 0 if not in a transaction |
||
| 675 | */ |
||
| 676 | public function transactionDepth() |
||
| 677 | { |
||
| 678 | // Placeholder error for transactional DBs that don't expose depth |
||
| 679 | if (!$this->supportsTransactions()) { |
||
| 680 | user_error(get_class($this) . " does not support transactionDepth", E_USER_WARNING); |
||
| 681 | } |
||
| 682 | return 0; |
||
| 683 | } |
||
| 684 | |||
| 685 | /** |
||
| 686 | * Determines if the used database supports application-level locks, |
||
| 687 | * which is different from table- or row-level locking. |
||
| 688 | * See {@link getLock()} for details. |
||
| 689 | * |
||
| 690 | * @return bool Flag indicating that locking is available |
||
| 691 | */ |
||
| 692 | public function supportsLocks() |
||
| 693 | { |
||
| 694 | return false; |
||
| 695 | } |
||
| 696 | |||
| 697 | /** |
||
| 698 | * Returns if the lock is available. |
||
| 699 | * See {@link supportsLocks()} to check if locking is generally supported. |
||
| 700 | * |
||
| 701 | * @param string $name Name of the lock |
||
| 702 | * @return bool |
||
| 703 | */ |
||
| 704 | public function canLock($name) |
||
| 705 | { |
||
| 706 | return false; |
||
| 707 | } |
||
| 708 | |||
| 709 | /** |
||
| 710 | * Sets an application-level lock so that no two processes can run at the same time, |
||
| 711 | * also called a "cooperative advisory lock". |
||
| 712 | * |
||
| 713 | * Return FALSE if acquiring the lock fails; otherwise return TRUE, if lock was acquired successfully. |
||
| 714 | * Lock is automatically released if connection to the database is broken (either normally or abnormally), |
||
| 715 | * making it less prone to deadlocks than session- or file-based locks. |
||
| 716 | * Should be accompanied by a {@link releaseLock()} call after the logic requiring the lock has completed. |
||
| 717 | * Can be called multiple times, in which case locks "stack" (PostgreSQL, SQL Server), |
||
| 718 | * or auto-releases the previous lock (MySQL). |
||
| 719 | * |
||
| 720 | * Note that this might trigger the database to wait for the lock to be released, delaying further execution. |
||
| 721 | * |
||
| 722 | * @param string $name Name of lock |
||
| 723 | * @param integer $timeout Timeout in seconds |
||
| 724 | * @return bool |
||
| 725 | */ |
||
| 726 | public function getLock($name, $timeout = 5) |
||
| 727 | { |
||
| 728 | return false; |
||
| 729 | } |
||
| 730 | |||
| 731 | /** |
||
| 732 | * Remove an application-level lock file to allow another process to run |
||
| 733 | * (if the execution aborts (e.g. due to an error) all locks are automatically released). |
||
| 734 | * |
||
| 735 | * @param string $name Name of the lock |
||
| 736 | * @return bool Flag indicating whether the lock was successfully released |
||
| 737 | */ |
||
| 738 | public function releaseLock($name) |
||
| 739 | { |
||
| 740 | return false; |
||
| 741 | } |
||
| 742 | |||
| 743 | /** |
||
| 744 | * Instruct the database to generate a live connection |
||
| 745 | * |
||
| 746 | * @param array $parameters An map of parameters, which should include: |
||
| 747 | * - server: The server, eg, localhost |
||
| 748 | * - username: The username to log on with |
||
| 749 | * - password: The password to log on with |
||
| 750 | * - database: The database to connect to |
||
| 751 | * - charset: The character set to use. Defaults to utf8 |
||
| 752 | * - timezone: (optional) The timezone offset. For example: +12:00, "Pacific/Auckland", or "SYSTEM" |
||
| 753 | * - driver: (optional) Driver name |
||
| 754 | */ |
||
| 755 | public function connect($parameters) |
||
| 756 | { |
||
| 757 | // Ensure that driver is available (required by PDO) |
||
| 758 | if (empty($parameters['driver'])) { |
||
| 759 | $parameters['driver'] = $this->getDatabaseServer(); |
||
| 760 | } |
||
| 761 | |||
| 762 | // Notify connector of parameters |
||
| 763 | $this->connector->connect($parameters); |
||
| 764 | |||
| 765 | // SS_Database subclass maintains responsibility for selecting database |
||
| 766 | // once connected in order to correctly handle schema queries about |
||
| 767 | // existence of database, error handling at the correct level, etc |
||
| 768 | if (!empty($parameters['database'])) { |
||
| 769 | $this->selectDatabase($parameters['database'], false, false); |
||
| 770 | } |
||
| 771 | } |
||
| 772 | |||
| 773 | /** |
||
| 774 | * Determine if the database with the specified name exists |
||
| 775 | * |
||
| 776 | * @param string $name Name of the database to check for |
||
| 777 | * @return bool Flag indicating whether this database exists |
||
| 778 | */ |
||
| 779 | public function databaseExists($name) |
||
| 782 | } |
||
| 783 | |||
| 784 | /** |
||
| 785 | * Retrieves the list of all databases the user has access to |
||
| 786 | * |
||
| 787 | * @return array List of database names |
||
| 788 | */ |
||
| 789 | public function databaseList() |
||
| 792 | } |
||
| 793 | |||
| 794 | /** |
||
| 795 | * Change the connection to the specified database, optionally creating the |
||
| 796 | * database if it doesn't exist in the current schema. |
||
| 797 | * |
||
| 798 | * @param string $name Name of the database |
||
| 799 | * @param bool $create Flag indicating whether the database should be created |
||
| 800 | * if it doesn't exist. If $create is false and the database doesn't exist |
||
| 801 | * then an error will be raised |
||
| 802 | * @param int|bool $errorLevel The level of error reporting to enable for the query, or false if no error |
||
| 803 | * should be raised |
||
| 804 | * @return bool Flag indicating success |
||
| 805 | */ |
||
| 806 | public function selectDatabase($name, $create = false, $errorLevel = E_USER_ERROR) |
||
| 807 | { |
||
| 808 | // In case our live environment is locked down, we can bypass a SHOW DATABASE check |
||
| 809 | $canConnect = Config::inst()->get(static::class, 'optimistic_connect') |
||
| 810 | || $this->schemaManager->databaseExists($name); |
||
| 811 | if ($canConnect) { |
||
| 812 | return $this->connector->selectDatabase($name); |
||
| 813 | } |
||
| 814 | |||
| 815 | // Check DB creation permisson |
||
| 816 | if (!$create) { |
||
| 817 | if ($errorLevel !== false) { |
||
| 818 | user_error("Attempted to connect to non-existing database \"$name\"", $errorLevel); |
||
| 819 | } |
||
| 820 | // Unselect database |
||
| 821 | $this->connector->unloadDatabase(); |
||
| 822 | return false; |
||
| 823 | } |
||
| 824 | $this->schemaManager->createDatabase($name); |
||
| 825 | return $this->connector->selectDatabase($name); |
||
| 826 | } |
||
| 827 | |||
| 828 | /** |
||
| 829 | * Drop the database that this object is currently connected to. |
||
| 830 | * Use with caution. |
||
| 831 | */ |
||
| 832 | public function dropSelectedDatabase() |
||
| 833 | { |
||
| 834 | $databaseName = $this->connector->getSelectedDatabase(); |
||
| 835 | if ($databaseName) { |
||
| 836 | $this->connector->unloadDatabase(); |
||
| 837 | $this->schemaManager->dropDatabase($databaseName); |
||
| 838 | } |
||
| 839 | } |
||
| 840 | |||
| 841 | /** |
||
| 842 | * Returns the name of the currently selected database |
||
| 843 | * |
||
| 844 | * @return string|null Name of the selected database, or null if none selected |
||
| 845 | */ |
||
| 846 | public function getSelectedDatabase() |
||
| 849 | } |
||
| 850 | |||
| 851 | /** |
||
| 852 | * Return SQL expression used to represent the current date/time |
||
| 853 | * |
||
| 854 | * @return string Expression for the current date/time |
||
| 855 | */ |
||
| 856 | abstract public function now(); |
||
| 857 | |||
| 858 | /** |
||
| 859 | * Returns the database-specific version of the random() function |
||
| 860 | * |
||
| 861 | * @return string Expression for a random value |
||
| 862 | */ |
||
| 863 | abstract public function random(); |
||
| 864 | } |
||
| 865 |