Complex classes like AbstractQuery 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. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
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 AbstractQuery, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 22 | abstract class AbstractQuery |
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| 23 | { |
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| 24 | /** |
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| 25 | * |
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| 26 | * Data to be bound to the query. |
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| 27 | * |
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| 28 | * @var array |
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| 29 | * |
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| 30 | */ |
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| 31 | protected $bind_values = array(); |
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| 32 | |||
| 33 | /** |
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| 34 | * |
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| 35 | * The list of WHERE conditions. |
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| 36 | * |
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| 37 | * @var array |
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| 38 | * |
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| 39 | */ |
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| 40 | protected $where = array(); |
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| 41 | |||
| 42 | /** |
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| 43 | * |
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| 44 | * ORDER BY these columns. |
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| 45 | * |
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| 46 | * @var array |
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| 47 | * |
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| 48 | */ |
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| 49 | protected $order_by = array(); |
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| 50 | |||
| 51 | /** |
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| 52 | * |
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| 53 | * The number of rows to select |
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| 54 | * |
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| 55 | * @var int |
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| 56 | * |
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| 57 | */ |
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| 58 | protected $limit = 0; |
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| 59 | |||
| 60 | /** |
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| 61 | * |
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| 62 | * Return rows after this offset. |
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| 63 | * |
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| 64 | * @var int |
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| 65 | * |
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| 66 | */ |
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| 67 | protected $offset = 0; |
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| 68 | |||
| 69 | /** |
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| 70 | * |
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| 71 | * The list of flags. |
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| 72 | * |
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| 73 | * @var array |
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| 74 | * |
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| 75 | */ |
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| 76 | protected $flags = array(); |
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| 77 | |||
| 78 | /** |
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| 79 | * |
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| 80 | * A helper for quoting identifier names. |
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| 81 | * |
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| 82 | * @var Quoter |
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| 83 | * |
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| 84 | */ |
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| 85 | protected $quoter; |
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| 86 | |||
| 87 | /** |
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| 88 | * |
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| 89 | * Prefix to use on placeholders for "sequential" bound values; used for |
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| 90 | * deconfliction when merging bound values from sub-selects, etc. |
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| 91 | * |
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| 92 | * @var mixed |
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| 93 | * |
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| 94 | */ |
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| 95 | protected $seq_bind_prefix = ''; |
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| 96 | |||
| 97 | /** |
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| 98 | * |
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| 99 | * Constructor. |
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| 100 | * |
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| 101 | * @param Quoter $quoter A helper for quoting identifier names. |
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| 102 | * |
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| 103 | * @param string $seq_bind_prefix A prefix for rewritten sequential-binding |
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| 104 | * placeholders (@see getSeqPlaceholder()). |
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| 105 | * |
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| 106 | */ |
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| 107 | 397 | public function __construct(Quoter $quoter, $seq_bind_prefix = '') |
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| 108 | { |
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| 109 | 397 | $this->quoter = $quoter; |
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| 110 | 397 | $this->seq_bind_prefix = $seq_bind_prefix; |
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| 111 | 397 | } |
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| 112 | |||
| 113 | /** |
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| 114 | * |
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| 115 | * Returns the prefix for rewritten sequential-binding placeholders |
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| 116 | * (@see getSeqPlaceholder()). |
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| 117 | * |
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| 118 | * @return string |
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| 119 | * |
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| 120 | */ |
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| 121 | 1 | public function getSeqBindPrefix() |
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| 122 | { |
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| 123 | 1 | return $this->seq_bind_prefix; |
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| 124 | } |
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| 125 | |||
| 126 | /** |
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| 127 | * |
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| 128 | * Returns this query object as an SQL statement string. |
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| 129 | * |
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| 130 | * @return string |
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| 131 | * |
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| 132 | */ |
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| 133 | 242 | public function __toString() |
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| 134 | { |
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| 135 | 242 | return $this->getStatement(); |
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| 136 | } |
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| 137 | |||
| 138 | /** |
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| 139 | * |
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| 140 | * Returns this query object as an SQL statement string. |
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| 141 | * |
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| 142 | * @return string |
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| 143 | * |
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| 144 | */ |
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| 145 | 68 | public function getStatement() |
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| 146 | { |
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| 147 | 68 | return $this->build(); |
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| 148 | } |
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| 149 | |||
| 150 | /** |
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| 151 | * |
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| 152 | * Builds this query object into a string. |
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| 153 | * |
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| 154 | * @return string |
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| 155 | * |
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| 156 | */ |
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| 157 | abstract protected function build(); |
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| 158 | |||
| 159 | /** |
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| 160 | * |
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| 161 | * Returns the prefix to use when quoting identifier names. |
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| 162 | * |
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| 163 | * @return string |
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| 164 | * |
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| 165 | */ |
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| 166 | 251 | public function getQuoteNamePrefix() |
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| 170 | |||
| 171 | /** |
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| 172 | * |
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| 173 | * Returns the suffix to use when quoting identifier names. |
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| 174 | * |
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| 175 | * @return string |
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| 176 | * |
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| 177 | */ |
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| 178 | 251 | public function getQuoteNameSuffix() |
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| 182 | |||
| 183 | /** |
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| 184 | * |
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| 185 | * Returns an array as an indented comma-separated values string. |
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| 186 | * |
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| 187 | * @param array $list The values to convert. |
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| 188 | * |
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| 189 | * @return string |
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| 190 | * |
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| 191 | */ |
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| 192 | 219 | protected function indentCsv(array $list) |
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| 197 | |||
| 198 | /** |
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| 199 | * |
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| 200 | * Returns an array as an indented string. |
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| 201 | * |
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| 202 | * @param array $list The values to convert. |
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| 203 | * |
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| 204 | * @return string |
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| 205 | * |
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| 206 | */ |
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| 207 | 71 | protected function indent(array $list) |
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| 212 | |||
| 213 | /** |
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| 214 | * |
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| 215 | * Binds multiple values to placeholders; merges with existing values. |
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| 216 | * |
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| 217 | * @param array $bind_values Values to bind to placeholders. |
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| 218 | * |
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| 219 | * @return $this |
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| 220 | * |
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| 221 | */ |
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| 222 | 31 | public function bindValues(array $bind_values) |
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| 231 | |||
| 232 | /** |
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| 233 | * |
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| 234 | * Binds a single value to the query. |
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| 235 | * |
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| 236 | * @param string $name The placeholder name or number. |
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| 237 | * |
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| 238 | * @param mixed $value The value to bind to the placeholder. |
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| 239 | * |
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| 240 | * @return $this |
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| 241 | * |
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| 242 | */ |
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| 243 | 72 | public function bindValue($name, $value) |
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| 248 | |||
| 249 | /** |
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| 250 | * |
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| 251 | * Gets the values to bind to placeholders. |
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| 252 | * |
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| 253 | * @return array |
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| 254 | * |
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| 255 | */ |
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| 256 | 126 | public function getBindValues() |
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| 260 | |||
| 261 | /** |
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| 262 | * |
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| 263 | * Reset all values bound to named placeholders. |
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| 264 | * |
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| 265 | * @return $this |
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| 266 | * |
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| 267 | */ |
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| 268 | public function resetBindValues() |
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| 269 | { |
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| 270 | $this->bind_values = array(); |
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| 271 | return $this; |
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| 272 | } |
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| 273 | |||
| 274 | /** |
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| 275 | * |
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| 276 | * Builds the flags as a space-separated string. |
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| 277 | * |
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| 278 | * @return string |
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| 279 | * |
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| 280 | */ |
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| 281 | 252 | protected function buildFlags() |
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| 289 | |||
| 290 | /** |
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| 291 | * |
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| 292 | * Sets or unsets specified flag. |
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| 293 | * |
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| 294 | * @param string $flag Flag to set or unset |
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| 295 | * |
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| 296 | * @param bool $enable Flag status - enabled or not (default true) |
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| 297 | * |
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| 298 | * @return null |
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| 299 | * |
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| 300 | */ |
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| 301 | 43 | protected function setFlag($flag, $enable = true) |
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| 302 | { |
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| 303 | 43 | if ($enable) { |
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| 304 | 43 | $this->flags[$flag] = true; |
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| 305 | 43 | } else { |
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| 306 | 5 | unset($this->flags[$flag]); |
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| 307 | } |
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| 308 | 43 | } |
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| 309 | |||
| 310 | /** |
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| 311 | * |
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| 312 | * Reset all query flags. |
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| 313 | * |
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| 314 | * @return $this |
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| 315 | * |
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| 316 | */ |
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| 317 | 15 | public function resetFlags() |
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| 318 | { |
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| 319 | 15 | $this->flags = array(); |
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| 320 | 15 | return $this; |
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| 321 | } |
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| 322 | |||
| 323 | /** |
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| 324 | * |
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| 325 | * Adds a WHERE condition to the query by AND or OR. If the condition has |
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| 326 | * ?-placeholders, additional arguments to the method will be bound to |
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| 327 | * those placeholders sequentially. |
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| 328 | * |
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| 329 | * @param string $andor Add the condition using this operator, typically |
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| 330 | * 'AND' or 'OR'. |
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| 331 | * |
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| 332 | * @param array $args Arguments for adding the condition. |
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| 333 | * |
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| 334 | * @return $this |
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| 335 | * |
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| 336 | */ |
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| 337 | 60 | protected function addWhere($andor, $args) |
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| 342 | |||
| 343 | /** |
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| 344 | * |
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| 345 | * Adds conditions and binds values to a clause. |
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| 346 | * |
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| 347 | * @param string $clause The clause to work with, typically 'where' or |
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| 348 | * 'having'. |
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| 349 | * |
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| 350 | * @param string $andor Add the condition using this operator, typically |
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| 351 | * 'AND' or 'OR'. |
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| 352 | * |
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| 353 | * @param array $args Arguments for adding the condition. |
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| 354 | * |
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| 355 | * @return null |
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| 356 | * |
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| 357 | */ |
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| 358 | 70 | protected function addClauseCondWithBind($clause, $andor, $args) |
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| 372 | |||
| 373 | /** |
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| 374 | * |
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| 375 | * Rebuilds a condition string, replacing sequential placeholders with |
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| 376 | * named placeholders, and binding the sequential values to the named |
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| 377 | * placeholders. |
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| 378 | * |
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| 379 | * @param string $cond The condition with sequential placeholders. |
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| 380 | * |
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| 381 | * @param array $bind_values The values to bind to the sequential |
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| 382 | * placeholders under their named versions. |
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| 383 | * |
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| 384 | * @return string The rebuilt condition string. |
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| 385 | * |
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| 386 | */ |
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| 387 | 120 | protected function rebuildCondAndBindValues($cond, array $bind_values) |
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| 433 | |||
| 434 | /** |
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| 435 | * |
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| 436 | * Gets the current sequential placeholder name. |
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| 437 | * |
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| 438 | * @return string |
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| 439 | * |
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| 440 | */ |
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| 441 | 75 | protected function getSeqPlaceholder() |
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| 446 | |||
| 447 | /** |
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| 448 | * |
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| 449 | * Builds the `WHERE` clause of the statement. |
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| 450 | * |
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| 451 | * @return string |
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| 452 | * |
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| 453 | */ |
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| 454 | 206 | protected function buildWhere() |
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| 462 | |||
| 463 | /** |
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| 464 | * |
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| 465 | * Adds a column order to the query. |
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| 466 | * |
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| 467 | * @param array $spec The columns and direction to order by. |
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| 468 | * |
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| 469 | * @return $this |
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| 470 | * |
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| 471 | */ |
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| 472 | 9 | protected function addOrderBy(array $spec) |
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| 479 | |||
| 480 | /** |
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| 481 | * |
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| 482 | * Builds the `ORDER BY ...` clause of the statement. |
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| 483 | * |
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| 484 | * @return string |
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| 485 | * |
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| 486 | */ |
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| 487 | 206 | protected function buildOrderBy() |
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| 495 | |||
| 496 | /** |
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| 497 | * |
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| 498 | * Builds the `LIMIT ... OFFSET` clause of the statement. |
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| 499 | * |
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| 500 | * Note that this will allow OFFSET values with a LIMIT. |
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| 501 | * |
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| 502 | * @return string |
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| 503 | * |
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| 504 | */ |
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| 505 | 172 | protected function buildLimit() |
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| 525 | } |
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| 526 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)or! empty(...)instead.