Complex classes like SqlSelect 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 SqlSelect, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 15 | class SqlSelect extends SqlActions |
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| 16 | { |
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| 17 | /** |
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| 18 | * @var string $returnType PHP Type used for return result |
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| 19 | */ |
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| 20 | protected $returnType = ''; |
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| 21 | |||
| 22 | /** |
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| 23 | * @var object $mainTable Informations about main table. Used for FROM part |
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| 24 | */ |
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| 25 | protected $mainTable; |
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| 26 | |||
| 27 | /** |
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| 28 | * @var array $subQueries All sub-queries |
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| 29 | */ |
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| 30 | protected $subQueries = []; |
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| 31 | |||
| 32 | /** |
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| 33 | * @var array $join List of all INNER JOIN |
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| 34 | */ |
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| 35 | protected $join = []; |
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| 36 | |||
| 37 | /** |
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| 38 | * @var array $joinLeft List of all LEFT JOIN |
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| 39 | */ |
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| 40 | protected $joinLeft = []; |
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| 41 | |||
| 42 | /** |
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| 43 | * @var array $joinRight List of all RIGHT JOIN |
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| 44 | */ |
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| 45 | protected $joinRight = []; |
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| 46 | |||
| 47 | /** |
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| 48 | * @var string[] $order All columns used for ORDER BY part |
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| 49 | */ |
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| 50 | protected $order = []; |
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| 51 | |||
| 52 | /** |
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| 53 | * @var string $limit The LIMIT part |
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| 54 | */ |
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| 55 | protected $limit = ''; |
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| 56 | |||
| 57 | /** |
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| 58 | * @var string[] $group The GROUP BY part |
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| 59 | */ |
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| 60 | protected $group = []; |
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| 61 | |||
| 62 | /** |
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| 63 | * Constructor |
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| 64 | * |
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| 65 | * @param \BfwSql\SqlConnect $sqlConnect Instance of SGBD connexion |
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| 66 | * @param string $returnType PHP type used for return result |
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| 67 | */ |
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| 68 | public function __construct(SqlConnect $sqlConnect, $returnType) |
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| 73 | |||
| 74 | /** |
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| 75 | * Define object used to save informations about a table |
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| 76 | * This object will be used to write query |
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| 77 | * |
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| 78 | * @param string|array $table Tables informations |
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| 79 | * |
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| 80 | * @return \stdClass |
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| 81 | */ |
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| 82 | protected function obtainTableInfos($table) |
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| 105 | |||
| 106 | /** |
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| 107 | * Add columns for select |
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| 108 | * |
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| 109 | * @param array|string $columns Columns to add |
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| 110 | * @param string $tableName Table name for will be columns added |
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| 111 | * |
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| 112 | * @return void |
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| 113 | */ |
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| 114 | protected function addColumnsForSelect($columns, $tableName) |
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| 148 | |||
| 149 | /** |
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| 150 | * Declare information for FROM part and column will be get for main table |
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| 151 | * |
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| 152 | * @param string|array $table Table name. |
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| 153 | * It can be an array if a table shortcut is declared. |
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| 154 | * In array mode, the format is ['asValue' => 'tableName'] |
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| 155 | * @param string|array $columns (default: "*") Columns will be get for |
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| 156 | * the table declared in first argument |
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| 157 | * |
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| 158 | * @return \BfwSql\SqlSelect |
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| 159 | */ |
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| 160 | public function from($table, $columns = '*') |
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| 173 | |||
| 174 | /** |
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| 175 | * Add a sub-query in the SELECT part on the request |
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| 176 | * |
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| 177 | * @param \BfwSql\SqlActions|string $subRequest The sub-request |
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| 178 | * @param string $shortcut The shortcut to use for |
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| 179 | * this query in SELECT part |
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| 180 | * |
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| 181 | * @return \BfwSql\SqlSelect |
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| 182 | */ |
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| 183 | public function subQuery($subRequest, $shortcut) |
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| 206 | |||
| 207 | /** |
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| 208 | * Add a (inner|left|right) join to the request |
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| 209 | * |
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| 210 | * @param string $joinPropertyName The name of the property in this |
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| 211 | * class where the join is add |
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| 212 | * @param string|array $table Name of the table concerned by |
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| 213 | * the join. Or an array with the table shortcut in key. |
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| 214 | * @param string $joinOn SQL part "ON" for this join |
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| 215 | * @param string|array $joinColumns Columns from the table joined to |
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| 216 | * add in the SELECT part of the request |
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| 217 | * |
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| 218 | * @return \BfwSql\SqlSelect |
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| 219 | */ |
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| 220 | protected function createJoin( |
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| 239 | |||
| 240 | /** |
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| 241 | * Add a INNER JOIN to the request |
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| 242 | * |
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| 243 | * @param string|array $table Name of the table concerned by the |
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| 244 | * join. Or an array with the table shortcut in key. |
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| 245 | * @param string $joinOn SQL part "ON" for this join |
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| 246 | * @param string|array $joinColumns Columns from the table joined to add |
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| 247 | * in the SELECT part of the request |
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| 248 | * |
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| 249 | * @return \BfwSql\SqlSelect |
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| 250 | */ |
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| 251 | public function join($table, $joinOn, $joinColumns = '*') |
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| 255 | |||
| 256 | /** |
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| 257 | * Add a LEFT JOIN to the request |
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| 258 | * |
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| 259 | * @param string|array $table Name of the table concerned by the |
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| 260 | * join. Or an array with the table shortcut in key. |
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| 261 | * @param string $joinOn SQL part "ON" for this join |
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| 262 | * @param string|array $joinColumns Columns from the table joined to add |
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| 263 | * in the SELECT part of the request |
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| 264 | * |
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| 265 | * @return \BfwSql\SqlSelect |
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| 266 | */ |
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| 267 | public function joinLeft($table, $joinOn, $joinColumns = '*') |
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| 271 | |||
| 272 | /** |
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| 273 | * Add a RIGHT JOIN to the request |
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| 274 | * |
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| 275 | * @param string|array $table Name of the table concerned by the |
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| 276 | * join. Or an array with the table shortcut in key. |
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| 277 | * @param string $joinOn SQL part "ON" for this join |
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| 278 | * @param string|array $joinColumns Columns from the table joined to add |
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| 279 | * in the SELECT part of the request |
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| 280 | * |
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| 281 | * @return \BfwSql\SqlSelect |
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| 282 | */ |
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| 283 | public function joinRight($table, $joinOn, $joinColumns = '*') |
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| 287 | |||
| 288 | /** |
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| 289 | * Add a order condition to the request for the ORDER BY part |
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| 290 | * |
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| 291 | * @param string $condition The new condition |
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| 292 | * |
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| 293 | * @return \BfwSql\SqlSelect |
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| 294 | */ |
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| 295 | public function order($condition) |
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| 300 | |||
| 301 | /** |
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| 302 | * Add information about the LIMIT part in request |
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| 303 | * |
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| 304 | * @param array|integer $limit If it's a integer, the number of row to |
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| 305 | * return. If an array, the format is [numberToStart, numberOfRowToReturn] |
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| 306 | * |
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| 307 | * @return \BfwSql\SqlSelect |
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| 308 | */ |
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| 309 | public function limit($limit) |
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| 323 | |||
| 324 | /** |
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| 325 | * Add a GROUP BY part to the request |
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| 326 | * |
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| 327 | * @param string $condition The condition to use in GROUP BY |
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| 328 | * |
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| 329 | * @return \BfwSql\SqlSelect |
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| 330 | */ |
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| 331 | public function group($condition) |
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| 336 | |||
| 337 | /** |
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| 338 | * Return the PDO constant for the returnType declared |
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| 339 | * |
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| 340 | * @return integer |
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| 341 | */ |
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| 342 | protected function obtainPdoFetchType() |
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| 350 | |||
| 351 | /** |
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| 352 | * Fetch one row of the result |
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| 353 | * |
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| 354 | * @return mixed |
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| 355 | */ |
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| 356 | public function fetchRow() |
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| 361 | |||
| 362 | /** |
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| 363 | * Fetch all rows returned by the request |
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| 364 | * |
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| 365 | * @return generator |
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| 366 | */ |
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| 367 | public function fetchAll() |
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| 375 | |||
| 376 | /** |
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| 377 | * {@inheritdoc} |
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| 378 | */ |
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| 379 | protected function assembleRequest() |
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| 393 | |||
| 394 | /** |
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| 395 | * Write the SELECT part of the request |
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| 396 | * |
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| 397 | * @return string |
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| 398 | */ |
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| 399 | protected function generateSelect() |
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| 424 | |||
| 425 | /** |
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| 426 | * Write the FROM part of the request |
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| 427 | * |
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| 428 | * @return string |
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| 429 | */ |
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| 430 | protected function generateFrom() |
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| 440 | |||
| 441 | /** |
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| 442 | * Write a (inner|left|right) join in the request |
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| 443 | * |
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| 444 | * @param string $joinProperty The join property name |
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| 445 | * |
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| 446 | * @return string |
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| 447 | */ |
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| 448 | protected function generateJoin($joinProperty) |
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| 474 | |||
| 475 | /** |
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| 476 | * Write the ORDER BY part for the request |
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| 477 | * |
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| 478 | * @return string |
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| 479 | */ |
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| 480 | protected function generateOrderBy() |
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| 497 | |||
| 498 | /** |
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| 499 | * Write the GRUOP BY part for the request |
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| 500 | * |
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| 501 | * @return string |
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| 502 | */ |
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| 503 | protected function generateGroupBy() |
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| 520 | |||
| 521 | /** |
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| 522 | * Write the LIMIT part for the request |
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| 523 | * |
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| 524 | * @return string |
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| 525 | */ |
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| 526 | protected function generateLimit() |
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| 535 | } |
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| 536 |