Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Tables 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 Tables, and based on these observations, apply Extract Interface, too.
1 | <?php |
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39 | class Tables |
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40 | { |
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41 | /** |
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42 | * @var Connection |
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43 | */ |
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44 | protected $db; |
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45 | |||
46 | /** |
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47 | * @var string |
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48 | */ |
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49 | protected $databaseName; |
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50 | |||
51 | /** |
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52 | * @var array Tables |
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53 | */ |
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54 | protected $tables; |
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55 | |||
56 | /** |
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57 | * @var array Work queue |
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58 | */ |
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59 | protected $queue; |
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60 | |||
61 | /** |
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62 | * @var string last error message |
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63 | */ |
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64 | protected $lastError; |
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65 | |||
66 | /** |
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67 | * @var int last error number |
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68 | */ |
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69 | protected $lastErrNo; |
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70 | |||
71 | /** |
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72 | * Constructor |
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73 | * |
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74 | */ |
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75 | public function __construct() |
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83 | |||
84 | /** |
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85 | * Return a table name, prefixed with site table prefix |
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86 | * |
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87 | * @param string $table table name to contain prefix |
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88 | * |
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89 | * @return string table name with prefix |
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90 | */ |
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91 | 1 | protected function name($table) |
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95 | |||
96 | /** |
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97 | * Add new column for table to the work queue |
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98 | * |
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99 | * @param string $table table to contain the column |
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100 | * @param string $column name of column to add |
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101 | * @param string $attributes column_definition |
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102 | * |
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103 | * @return bool true if no errors, false if errors encountered |
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104 | */ |
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105 | 1 | public function addColumn($table, $column, $attributes) |
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133 | |||
134 | /** |
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135 | * Add new primary key definition for table to work queue |
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136 | * |
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137 | * @param string $table table |
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138 | * @param string $column column or comma separated list of columns |
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139 | * to use as primary key |
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140 | * |
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141 | * @return bool true if no errors, false if errors encountered |
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142 | */ |
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143 | 1 | public function addPrimaryKey($table, $column) |
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164 | |||
165 | /** |
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166 | * Add new index definition for index to work queue |
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167 | * |
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168 | * @param string $name name of index to add |
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169 | * @param string $table table indexed |
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170 | * @param string $column column or a comma separated list of columns |
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171 | * to use as the key |
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172 | * @param bool $unique true if index is to be unique |
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173 | * |
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174 | * @return bool true if no errors, false if errors encountered |
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175 | */ |
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176 | 1 | public function addIndex($name, $table, $column, $unique = false) |
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199 | |||
200 | /** |
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201 | * Load table schema from database, or starts new empty schema if |
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202 | * table does not exist |
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203 | * |
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204 | * @param string $table table |
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205 | * |
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206 | * @return bool true if no errors, false if errors encountered |
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207 | */ |
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208 | public function addTable($table) |
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237 | |||
238 | /** |
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239 | * AddTable only if it exists |
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240 | * |
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241 | * @param string $table table |
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242 | * |
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243 | * @return bool true if table exists, false otherwise |
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244 | */ |
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245 | 1 | public function useTable($table) |
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257 | |||
258 | /** |
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259 | * Get column attributes |
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260 | * |
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261 | * @param string $table table containing the column |
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262 | * @param string $column column to alter |
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263 | * |
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264 | * @return string|bool attribute string, or false if error encountered |
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265 | */ |
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266 | 1 | public function getColumnAttributes($table, $column) |
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281 | |||
282 | /** |
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283 | * Get indexes for a table |
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284 | * |
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285 | * @param string $table get indexes for this named table |
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286 | * |
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287 | * @return array|bool array of indexes, or false if error encountered |
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288 | */ |
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289 | 1 | public function getTableIndexes($table) |
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298 | |||
299 | /** |
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300 | * Add alter column operation to the work queue |
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301 | * |
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302 | * @param string $table table containing the column |
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303 | * @param string $column column to alter |
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304 | * @param string $attributes new column_definition |
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305 | * @param string $newName new name for column, blank to keep same |
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306 | * @param mixed $position FIRST, string of column name to add new |
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307 | * column after, or null for no change |
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308 | * |
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309 | * @return bool true if no errors, false if errors encountered |
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310 | */ |
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311 | 1 | public function alterColumn($table, $column, $attributes, $newName = '') |
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341 | |||
342 | /** |
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343 | * Loads table schema from database, and adds newTable with that |
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344 | * schema to the queue |
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345 | * |
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346 | * @param string $table existing table |
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347 | * @param string $newTable new table |
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348 | * @param bool $withData true to copy data, false for schema only |
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349 | * |
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350 | * @return bool true if no errors, false if errors encountered |
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351 | */ |
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352 | 1 | public function copyTable($table, $newTable, $withData = false) |
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377 | |||
378 | /** |
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379 | * Add new index definition for index to work queue |
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380 | * |
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381 | * @param string $name name of index to add |
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382 | * @param string $table table indexed |
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383 | * @param string $column column or comma separated list of columns |
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384 | * to use as the key |
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385 | * @param bool $unique true if index is to be unique |
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386 | * |
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387 | * @return bool true if no errors, false if errors encountered |
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388 | */ |
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389 | public function createIndex($name, $table, $column, $unique = false) |
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405 | |||
406 | /** |
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407 | * Add drop column operation to the work queue |
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408 | * |
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409 | * @param string $table table containing the column |
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410 | * @param string $column column to drop |
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411 | * |
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412 | * @return bool true if no errors, false if errors encountered |
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413 | */ |
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414 | 1 | View Code Duplication | public function dropColumn($table, $column) |
426 | |||
427 | /** |
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428 | * Add drop index operation to the work queue |
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429 | * |
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430 | * @param string $name name of index to drop |
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431 | * @param string $table table indexed |
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432 | * |
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433 | * @return bool true if no errors, false if errors encountered |
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434 | */ |
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435 | 1 | View Code Duplication | public function dropIndex($name, $table) |
446 | |||
447 | /** |
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448 | * Add drop for all (non-PRIMARY) keys for a table to the work |
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449 | * queue. This can be used to clean up indexes with automatic names. |
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450 | * |
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451 | * @param string $table table indexed |
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452 | * |
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453 | * @return bool true if no errors, false if errors encountered |
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454 | */ |
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455 | public function dropIndexes($table) |
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482 | |||
483 | /** |
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484 | * Add drop of PRIMARY key for a table to the work queue |
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485 | * |
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486 | * @param string $table table |
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487 | * |
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488 | * @return bool true if no errors, false if errors encountered |
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489 | */ |
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490 | 1 | View Code Duplication | public function dropPrimaryKey($table) |
501 | |||
502 | /** |
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503 | * Add drop of table to the work queue |
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504 | * |
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505 | * @param string $table table |
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506 | * |
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507 | * @return bool true if no errors, false if errors encountered |
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508 | */ |
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509 | 1 | View Code Duplication | public function dropTable($table) |
519 | |||
520 | |||
521 | /** |
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522 | * Add rename table operation to the work queue |
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523 | * |
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524 | * @param string $table table |
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525 | * @param string $newName new table name |
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526 | * |
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527 | * @return bool true if no errors, false if errors encountered |
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528 | */ |
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529 | 1 | public function renameTable($table, $newName) |
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544 | |||
545 | /** |
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546 | * Add alter table table_options (ENGINE, DEFAULT CHARSET, etc.) |
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547 | * to work queue |
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548 | * |
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549 | * @param string $table table |
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550 | * @param array $options table_options |
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551 | * |
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552 | * @return bool true if no errors, false if errors encountered |
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553 | */ |
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554 | 1 | public function setTableOptions($table, $options) |
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575 | |||
576 | |||
577 | /** |
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578 | * Clear the work queue |
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579 | * |
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580 | * @return void |
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581 | */ |
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582 | public function resetQueue() |
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587 | |||
588 | /** |
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589 | * Executes the work queue |
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590 | * |
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591 | * @param bool $force true to force updates even if this is a 'GET' request |
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592 | * |
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593 | * @return bool true if no errors, false if errors encountered |
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594 | */ |
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595 | public function executeQueue($force = false) |
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615 | |||
616 | |||
617 | /** |
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618 | * Create a DELETE statement and add it to the work queue |
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619 | * |
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620 | * @param string $table table |
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621 | * @param string|CriteriaElement $criteria string where clause or object criteria |
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622 | * |
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623 | * @return bool true if no errors, false if errors encountered |
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624 | */ |
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625 | public function delete($table, $criteria) |
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642 | |||
643 | /** Create an INSERT SQL statement and add it to the work queue. |
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644 | * |
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645 | * @param string $table table |
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646 | * @param array $columns array of 'column'=>'value' entries |
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647 | * |
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648 | * @return boolean true if no errors, false if errors encountered |
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649 | */ |
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650 | public function insert($table, $columns) |
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671 | |||
672 | /** |
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673 | * Create an UPDATE SQL statement and add it to the work queue |
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674 | * |
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675 | * @param string $table table |
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676 | * @param array $columns array of 'column'=>'value' entries |
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677 | * @param string|CriteriaElement $criteria string where clause or object criteria |
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678 | * |
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679 | * @return boolean true if no errors, false if errors encountered |
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680 | */ |
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681 | public function update($table, $columns, $criteria) |
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707 | |||
708 | /** |
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709 | * Add statement to remove all rows from a table to the work queue |
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710 | * |
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711 | * @param string $table table |
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712 | * |
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713 | * @return bool true if no errors, false if errors encountered |
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714 | */ |
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715 | View Code Duplication | public function truncate($table) |
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726 | |||
727 | |||
728 | |||
729 | /** |
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730 | * return SQL to create the table |
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731 | * |
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732 | * This method does NOT modify the work queue |
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733 | * |
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734 | * @param string $table table |
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735 | * @param bool $prefixed true to return with table name prefixed |
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736 | * |
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737 | * @return string|false string SQL to create table, or false if errors encountered |
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738 | */ |
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739 | protected function renderTableCreate($table, $prefixed = false) |
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767 | |||
768 | /** |
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769 | * execute an SQL statement |
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770 | * |
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771 | * @param string $sql SQL statement to execute |
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772 | * @param bool $force true to use force updates even in safe requests |
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773 | * |
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774 | * @return mixed result Statement, or false on error |
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775 | * Any error message is in $this->lastError; |
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776 | */ |
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777 | protected function execSql($sql, $force = false) |
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791 | |||
792 | /** |
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793 | * fetch the next row of a result set |
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794 | * |
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795 | * @param Statement $result as returned by query |
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796 | * |
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797 | * @return mixed false on error |
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798 | */ |
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799 | protected function fetch($result) |
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803 | |||
804 | /** |
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805 | * get table definition from INFORMATION_SCHEMA |
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806 | * |
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807 | * @param string $table table |
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808 | * |
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809 | * @return array|bool table definition array if table exists, true if table not defined, or |
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810 | * false on error. Error message in $this->lastError; |
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811 | */ |
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812 | protected function getTable($table) |
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896 | |||
897 | /** |
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898 | * During processing, tables to be created are put in the queue as |
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899 | * an array('createtable' => tablename) since the definition is not |
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900 | * complete. This method will expand those references to the full |
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901 | * ddl to create the table. |
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902 | * |
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903 | * @return void |
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904 | */ |
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905 | protected function expandQueue() |
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915 | |||
916 | /** |
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917 | * Return message from last error encountered |
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918 | * |
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919 | * @return string last error message |
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920 | */ |
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921 | public function getLastError() |
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925 | |||
926 | /** |
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927 | * Return code from last error encountered |
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928 | * |
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929 | * @return int last error number |
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930 | */ |
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931 | public function getLastErrNo() |
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935 | |||
936 | /** |
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937 | * dumpTables - development function to dump raw tables array |
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938 | * |
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939 | * @return array tables |
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940 | */ |
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941 | public function dumpTables() |
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945 | |||
946 | /** |
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947 | * dumpQueue - development function to dump the work queue |
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948 | * |
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949 | * @return array work queue |
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950 | */ |
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951 | public function dumpQueue() |
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957 | |||
958 | /** |
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959 | * Set lastError as table not established |
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960 | * |
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961 | * @return false |
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962 | */ |
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963 | protected function tableNotEstablished() |
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969 | } |
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970 |
This check looks for PHPDoc comments describing methods or function parameters that do not exist on the corresponding method or function.
Consider the following example. The parameter
$italy
is not defined by the methodfinale(...)
.The most likely cause is that the parameter was removed, but the annotation was not.