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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36 | class Tables |
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37 | { |
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38 | /** |
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39 | * @var \XoopsDatabase |
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40 | */ |
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41 | protected $db; |
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42 | |||
43 | /** |
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44 | * @var string |
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45 | */ |
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46 | protected $databaseName; |
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47 | |||
48 | /** |
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49 | * @var array Tables |
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50 | */ |
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51 | protected $tables; |
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52 | |||
53 | /** |
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54 | * @var array Work queue |
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55 | */ |
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56 | protected $queue; |
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57 | |||
58 | /** |
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59 | * @var string last error message |
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60 | */ |
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61 | protected $lastError; |
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62 | |||
63 | /** |
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64 | * @var int last error number |
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65 | */ |
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66 | protected $lastErrNo; |
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67 | |||
68 | /** |
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69 | * Constructor |
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70 | * |
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71 | */ |
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72 | public function __construct() |
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80 | |||
81 | /** |
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82 | * Return a table name, prefixed with site table prefix |
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83 | * |
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84 | * @param string $table table name to contain prefix |
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85 | * |
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86 | * @return string table name with prefix |
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87 | */ |
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88 | protected function name($table) |
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92 | |||
93 | /** |
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94 | * Add new column for table to the work queue |
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95 | * |
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96 | * @param string $table table to contain the column |
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97 | * @param string $column name of column to add |
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98 | * @param string $attributes column_definition |
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99 | * |
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100 | * @return bool true if no errors, false if errors encountered |
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101 | */ |
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102 | public function addColumn($table, $column, $attributes) |
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130 | |||
131 | /** |
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132 | * Add new primary key definition for table to work queue |
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133 | * |
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134 | * @param string $table table |
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135 | * @param string $column column or comma separated list of columns |
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136 | * to use as primary key |
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137 | * |
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138 | * @return bool true if no errors, false if errors encountered |
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139 | */ |
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140 | public function addPrimaryKey($table, $column) |
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161 | |||
162 | /** |
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163 | * Add new index definition for index to work queue |
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164 | * |
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165 | * @param string $name name of index to add |
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166 | * @param string $table table indexed |
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167 | * @param string $column column or a comma separated list of columns |
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168 | * to use as the key |
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169 | * @param bool $unique true if index is to be unique |
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170 | * |
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171 | * @return bool true if no errors, false if errors encountered |
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172 | */ |
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173 | public function addIndex($name, $table, $column, $unique = false) |
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196 | |||
197 | /** |
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198 | * Load table schema from database, or starts new empty schema if |
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199 | * table does not exist |
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200 | * |
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201 | * @param string $table table |
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202 | * |
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203 | * @return bool true if no errors, false if errors encountered |
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204 | */ |
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205 | public function addTable($table) |
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234 | |||
235 | /** |
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236 | * AddTable only if it exists |
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237 | * |
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238 | * @param string $table table |
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239 | * |
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240 | * @return bool true if table exists, false otherwise |
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241 | */ |
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242 | public function useTable($table) |
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254 | |||
255 | /** |
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256 | * Get column attributes |
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257 | * |
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258 | * @param string $table table containing the column |
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259 | * @param string $column column to alter |
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260 | * |
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261 | * @return string|bool attribute string, or false if error encountered |
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262 | */ |
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263 | public function getColumnAttributes($table, $column) |
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278 | |||
279 | /** |
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280 | * Get indexes for a table |
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281 | * |
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282 | * @param string $table get indexes for this named table |
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283 | * |
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284 | * @return array|bool array of indexes, or false if error encountered |
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285 | */ |
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286 | public function getTableIndexes($table) |
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295 | |||
296 | /** |
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297 | * Add alter column operation to the work queue |
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298 | * |
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299 | * @param string $table table containing the column |
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300 | * @param string $column column to alter |
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301 | * @param string $attributes new column_definition |
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302 | * @param string $newName new name for column, blank to keep same |
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303 | * |
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304 | * @return bool true if no errors, false if errors encountered |
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305 | */ |
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306 | public function alterColumn($table, $column, $attributes, $newName = '') |
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336 | |||
337 | /** |
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338 | * Loads table schema from database, and adds newTable with that |
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339 | * schema to the queue |
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340 | * |
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341 | * @param string $table existing table |
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342 | * @param string $newTable new table |
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343 | * @param bool $withData true to copy data, false for schema only |
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344 | * |
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345 | * @return bool true if no errors, false if errors encountered |
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346 | */ |
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347 | public function copyTable($table, $newTable, $withData = false) |
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372 | |||
373 | /** |
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374 | * Add drop column operation to the work queue |
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375 | * |
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376 | * @param string $table table containing the column |
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377 | * @param string $column column to drop |
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378 | * |
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379 | * @return bool true if no errors, false if errors encountered |
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380 | */ |
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381 | View Code Duplication | public function dropColumn($table, $column) |
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393 | |||
394 | /** |
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395 | * Add drop index operation to the work queue |
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396 | * |
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397 | * @param string $name name of index to drop |
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398 | * @param string $table table indexed |
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399 | * |
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400 | * @return bool true if no errors, false if errors encountered |
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401 | */ |
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402 | View Code Duplication | public function dropIndex($name, $table) |
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413 | |||
414 | /** |
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415 | * Add drop for all (non-PRIMARY) keys for a table to the work |
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416 | * queue. This can be used to clean up indexes with automatic names. |
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417 | * |
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418 | * @param string $table table indexed |
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419 | * |
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420 | * @return bool true if no errors, false if errors encountered |
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421 | */ |
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422 | public function dropIndexes($table) |
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449 | |||
450 | /** |
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451 | * Add drop of PRIMARY key for a table to the work queue |
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452 | * |
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453 | * @param string $table table |
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454 | * |
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455 | * @return bool true if no errors, false if errors encountered |
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456 | */ |
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457 | View Code Duplication | public function dropPrimaryKey($table) |
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468 | |||
469 | /** |
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470 | * Add drop of table to the work queue |
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471 | * |
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472 | * @param string $table table |
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473 | * |
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474 | * @return bool true if no errors, false if errors encountered |
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475 | */ |
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476 | View Code Duplication | public function dropTable($table) |
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486 | |||
487 | |||
488 | /** |
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489 | * Add rename table operation to the work queue |
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490 | * |
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491 | * @param string $table table |
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492 | * @param string $newName new table name |
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493 | * |
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494 | * @return bool true if no errors, false if errors encountered |
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495 | */ |
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496 | public function renameTable($table, $newName) |
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511 | |||
512 | /** |
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513 | * Add alter table table_options (ENGINE, DEFAULT CHARSET, etc.) |
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514 | * to work queue |
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515 | * |
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516 | * @param string $table table |
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517 | * @param array $options table_options |
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518 | * |
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519 | * @return bool true if no errors, false if errors encountered |
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520 | */ |
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521 | public function setTableOptions($table, $options) |
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538 | |||
539 | |||
540 | /** |
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541 | * Clear the work queue |
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542 | * |
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543 | * @return void |
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544 | */ |
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545 | public function resetQueue() |
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550 | |||
551 | /** |
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552 | * Executes the work queue |
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553 | * |
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554 | * @param bool $force true to force updates even if this is a 'GET' request |
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555 | * |
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556 | * @return bool true if no errors, false if errors encountered |
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557 | */ |
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558 | public function executeQueue($force = false) |
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578 | |||
579 | |||
580 | /** |
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581 | * Create a DELETE statement and add it to the work queue |
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582 | * |
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583 | * @param string $table table |
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584 | * @param string|CriteriaElement $criteria string where clause or object criteria |
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585 | * |
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586 | * @return bool true if no errors, false if errors encountered |
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587 | */ |
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588 | public function delete($table, $criteria) |
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605 | |||
606 | /** Create an INSERT SQL statement and add it to the work queue. |
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607 | * |
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608 | * @param string $table table |
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609 | * @param array $columns array of 'column'=>'value' entries |
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610 | * |
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611 | * @return boolean true if no errors, false if errors encountered |
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612 | */ |
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613 | public function insert($table, $columns) |
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634 | |||
635 | /** |
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636 | * Create an UPDATE SQL statement and add it to the work queue |
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637 | * |
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638 | * @param string $table table |
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639 | * @param array $columns array of 'column'=>'value' entries |
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640 | * @param string|CriteriaElement $criteria string where clause or object criteria |
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641 | * |
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642 | * @return boolean true if no errors, false if errors encountered |
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643 | */ |
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644 | public function update($table, $columns, $criteria) |
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670 | |||
671 | /** |
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672 | * Add statement to remove all rows from a table to the work queue |
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673 | * |
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674 | * @param string $table table |
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675 | * |
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676 | * @return bool true if no errors, false if errors encountered |
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677 | */ |
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678 | View Code Duplication | public function truncate($table) |
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689 | |||
690 | |||
691 | |||
692 | /** |
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693 | * return SQL to create the table |
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694 | * |
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695 | * This method does NOT modify the work queue |
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696 | * |
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697 | * @param string $table table |
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698 | * @param bool $prefixed true to return with table name prefixed |
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699 | * |
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700 | * @return string|false string SQL to create table, or false if errors encountered |
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701 | */ |
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702 | protected function renderTableCreate($table, $prefixed = false) |
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730 | |||
731 | /** |
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732 | * execute an SQL statement |
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733 | * |
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734 | * @param string $sql SQL statement to execute |
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735 | * @param bool $force true to use force updates even in safe requests |
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736 | * |
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737 | * @return mixed result resource if no error, |
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738 | * true if no error but no result |
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739 | * false if error encountered. |
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740 | * Any error message is in $this->lastError; |
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741 | */ |
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742 | protected function execSql($sql, $force = false) |
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757 | |||
758 | /** |
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759 | * fetch the next row of a result set |
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760 | * |
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761 | * @param resource $result as returned by query |
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762 | * |
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763 | * @return mixed false on error |
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764 | */ |
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765 | protected function fetch($result) |
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769 | |||
770 | /** |
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771 | * get table definition from INFORMATION_SCHEMA |
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772 | * |
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773 | * @param string $table table |
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774 | * |
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775 | * @return array|bool table definition array if table exists, true if table not defined, or |
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776 | * false on error. Error message in $this->lastError; |
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777 | */ |
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778 | protected function getTable($table) |
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861 | |||
862 | /** |
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863 | * During processing, tables to be created are put in the queue as |
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864 | * an array('createtable' => tablename) since the definition is not |
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865 | * complete. This method will expand those references to the full |
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866 | * ddl to create the table. |
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867 | * |
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868 | * @return void |
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869 | */ |
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870 | protected function expandQueue() |
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880 | |||
881 | /** |
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882 | * Return message from last error encountered |
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883 | * |
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884 | * @return string last error message |
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885 | */ |
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886 | public function getLastError() |
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890 | |||
891 | /** |
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892 | * Return code from last error encountered |
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893 | * |
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894 | * @return int last error number |
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895 | */ |
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896 | public function getLastErrNo() |
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900 | |||
901 | /** |
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902 | * dumpTables - development function to dump raw tables array |
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903 | * |
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904 | * @return array tables |
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905 | */ |
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906 | public function dumpTables() |
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910 | |||
911 | /** |
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912 | * dumpQueue - development function to dump the work queue |
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913 | * |
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914 | * @return array work queue |
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915 | */ |
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916 | public function dumpQueue() |
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922 | |||
923 | /** |
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924 | * Set lastError as table not established |
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925 | * |
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926 | * @return false |
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927 | */ |
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928 | protected function tableNotEstablished() |
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934 | } |
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935 |
This check compares the return type specified in the
@return
annotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.