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 Query 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 Query, and based on these observations, apply Extract Interface, too.
1 | <?php |
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19 | class Query |
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20 | { |
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21 | const DEFAULT_LIMIT = 100; |
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22 | const MAX_LIMIT = 1000; |
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23 | |||
24 | /** |
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25 | * @var Model|string |
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26 | */ |
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27 | private $model; |
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28 | |||
29 | /** |
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30 | * @var array |
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31 | */ |
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32 | private $joins; |
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33 | |||
34 | /** |
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35 | * @var array |
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36 | */ |
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37 | private $eagerLoaded; |
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38 | |||
39 | /** |
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40 | * @var array |
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41 | */ |
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42 | private $where; |
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43 | |||
44 | /** |
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45 | * @var int |
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46 | */ |
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47 | private $limit; |
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48 | |||
49 | /** |
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50 | * @var int |
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51 | */ |
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52 | private $start; |
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53 | |||
54 | /** |
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55 | * @var array |
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56 | */ |
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57 | private $sort; |
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58 | |||
59 | /** |
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60 | * @param Model|string $model |
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61 | */ |
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62 | public function __construct($model = '') |
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63 | { |
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64 | $this->model = $model; |
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65 | $this->joins = []; |
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66 | $this->eagerLoaded = []; |
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67 | $this->where = []; |
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68 | $this->start = 0; |
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69 | $this->limit = self::DEFAULT_LIMIT; |
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70 | $this->sort = []; |
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71 | } |
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72 | |||
73 | /** |
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74 | * Gets the model class associated with this query. |
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75 | * |
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76 | * @return Model|string |
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77 | */ |
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78 | public function getModel() |
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79 | { |
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80 | return $this->model; |
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81 | } |
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82 | |||
83 | /** |
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84 | * Sets the limit for this query. |
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85 | * |
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86 | * @return $this |
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87 | */ |
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88 | public function limit(int $limit) |
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94 | |||
95 | /** |
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96 | * Gets the limit for this query. |
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97 | */ |
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98 | public function getLimit(): int |
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102 | |||
103 | /** |
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104 | * Sets the start offset. |
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105 | * |
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106 | * @return $this |
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107 | */ |
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108 | public function start(int $start) |
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114 | |||
115 | /** |
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116 | * Gets the start offset. |
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117 | */ |
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118 | public function getStart(): int |
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122 | |||
123 | /** |
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124 | * Sets the sort pattern for the query. |
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125 | * |
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126 | * @param array|string $sort |
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127 | * |
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128 | * @return $this |
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129 | */ |
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130 | public function sort($sort) |
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155 | |||
156 | /** |
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157 | * Gets the sort parameters. |
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158 | */ |
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159 | public function getSort(): array |
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163 | |||
164 | /** |
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165 | * Sets the where parameters. |
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166 | * Accepts the following forms: |
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167 | * i) where(['name' => 'Bob']) |
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168 | * ii) where('name', 'Bob') |
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169 | * iii) where('balance', 100, '>') |
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170 | * iv) where('balance > 100'). |
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171 | * |
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172 | * @param array|string $where |
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173 | * @param mixed $value optional value |
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174 | * @param string|null $condition optional condition |
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175 | * |
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176 | * @return $this |
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177 | */ |
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178 | public function where($where, $value = null, $condition = null) |
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199 | |||
200 | /** |
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201 | * Gets the where parameters. |
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202 | */ |
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203 | public function getWhere(): array |
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207 | |||
208 | /** |
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209 | * Adds a join to the query. Matches a property on this model |
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210 | * to the ID of the model we are joining. |
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211 | * |
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212 | * @param string $model model being joined |
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213 | * @param string $column name of local property |
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214 | * |
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215 | * @return $this |
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216 | */ |
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217 | public function join($model, string $column, string $foreignKey) |
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223 | |||
224 | /** |
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225 | * Gets the joins. |
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226 | */ |
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227 | public function getJoins(): array |
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231 | |||
232 | /** |
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233 | * Marks a relationship property on the model that should be eager loaded. |
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234 | * |
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235 | * @param string $k local property containing the relationship |
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236 | * |
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237 | * @return $this |
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238 | */ |
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239 | public function with(string $k) |
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247 | |||
248 | /** |
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249 | * Gets the relationship properties that are going to be eager-loaded. |
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250 | */ |
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251 | public function getWith(): array |
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255 | |||
256 | /** |
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257 | * Executes the query against the model's driver. |
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258 | * |
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259 | * @return array results |
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260 | */ |
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261 | public function execute(): array |
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363 | |||
364 | /** |
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365 | * Creates an iterator for a search. |
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366 | * |
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367 | * @return Iterator |
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368 | */ |
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369 | public function all() |
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373 | |||
374 | /** |
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375 | * Executes the query against the model's driver and returns the first result. |
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376 | * |
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377 | * @return array|Model|null when $limit = 1, returns a single model or null, otherwise returns an array |
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378 | */ |
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379 | public function first(int $limit = 1) |
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389 | |||
390 | /** |
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391 | * Gets the number of models matching the query. |
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392 | */ |
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393 | public function count(): int |
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400 | |||
401 | /** |
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402 | * Gets the sum of a property matching the query. |
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403 | * |
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404 | * @return number |
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405 | */ |
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406 | public function sum(string $property) |
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413 | |||
414 | /** |
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415 | * Gets the average of a property matching the query. |
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416 | * |
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417 | * @return number |
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418 | */ |
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419 | public function average(string $property) |
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426 | |||
427 | /** |
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428 | * Gets the max of a property matching the query. |
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429 | * |
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430 | * @return number |
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431 | */ |
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432 | public function max(string $property) |
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439 | |||
440 | /** |
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441 | * Gets the min of a property matching the query. |
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442 | * |
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443 | * @return number |
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444 | */ |
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445 | public function min(string $property) |
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452 | |||
453 | /** |
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454 | * Updates all of the models matched by this query. |
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455 | * |
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456 | * @todo should be optimized to be done in a single call to the data layer |
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457 | * |
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458 | * @param array $params key-value update parameters |
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459 | * |
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460 | * @return int # of models updated |
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461 | */ |
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462 | public function set(array $params): int |
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472 | |||
473 | /** |
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474 | * Deletes all of the models matched by this query. |
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475 | * |
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476 | * @todo should be optimized to be done in a single call to the data layer |
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477 | * |
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478 | * @return int # of models deleted |
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479 | */ |
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480 | public function delete(): int |
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490 | |||
491 | /** |
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492 | * Hydrates the eager-loaded relationships for a given set of IDs. |
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493 | * |
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494 | * @param string $modelClass |
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495 | * @param bool $multiple when true will condense |
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496 | * |
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497 | * @return Model[] |
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498 | */ |
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499 | private function fetchRelationships($modelClass, array $ids, string $foreignKey, bool $multiple): array |
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524 | } |
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525 |
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVar
assignment in line 1 and the$higher
assignment in line 2 are dead. The first because$myVar
is never used and the second because$higher
is always overwritten for every possible time line.