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:
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12 | final class MySqlConnection implements Connection |
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13 | { |
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14 | use LoadEnvVariablesTrait, DatabaseTransactionsTrait; |
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17 | * The method called in the constructor. |
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18 | * |
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19 | * @return void |
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20 | */ |
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21 | private function __construct() |
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36 | * Returns the columns of a table. |
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37 | * |
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38 | * @param string $table The table inspected for its columns. |
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39 | * |
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40 | * @return array The columns of the table. |
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41 | */ |
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42 | View Code Duplication | public function getColumns($table) |
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54 | /** |
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55 | * Returns the Connection's PDO. |
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56 | * |
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57 | * @return PDO PHP Data Objects |
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58 | */ |
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59 | public function getPdo() |
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64 | /** |
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65 | * Returns the primary key of a table. |
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66 | * |
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67 | * @param string $table The table inspected for its primary key. |
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68 | * |
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69 | * @return string The primary key of the table. |
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70 | */ |
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71 | View Code Duplication | public function getPrimaryKey($table) |
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80 | public static function load() |
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84 | } |
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Adding a
@return
annotation to a constructor is not recommended, since a constructor does not have a meaningful return value.Please refer to the PHP core documentation on constructors.