Complex classes like Db 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 Db, and based on these observations, apply Extract Interface, too.
1 | <?php |
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22 | class Db |
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23 | { |
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24 | /** |
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25 | * Database handle/connection. |
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26 | * |
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27 | * @var PDO |
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28 | */ |
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29 | protected $pdo; |
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30 | |||
31 | /** |
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32 | * @var string |
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33 | */ |
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34 | protected $dsn; |
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35 | |||
36 | /** |
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37 | * @var string |
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38 | */ |
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39 | protected $username; |
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40 | |||
41 | /** |
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42 | * @var string |
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43 | */ |
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44 | protected $password; |
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45 | |||
46 | /** |
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47 | * @var array |
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48 | */ |
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49 | protected $options; |
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50 | |||
51 | /** |
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52 | * @var bool |
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53 | */ |
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54 | protected $hasActiveTransaction = false; |
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55 | |||
56 | /** |
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57 | * @var PdoFactoryInterface |
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58 | */ |
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59 | private $pdoFactory; |
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60 | |||
61 | /** |
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62 | * Constructor. |
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63 | * |
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64 | * @param string|PDO $hostDsnOrPdo A MySQL host, a dsn or an existing PDO instance. |
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65 | * @param string|null $username |
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66 | * @param string|null $password |
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67 | * @param string|null $database |
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68 | * @param array $options |
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69 | * @param PdoFactoryInterface $pdoFactory |
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70 | * |
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71 | * @deprecated The signature of the constructor will change in version 1.0.0 and accept |
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72 | * only a PDO dsn string as first parameter dropping support to inject a PDO instance or host string |
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73 | */ |
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74 | 28 | public function __construct( |
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75 | $hostDsnOrPdo, |
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76 | $username = null, |
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77 | $password = null, |
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78 | $database = null, |
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79 | array $options = [], |
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80 | PdoFactoryInterface $pdoFactory = null |
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81 | ) { |
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82 | 28 | if ($hostDsnOrPdo instanceof PDO) { |
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83 | 28 | @trigger_error( |
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84 | 'Support to pass a PDO instance to the constructor is deprecated and will be removed in version 1.0.0.' |
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85 | 28 | . ' You need to pass in a PDO dsn in the future as first parameter.', |
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86 | 28 | E_USER_DEPRECATED |
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87 | ); |
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88 | |||
89 | 28 | $this->pdo = $hostDsnOrPdo; |
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90 | 4 | } elseif (strpos($hostDsnOrPdo, ':') !== false) { |
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91 | 3 | $this->dsn = $hostDsnOrPdo; |
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92 | } else { |
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93 | 1 | @trigger_error( |
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94 | 'Support to pass a host and database to the constructor is deprecated and will be removed in version ' |
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95 | 1 | . '1.0.0. You need to pass in a PDO dsn in the future as first parameter.', |
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96 | 1 | E_USER_DEPRECATED |
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97 | ); |
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98 | 1 | $this->dsn = "mysql:host={$hostDsnOrPdo}" . ($database ? ";dbname={$database}" : ''); |
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99 | } |
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100 | |||
101 | 28 | $this->username = $username; |
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102 | 28 | $this->password = $password; |
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103 | 28 | $this->options = $options; |
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104 | 28 | $this->pdoFactory = $pdoFactory ?? new PdoFactory(); |
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105 | 28 | } |
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106 | |||
107 | 18 | public function connect() |
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108 | { |
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109 | 18 | if ($this->isConnected()) { |
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110 | 15 | return; |
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111 | } |
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112 | |||
113 | 3 | $retries = $this->options['connectRetries'] ?? 0; |
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114 | do { |
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115 | try { |
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116 | 3 | $this->pdo = $this->pdoFactory->createPdo($this->dsn, $this->username, $this->password, $this->options); |
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117 | |||
118 | 2 | return; |
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119 | 2 | } catch (PDOException $e) { |
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120 | 2 | if ($this->isConnectionExceptionCausedByConnection($e) && $retries > 0) { |
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121 | // Sleep for 100 - 500 ms until next retry |
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122 | 2 | usleep(rand(100000, 500000)); |
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123 | } else { |
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124 | 1 | throw new ConnectionException($e); |
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125 | } |
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126 | } |
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127 | 2 | } while ($retries-- > 0); |
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128 | } |
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129 | |||
130 | /** |
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131 | * @param PDOException $exception |
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132 | * @return bool |
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133 | */ |
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134 | 2 | private function isConnectionExceptionCausedByConnection(PDOException $exception) |
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135 | { |
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136 | 2 | return in_array($exception->getCode(), [ |
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137 | 2 | 2002, // Can't connect to MySQL server (Socket) |
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138 | 2003, // Can't connect to MySQL server (TCP) |
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139 | 2006, // MySQL server has gone away |
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140 | 2013, // Lost connection to MySQL server during query |
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141 | ]); |
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142 | } |
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143 | |||
144 | /** |
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145 | * Close the database connection. |
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146 | */ |
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147 | 1 | public function disconnect() |
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148 | { |
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149 | 1 | $this->pdo = null; |
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150 | 1 | } |
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151 | |||
152 | /** |
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153 | */ |
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154 | 1 | public function reconnect() |
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155 | { |
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156 | 1 | $this->disconnect(); |
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157 | 1 | $this->connect(); |
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158 | 1 | } |
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159 | |||
160 | /** |
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161 | * Check if database connection is open. |
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162 | * |
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163 | * @return bool |
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164 | */ |
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165 | 19 | public function isConnected() |
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166 | { |
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167 | 19 | return ($this->pdo instanceof PDO); |
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168 | } |
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169 | |||
170 | /** |
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171 | * Returns the PDO handle. |
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172 | * |
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173 | * Can be used to gain access to any special PDO methods. |
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174 | * |
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175 | * @return PDO |
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176 | */ |
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177 | 4 | public function getPdo() |
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178 | { |
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179 | 4 | return $this->pdo; |
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180 | } |
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181 | |||
182 | /** |
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183 | * Creates and executes a PDO statement. |
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184 | * |
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185 | * @param string $sql |
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186 | * @param array $parameters |
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187 | * @return PDOStatement |
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188 | */ |
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189 | 7 | protected function executeQuery($sql, array $parameters = []) |
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190 | { |
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191 | 7 | $this->connect(); |
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192 | |||
193 | 7 | $dbParameters = $this->prepareParameters($parameters); |
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194 | try { |
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195 | 6 | $pdoStatement = $this->pdo->prepare($sql); |
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196 | 5 | $pdoStatement->execute($dbParameters); |
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197 | |||
198 | 5 | return $pdoStatement; |
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199 | 1 | } catch (PDOException $e) { |
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200 | 1 | throw new QueryException($e, $sql, $dbParameters); |
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201 | } |
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202 | } |
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203 | |||
204 | /** |
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205 | * Execute an SQL statement and return the number of affected rows. |
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206 | * |
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207 | * @param string $sql |
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208 | * @param array $parameters |
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209 | * @return int The number of rows affected |
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210 | */ |
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211 | 4 | public function exec($sql, array $parameters = []) |
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217 | |||
218 | /** |
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219 | * Execute an SQL statement and return the first row. |
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220 | * |
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221 | * @param string $sql |
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222 | * @param array $parameters |
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223 | * @param bool $indexedKeys |
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224 | * @return array|false |
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225 | */ |
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226 | 1 | public function fetchRow($sql, array $parameters = [], $indexedKeys = false) |
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232 | |||
233 | /** |
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234 | * Execute an SQL statement and return all rows as an array. |
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235 | * |
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236 | * @param string $sql |
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237 | * @param array $parameters |
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238 | * @param bool $indexedKeys |
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239 | * @return array |
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240 | */ |
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241 | 1 | public function fetchRows($sql, array $parameters = [], $indexedKeys = false) |
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247 | |||
248 | /** |
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249 | * Execute an SQL statement and return the first column of the first row. |
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250 | * |
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251 | * @param string $sql |
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252 | * @param array $parameters |
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253 | * @return string|false |
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254 | */ |
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255 | 1 | public function fetchValue($sql, array $parameters = []) |
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261 | |||
262 | /** |
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263 | * Quote a value for a safe use in query (eg. bla'bla -> 'bla''bla'). |
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264 | * |
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265 | * @param mixed $value |
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266 | * @return string |
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267 | */ |
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268 | 1 | public function quote($value) |
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274 | |||
275 | /** |
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276 | * Get id of the last inserted row. |
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277 | * |
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278 | * @return int |
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279 | */ |
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280 | 1 | public function getLastInsertId() |
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286 | |||
287 | /** |
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288 | * Prepare parameters for database use. |
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289 | * |
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290 | * @param array $parameters |
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291 | * @return array |
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292 | */ |
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293 | 7 | protected function prepareParameters(array $parameters = []) |
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310 | |||
311 | /** |
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312 | * Begin transaction (turns off autocommit mode). |
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313 | * |
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314 | * @param bool $onlyIfNoActiveTransaction |
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315 | * @return bool |
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316 | */ |
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317 | 4 | public function beginTransaction($onlyIfNoActiveTransaction = false) |
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330 | |||
331 | /** |
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332 | * Commits current active transaction (restores autocommit mode). |
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333 | */ |
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334 | 2 | public function commit() |
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341 | |||
342 | /** |
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343 | * Rolls back current active transaction (restores autocommit mode). |
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344 | */ |
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345 | 2 | public function rollBack() |
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352 | |||
353 | /** |
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354 | * @return bool |
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355 | */ |
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356 | 3 | public function hasActiveTransaction() |
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360 | |||
361 | /** |
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362 | * @param string $table |
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363 | * @param array $data |
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364 | * @param bool $updateOnDuplicateKey |
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365 | * @return int The number of rows affected |
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366 | */ |
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367 | 3 | public function insert($table, array $data, $updateOnDuplicateKey = false) |
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392 | |||
393 | /** |
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394 | * @param array $assignmentData |
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395 | * @return string |
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396 | */ |
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397 | 2 | protected function getAssignmentSql(array $assignmentData) |
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406 | |||
407 | /** |
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408 | * @param string $table |
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409 | * @param array $data |
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410 | * @param string $whereSql |
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411 | * @param array $whereParameters |
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412 | * @return int The number of rows affected |
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413 | */ |
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414 | 1 | public function update($table, array $data, $whereSql = '', array $whereParameters = []) |
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428 | } |
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429 |
If you suppress an error, we recommend checking for the error condition explicitly: