Complex classes like PDO 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 PDO, and based on these observations, apply Extract Interface, too.
1 | <?php |
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29 | class PDO extends BasePDO implements PDOInterface |
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30 | { |
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31 | const VERSION = '0.7.0'; |
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32 | const DRIVER_NAME = 'crate'; |
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33 | |||
34 | const DSN_REGEX = '/^(?:crate:)(?:((?:[\w\d\.-]+:\d+\,?)+))\/?([\w]+)?$/'; |
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35 | |||
36 | const CRATE_ATTR_HTTP_BASIC_AUTH = 1000; |
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37 | /** |
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38 | * deprecated since version 0.4 |
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39 | * @deprecated |
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40 | */ |
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41 | const ATTR_HTTP_BASIC_AUTH = self::CRATE_ATTR_HTTP_BASIC_AUTH; |
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42 | const CRATE_ATTR_DEFAULT_SCHEMA = 1001; |
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43 | |||
44 | const PARAM_FLOAT = 6; |
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45 | const PARAM_DOUBLE = 7; |
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46 | const PARAM_LONG = 8; |
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47 | const PARAM_ARRAY = 9; |
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48 | const PARAM_OBJECT = 10; |
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49 | const PARAM_TIMESTAMP = 11; |
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50 | const PARAM_IP = 12; |
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51 | |||
52 | /** |
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53 | * @var array |
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54 | */ |
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55 | private $attributes = [ |
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56 | 'defaultFetchMode' => self::FETCH_BOTH, |
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57 | 'errorMode' => self::ERRMODE_SILENT, |
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58 | 'statementClass' => 'Crate\PDO\PDOStatement', |
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59 | 'timeout' => 5.0, |
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60 | 'auth' => [], |
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61 | 'defaultSchema' => 'doc' |
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62 | ]; |
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63 | |||
64 | /** |
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65 | * @var Http\ClientInterface |
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66 | */ |
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67 | private $client; |
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68 | |||
69 | /** |
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70 | * @var PDOStatement|null |
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71 | */ |
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72 | private $lastStatement; |
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73 | |||
74 | /** |
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75 | * @var callable |
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76 | */ |
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77 | private $request; |
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78 | |||
79 | /** |
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80 | * {@inheritDoc} |
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81 | * |
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82 | * @param string $dsn The HTTP endpoint to call |
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83 | * @param null $username Unused |
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84 | * @param null $passwd Unused |
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85 | * @param null|array $options Attributes to set on the PDO |
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86 | */ |
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87 | 4 | public function __construct($dsn, $username, $passwd, $options) |
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88 | { |
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89 | 4 | foreach (ArrayUtils::toArray($options) as $attribute => $value) { |
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90 | 1 | $this->setAttribute($attribute, $value); |
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91 | 4 | } |
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92 | |||
93 | 4 | $dsnParts = self::parseDSN($dsn); |
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94 | 4 | $servers = self::serversFromDsnParts($dsnParts); |
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95 | |||
96 | 4 | $this->client = new Http\Client($servers, [ |
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97 | 4 | 'timeout' => $this->attributes['timeout'] |
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98 | 4 | ]); |
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99 | |||
100 | 4 | if (!empty($username) && !empty($passwd)) { |
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101 | 1 | $this->setAttribute(PDO::CRATE_ATTR_HTTP_BASIC_AUTH, [$username, $passwd]); |
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102 | 1 | } |
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103 | |||
104 | 4 | if (!empty($dsnParts[1])) { |
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105 | $this->setAttribute(PDO::CRATE_ATTR_DEFAULT_SCHEMA, $dsnParts[1]); |
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106 | } |
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107 | |||
108 | // Define a callback that will be used in the PDOStatements |
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109 | // This way we don't expose this as a public api to the end users. |
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110 | $this->request = function (PDOStatement $statement, $sql, array $parameters) { |
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111 | |||
112 | $this->lastStatement = $statement; |
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113 | |||
114 | try { |
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115 | |||
116 | return $this->client->execute($sql, $parameters); |
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117 | |||
118 | } catch (Exception\RuntimeException $e) { |
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119 | |||
120 | if ($this->getAttribute(PDO::ATTR_ERRMODE) === PDO::ERRMODE_EXCEPTION) { |
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121 | throw new Exception\PDOException($e->getMessage(), $e->getCode()); |
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122 | } |
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123 | |||
124 | if ($this->getAttribute(PDO::ATTR_ERRMODE) === PDO::ERRMODE_WARNING) { |
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125 | trigger_error(sprintf('[%d] %s', $e->getCode(), $e->getMessage()), E_USER_WARNING); |
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126 | } |
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127 | |||
128 | // should probably wrap this in a error object ? |
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129 | return [ |
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130 | 'code' => $e->getCode(), |
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131 | 'message' => $e->getMessage() |
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132 | ]; |
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133 | } |
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134 | }; |
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135 | 4 | } |
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136 | |||
137 | /** |
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138 | * Extract servers and optional custom schema from DSN string |
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139 | * |
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140 | * @param string $dsn The DSN string |
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141 | * |
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142 | * @return array An array of ['host:post,host:port,...', 'schema'] |
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143 | */ |
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144 | 36 | private static function parseDSN($dsn) |
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145 | { |
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146 | 36 | $matches = array(); |
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147 | |||
148 | 36 | if (!preg_match(static::DSN_REGEX, $dsn, $matches)) { |
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149 | 4 | throw new PDOException(sprintf('Invalid DSN %s', $dsn)); |
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150 | } |
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151 | |||
152 | 32 | return array_slice($matches, 1); |
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153 | } |
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154 | |||
155 | /** |
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156 | * Extract host:port pairs out of the DSN parts |
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157 | * |
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158 | * @param array $dsnParts The parts of the parsed DSN string |
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159 | * |
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160 | * @return array An array of host:port strings |
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161 | */ |
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162 | 31 | private static function serversFromDsnParts($dsnParts) |
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163 | { |
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164 | 31 | return explode(',', trim($dsnParts[0], ',')); |
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165 | } |
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166 | |||
167 | /** |
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168 | * {@inheritDoc} |
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169 | */ |
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170 | 1 | public function prepare($statement, $options = null) |
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171 | { |
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172 | 1 | $options = ArrayUtils::toArray($options); |
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173 | |||
174 | 1 | if (isset($options[PDO::ATTR_CURSOR])) { |
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175 | trigger_error(sprintf('%s not supported', __METHOD__), E_USER_WARNING); |
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176 | return true; |
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177 | } |
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178 | |||
179 | 1 | return new PDOStatement($this, $this->request, $statement, $options); |
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180 | } |
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181 | |||
182 | /** |
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183 | * {@inheritDoc} |
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184 | */ |
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185 | 1 | public function beginTransaction() |
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186 | { |
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187 | 1 | return true; |
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188 | } |
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189 | |||
190 | /** |
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191 | * {@inheritDoc} |
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192 | */ |
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193 | 1 | public function commit() |
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194 | { |
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195 | 1 | return true; |
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196 | } |
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197 | |||
198 | /** |
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199 | * {@inheritDoc} |
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200 | */ |
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201 | 1 | public function rollBack() |
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205 | |||
206 | /** |
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207 | * {@inheritDoc} |
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208 | */ |
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209 | 1 | public function inTransaction() |
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210 | { |
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211 | 1 | return false; |
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213 | |||
214 | /** |
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215 | * {@inheritDoc} |
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216 | */ |
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217 | public function exec($statement) |
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224 | |||
225 | /** |
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226 | * {@inheritDoc} |
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227 | */ |
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228 | public function query($statement) |
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235 | |||
236 | /** |
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237 | * {@inheritDoc} |
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238 | */ |
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239 | 1 | public function lastInsertId($name = null) |
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243 | |||
244 | /** |
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245 | * {@inheritDoc} |
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246 | */ |
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247 | public function errorCode() |
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251 | |||
252 | /** |
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253 | * {@inheritDoc} |
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254 | */ |
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255 | public function errorInfo() |
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259 | |||
260 | /** |
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261 | * {@inheritDoc} |
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262 | */ |
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263 | 6 | public function setAttribute($attribute, $value) |
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300 | |||
301 | /** |
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302 | * {@inheritDoc} |
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303 | */ |
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304 | 9 | public function getAttribute($attribute) |
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352 | |||
353 | /** |
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354 | * {@inheritDoc} |
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355 | */ |
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356 | 4 | public function quote($string, $parameter_type = PDO::PARAM_STR) |
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378 | |||
379 | /** |
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380 | * {@inheritDoc} |
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381 | */ |
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382 | 1 | public static function getAvailableDrivers() |
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386 | |||
387 | public function getServerVersion() |
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393 | |||
394 | public function getServerInfo() |
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398 | } |
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399 |