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 MySQLiDriver 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 MySQLiDriver, and based on these observations, apply Extract Interface, too.
1 | <?php |
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29 | class MySQLiDriver extends DBBaseDriver implements DBDriverInterface{ |
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30 | |||
31 | /** |
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32 | * Holds the database resource object |
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33 | * |
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34 | * @var mysqli |
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35 | */ |
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36 | protected $db; |
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37 | |||
38 | /** |
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39 | * Establishes a database connection and returns the connection object |
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40 | * |
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41 | * @return mysqli the database resource object |
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42 | * @throws DBException |
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43 | */ |
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44 | public function connect(){ |
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86 | |||
87 | /** |
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88 | * Closes a database connection |
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89 | * |
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90 | * @return $this |
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91 | */ |
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92 | public function disconnect(){ |
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95 | |||
96 | /** |
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97 | * Returns info about the used php client |
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98 | * |
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99 | * @return string php's database client string |
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100 | */ |
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101 | public function getClientInfo(){ |
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104 | |||
105 | /** |
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106 | * Returns info about the database server |
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107 | * |
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108 | * @return string database's serverinfo string |
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109 | */ |
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110 | public function getServerInfo(){ |
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113 | |||
114 | /** |
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115 | * Sanitizer. |
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116 | * |
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117 | * Recursively escapes string values, optional htmlspecialchars() |
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118 | * |
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119 | * @param array|string $data array or string to escape |
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120 | * @param bool $specialchars [optional] if true, it performs a htmlspecialchars() on each value given |
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121 | * |
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122 | * @return array|string array or string. escaped. obviously. |
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123 | */ |
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124 | View Code Duplication | public function escape($data, $specialchars = false){ |
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151 | |||
152 | /** |
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153 | * Basic SQL query for non prepared statements |
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154 | * |
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155 | * There is no escaping in here, so make sure, your SQL is clean/escaped. |
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156 | * Also, your SQL should NEVER contain user input, use prepared statements in this case. |
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157 | * |
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158 | * If the query was successful it returns either an array of results or true |
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159 | * if it was a void query. On errors, a false will be returned, obviously. |
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160 | * |
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161 | * @param string $sql The SQL statement |
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162 | * @param string $index [optional] an index column to assingn as the result's keys |
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163 | * @param bool $assoc [optional] If true, the fields are named with the respective column names, otherwise numbered |
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164 | * @param bool $fetch_array [optional] fetch the vaues as array instead of object |
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165 | * |
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166 | * @return array|bool array with results, true on void query success, otherwise false. |
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167 | * @throws \chillerlan\Database\DBException |
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168 | */ |
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169 | public function raw($sql, $index = '', $assoc = true, $fetch_array = false){ |
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219 | |||
220 | /** |
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221 | * Prepared statements wrapper |
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222 | * |
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223 | * Does everything for you: prepares the statement and fetches the results as an object or array |
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224 | * just pass a query along with values and you're done. Not meant for multi-inserts. |
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225 | * |
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226 | * @param string $sql The SQL statement to prepare |
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227 | * @param array $values [optional] the value for each "?" in the statement - in the respective order, of course |
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228 | * @param string $index [optional] an index column to assingn as the result's keys |
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229 | * @param bool $assoc [optional] If true, the fields are named with the respective column names, otherwise numbered |
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230 | * @param bool $fetch_array [optional] fetch the vaues as array instead of object |
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231 | * |
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232 | * @return array|bool Array with results, true on void query success, otherwise false |
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233 | * @throws \chillerlan\Database\DBException |
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234 | */ |
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235 | public function prepared($sql, array $values = [], $index = '', $assoc = true, $fetch_array = false){ |
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274 | |||
275 | /** |
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276 | * Prepared multi line insert |
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277 | * |
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278 | * Prepared statement multi insert/update |
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279 | * |
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280 | * @param string $sql The SQL statement to prepare |
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281 | * @param array $values a multidimensional array with the values, each row represents one line to insert. |
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282 | * |
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283 | * @return bool true query success, otherwise false |
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284 | * @throws \chillerlan\Database\DBException |
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285 | */ |
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286 | public function multi($sql, array $values){ |
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307 | |||
308 | /** |
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309 | * Prepared multi line insert/update with callback |
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310 | * @see https://gist.github.com/krakjoe/6437782 |
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311 | * @see https://gist.github.com/krakjoe/9384409 |
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312 | * |
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313 | * @param string $sql The SQL statement to prepare |
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314 | * @param array $data an array with the (raw) data to insert, each row represents one line to insert. |
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315 | * @param callable|array $callback a callback that processes the values for each row. |
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316 | * |
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317 | * @return bool true query success, otherwise false |
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318 | * @throws \chillerlan\Database\DBException |
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319 | */ |
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320 | public function multi_callback($sql, array $data, $callback){ |
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348 | |||
349 | /** |
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350 | * @param \mysqli_stmt $stmt |
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351 | * @param \ReflectionMethod $reflectionMethod |
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352 | * @param array $row |
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353 | */ |
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354 | protected function insertPreparedRow(mysqli_stmt &$stmt, ReflectionMethod &$reflectionMethod, array &$row){ |
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360 | |||
361 | /** |
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362 | * @param \mysqli_stmt $stmt |
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363 | * @param \mysqli_result $result |
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364 | * @param bool $assoc |
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365 | * @param bool $fetch_array |
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366 | * |
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367 | * @return array|bool |
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368 | */ |
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369 | protected function getResult(mysqli_stmt &$stmt, mysqli_result &$result, $assoc, $fetch_array){ |
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408 | |||
409 | /** |
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410 | * Returns a string of types for the given values |
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411 | * |
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412 | * @link http://php.net/manual/mysqli-stmt.bind-param.php |
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413 | * |
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414 | * @param array $values |
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415 | * |
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416 | * @return string |
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417 | * @internal |
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418 | */ |
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419 | protected function getTypes(array &$values){ |
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432 | |||
433 | /** |
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434 | * Copies an array to an array of referenced values |
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435 | * |
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436 | * @param array $row |
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437 | * |
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438 | * @return array |
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439 | * @see http://php.net/manual/mysqli-stmt.bind-param.php |
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440 | */ |
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441 | protected function getReferences(array &$row){ |
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450 | |||
451 | } |
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452 |
Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property.
Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property..