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 AbstractHandler 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 AbstractHandler, and based on these observations, apply Extract Interface, too.
1 | <?php |
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25 | abstract class AbstractHandler |
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26 | { |
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27 | /** |
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28 | * Behaviours. |
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29 | */ |
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30 | const DROP_FOREIGNS = 0b000000001; |
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31 | const CREATE_FOREIGNS = 0b000000010; |
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32 | const ALTER_FOREIGNS = 0b000000100; |
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33 | |||
34 | //All foreign keys related operations |
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35 | const DO_FOREIGNS = self::DROP_FOREIGNS | self::ALTER_FOREIGNS | self::CREATE_FOREIGNS; |
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36 | |||
37 | const DROP_COLUMNS = 0b000001000; |
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38 | const CREATE_COLUMNS = 0b000010000; |
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39 | const ALTER_COLUMNS = 0b000100000; |
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40 | |||
41 | //All columns related operations |
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42 | const DO_COLUMNS = self::DROP_COLUMNS | self::ALTER_COLUMNS | self::CREATE_COLUMNS; |
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43 | |||
44 | const DROP_INDEXES = 0b001000000; |
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45 | const CREATE_INDEXES = 0b010000000; |
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46 | const ALTER_INDEXES = 0b100000000; |
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47 | |||
48 | //All index related operations |
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49 | const DO_INDEXES = self::DROP_INDEXES | self::ALTER_INDEXES | self::CREATE_INDEXES; |
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50 | |||
51 | //Schema operations |
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52 | const DO_RENAME = 0b10000000000; |
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53 | const DO_DROP = 0b01000000000; |
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54 | |||
55 | //All operations |
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56 | const DO_ALL = self::DO_FOREIGNS | self::DO_INDEXES | self::DO_COLUMNS | self::DO_DROP | self::DO_RENAME; |
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57 | |||
58 | /** |
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59 | * @var LoggerInterface|null |
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60 | */ |
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61 | private $logger = null; |
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62 | |||
63 | /** |
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64 | * @var Driver |
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65 | */ |
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66 | protected $driver; |
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67 | |||
68 | /** |
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69 | * @param Driver $driver |
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70 | * @param LoggerInterface|null $logger |
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71 | */ |
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72 | public function __construct(Driver $driver, LoggerInterface $logger = null) |
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73 | { |
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74 | $this->driver = $driver; |
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75 | $this->logger = $logger; |
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76 | } |
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77 | |||
78 | /** |
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79 | * Associated driver. |
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80 | * |
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81 | * @return Driver |
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82 | */ |
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83 | public function getDriver(): Driver |
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84 | { |
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85 | return $this->driver; |
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86 | } |
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87 | |||
88 | /** |
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89 | * Create table based on a given schema. |
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90 | * |
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91 | * @param AbstractTable $table |
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92 | * |
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93 | * @throws HandlerException |
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94 | */ |
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95 | public function createTable(AbstractTable $table) |
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96 | { |
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97 | $this->log("Creating new table '{table}'.", ['table' => $table->getName()]); |
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98 | |||
99 | //Executing! |
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100 | $this->run($this->createStatement($table)); |
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101 | |||
102 | //Not all databases support adding index while table creation, so we can do it after |
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103 | foreach ($table->getIndexes() as $index) { |
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104 | $this->createIndex($table, $index); |
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105 | } |
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106 | } |
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107 | |||
108 | /** |
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109 | * Drop table from database. |
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110 | * |
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111 | * @param AbstractTable $table |
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112 | * |
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113 | * @throws HandlerException |
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114 | */ |
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115 | public function dropTable(AbstractTable $table) |
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116 | { |
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117 | $this->log("Dropping table '{table}'.", ['table' => $table->getName()]); |
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118 | $this->run("DROP TABLE {$this->identify($table->getInitialName())}"); |
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119 | } |
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120 | |||
121 | /** |
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122 | * Sync given table schema. |
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123 | * |
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124 | * @param AbstractTable $table |
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125 | * @param int $behaviour See behaviour constants. |
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126 | */ |
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127 | public function syncTable(AbstractTable $table, int $behaviour = self::DO_ALL) |
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128 | { |
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129 | $comparator = $table->getComparator(); |
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130 | |||
131 | if ($comparator->isRenamed() && $behaviour & self::DO_RENAME) { |
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132 | $this->log('Renaming table {table} to {name}.', [ |
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133 | 'table' => $this->identify($table->getInitialName()), |
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134 | 'name' => $this->identify($table->getName()) |
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135 | ]); |
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136 | |||
137 | //Executing renaming |
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138 | $this->renameTable($table->getInitialName(), $table->getName()); |
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139 | } |
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140 | |||
141 | /* |
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142 | * This is schema synchronization code, if you are reading it you are either experiencing |
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143 | * VERY weird bug, or you are very curious. Please contact me in a any scenario :) |
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144 | */ |
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145 | if ($behaviour & self::DROP_FOREIGNS) { |
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146 | $this->dropForeigns($table, $comparator); |
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147 | } |
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148 | |||
149 | if ($behaviour & self::DROP_INDEXES) { |
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150 | $this->dropIndexes($table, $comparator); |
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151 | } |
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152 | |||
153 | if ($behaviour & self::DROP_COLUMNS) { |
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154 | $this->dropColumns($table, $comparator); |
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155 | } |
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156 | |||
157 | if ($behaviour & self::CREATE_COLUMNS) { |
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158 | $this->createColumns($table, $comparator); |
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159 | } |
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160 | |||
161 | if ($behaviour & self::ALTER_COLUMNS) { |
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162 | $this->alterColumns($table, $comparator); |
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163 | } |
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164 | |||
165 | if ($behaviour & self::CREATE_INDEXES) { |
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166 | $this->createIndexes($table, $comparator); |
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167 | } |
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168 | |||
169 | if ($behaviour & self::ALTER_INDEXES) { |
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170 | $this->alterIndexes($table, $comparator); |
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171 | } |
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172 | |||
173 | if ($behaviour & self::CREATE_FOREIGNS) { |
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174 | $this->createForeigns($table, $comparator); |
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175 | } |
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176 | |||
177 | if ($behaviour & self::ALTER_FOREIGNS) { |
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178 | $this->alterForeigns($table, $comparator); |
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179 | } |
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180 | } |
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181 | |||
182 | /** |
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183 | * Rename table from one name to another. |
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184 | * |
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185 | * @param string $table |
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186 | * @param string $name |
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187 | * |
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188 | * @throws HandlerException |
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189 | */ |
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190 | public function renameTable(string $table, string $name) |
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194 | |||
195 | /** |
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196 | * Driver specific column add command. |
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197 | * |
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198 | * @param AbstractTable $table |
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199 | * @param AbstractColumn $column |
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200 | * |
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201 | * @throws HandlerException |
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202 | */ |
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203 | public function createColumn(AbstractTable $table, AbstractColumn $column) |
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207 | |||
208 | /** |
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209 | * Driver specific column remove (drop) command. |
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210 | * |
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211 | * @param AbstractTable $table |
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212 | * @param AbstractColumn $column |
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213 | * |
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214 | * @return self |
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215 | */ |
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216 | public function dropColumn(AbstractTable $table, AbstractColumn $column) |
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225 | |||
226 | /** |
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227 | * Driver specific column alter command. |
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228 | * |
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229 | * @param AbstractTable $table |
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230 | * @param AbstractColumn $initial |
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231 | * @param AbstractColumn $column |
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232 | * |
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233 | * @throws HandlerException |
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234 | */ |
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235 | abstract public function alterColumn( |
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240 | |||
241 | /** |
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242 | * Driver specific index adding command. |
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243 | * |
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244 | * @param AbstractTable $table |
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245 | * @param AbstractIndex $index |
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246 | * |
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247 | * @throws HandlerException |
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248 | */ |
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249 | public function createIndex(AbstractTable $table, AbstractIndex $index) |
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253 | |||
254 | /** |
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255 | * Driver specific index remove (drop) command. |
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256 | * |
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257 | * @param AbstractTable $table |
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258 | * @param AbstractIndex $index |
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259 | * |
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260 | * @throws HandlerException |
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261 | */ |
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262 | public function dropIndex(AbstractTable $table, AbstractIndex $index) |
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266 | |||
267 | /** |
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268 | * Driver specific index alter command, by default it will remove and add index. |
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269 | * |
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270 | * @param AbstractTable $table |
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271 | * @param AbstractIndex $initial |
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272 | * @param AbstractIndex $index |
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273 | * |
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274 | * @throws HandlerException |
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275 | */ |
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276 | public function alterIndex(AbstractTable $table, AbstractIndex $initial, AbstractIndex $index) |
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281 | |||
282 | /** |
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283 | * Driver specific foreign key adding command. |
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284 | * |
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285 | * @param AbstractTable $table |
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286 | * @param AbstractReference $foreign |
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287 | * |
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288 | * @throws HandlerException |
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289 | */ |
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290 | public function createForeign(AbstractTable $table, AbstractReference $foreign) |
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294 | |||
295 | /** |
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296 | * Driver specific foreign key remove (drop) command. |
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297 | * |
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298 | * @param AbstractTable $table |
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299 | * @param AbstractReference $foreign |
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300 | * |
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301 | * @throws HandlerException |
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302 | */ |
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303 | public function dropForeign(AbstractTable $table, AbstractReference $foreign) |
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307 | |||
308 | /** |
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309 | * Driver specific foreign key alter command, by default it will remove and add foreign key. |
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310 | * |
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311 | * @param AbstractTable $table |
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312 | * @param AbstractReference $initial |
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313 | * @param AbstractReference $foreign |
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314 | * |
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315 | * @throws HandlerException |
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316 | */ |
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317 | public function alterForeign( |
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325 | |||
326 | /** |
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327 | * Drop column constraint using it's name. |
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328 | * |
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329 | * @param AbstractTable $table |
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330 | * @param string $constraint |
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331 | * |
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332 | * @throws HandlerException |
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333 | */ |
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334 | public function dropConstrain(AbstractTable $table, $constraint) |
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338 | |||
339 | /** |
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340 | * Get statement needed to create table. Indexes will be created separately. |
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341 | * |
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342 | * @param AbstractTable $table |
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343 | * |
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344 | * @return string |
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345 | */ |
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346 | protected function createStatement(AbstractTable $table) |
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374 | |||
375 | /** |
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376 | * Execute statement. |
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377 | * |
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378 | * @param string $statement |
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379 | * @param array $parameters |
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380 | * |
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381 | * @return \PDOStatement |
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382 | * |
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383 | * @throws HandlerException |
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384 | */ |
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385 | protected function run(string $statement, array $parameters = []): \PDOStatement |
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393 | |||
394 | /** |
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395 | * Helper function, saves log message into logger if any attached. |
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396 | * |
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397 | * @param string $message |
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398 | * @param array $context |
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399 | */ |
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400 | protected function log(string $message, array $context = []) |
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406 | |||
407 | /** |
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408 | * Create element identifier. |
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409 | * |
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410 | * @param AbstractElement|AbstractTable|string $element |
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411 | * |
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412 | * @return string |
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413 | */ |
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414 | protected function identify($element) |
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426 | |||
427 | /** |
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428 | * @param AbstractTable $table |
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429 | * @param StateComparator $comparator |
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430 | */ |
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431 | View Code Duplication | protected function alterForeigns(AbstractTable $table, StateComparator $comparator) |
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448 | |||
449 | /** |
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450 | * @param AbstractTable $table |
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451 | * @param StateComparator $comparator |
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452 | */ |
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453 | View Code Duplication | protected function createForeigns(AbstractTable $table, StateComparator $comparator) |
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464 | |||
465 | /** |
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466 | * @param AbstractTable $table |
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467 | * @param StateComparator $comparator |
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468 | */ |
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469 | View Code Duplication | protected function alterIndexes(AbstractTable $table, StateComparator $comparator) |
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487 | |||
488 | /** |
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489 | * @param AbstractTable $table |
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490 | * @param StateComparator $comparator |
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491 | */ |
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492 | View Code Duplication | protected function createIndexes(AbstractTable $table, StateComparator $comparator) |
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503 | |||
504 | /** |
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505 | * @param AbstractTable $table |
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506 | * @param StateComparator $comparator |
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507 | */ |
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508 | View Code Duplication | protected function alterColumns(AbstractTable $table, StateComparator $comparator) |
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527 | |||
528 | /** |
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529 | * @param AbstractTable $table |
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530 | * @param StateComparator $comparator |
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531 | */ |
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532 | View Code Duplication | protected function createColumns(AbstractTable $table, StateComparator $comparator) |
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544 | |||
545 | /** |
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546 | * @param AbstractTable $table |
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547 | * @param StateComparator $comparator |
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548 | */ |
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549 | View Code Duplication | protected function dropColumns(AbstractTable $table, StateComparator $comparator) |
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560 | |||
561 | /** |
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562 | * @param AbstractTable $table |
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563 | * @param StateComparator $comparator |
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564 | */ |
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565 | View Code Duplication | protected function dropIndexes(AbstractTable $table, StateComparator $comparator) |
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576 | |||
577 | /** |
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578 | * @param AbstractTable $table |
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579 | * @param StateComparator $comparator |
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580 | */ |
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581 | View Code Duplication | protected function dropForeigns(AbstractTable $table, $comparator) |
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592 | |||
593 | /** |
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594 | * Applied to every column in order to make sure that driver support it. |
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595 | * |
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596 | * @param AbstractColumn $column |
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597 | * |
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598 | * @throws DriverException |
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599 | */ |
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600 | protected function assertValid(AbstractColumn $column) |
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604 | } |
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.