Complex classes like WhereStatement 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 WhereStatement, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 15 | class WhereStatement extends Statement |
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| 16 | { |
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| 17 | /** |
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| 18 | * @var bool |
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| 19 | */ |
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| 20 | protected $having; |
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| 21 | |||
| 22 | /** |
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| 23 | * @var array |
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| 24 | */ |
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| 25 | protected $conditions = []; |
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| 26 | |||
| 27 | /** |
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| 28 | * @param bool $having when true, statement becomes a having statement |
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| 29 | */ |
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| 30 | public function __construct($having = false) |
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| 34 | |||
| 35 | /** |
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| 36 | * Tells whether this statement is a HAVING statement. |
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| 37 | * |
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| 38 | * @return bool true: is HAVING, false: is WHERE |
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| 39 | */ |
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| 40 | public function isHaving() |
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| 44 | |||
| 45 | /** |
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| 46 | * Adds a condition to the statement. |
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| 47 | * |
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| 48 | * Accepts the following forms: |
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| 49 | * 1. Equality comparison: |
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| 50 | * addCondition('username', 'john') |
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| 51 | * 2. Comparison with custom operator: |
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| 52 | * addCondition('balance', 100, '>') |
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| 53 | * 3. IN statement: |
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| 54 | * addCondition('group', ['admin', 'owner']) |
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| 55 | * 4. SQL fragment: |
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| 56 | * addCondition('name LIKE "%john%"') |
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| 57 | * 5. Subquery: |
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| 58 | * addCondition(function(SelectQuery $query) {}) |
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| 59 | * 6. List of conditions to add: |
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| 60 | * addCondition([['balance', 100, '>'], |
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| 61 | * ['user_id', 5]]) |
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| 62 | * 7. Map of equality comparisons: |
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| 63 | * addCondition(['username' => 'john', |
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| 64 | * 'user_id' => 5]) |
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| 65 | * 8. List of SQL fragments: |
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| 66 | * addCondition(['first_name LIKE "%john%"', |
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| 67 | * 'last_name LIKE "%doe%"']) |
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| 68 | * |
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| 69 | * @param array|string $field |
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| 70 | * @param string|bool $value condition value (optional) |
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| 71 | * @param string $operator operator (optional) |
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| 72 | * |
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| 73 | * @return self |
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| 74 | */ |
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| 75 | public function addCondition($field, $value = false, $operator = '=') |
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| 76 | { |
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| 77 | if (is_array($field) && !$value) { |
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| 78 | foreach ($field as $key => $value) { |
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| 79 | // handles #6 |
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| 80 | if (is_array($value)) { |
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| 81 | call_user_func_array([$this, 'addCondition'], $value); |
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| 82 | // handles #7 |
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| 83 | } elseif (!is_numeric($key)) { |
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| 84 | $this->addCondition($key, $value); |
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| 85 | // handles #8 |
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| 86 | } else { |
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| 87 | $this->addCondition($value); |
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| 88 | } |
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| 89 | } |
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| 90 | |||
| 91 | return $this; |
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| 92 | } |
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| 93 | |||
| 94 | // handles #4 and #5 |
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| 95 | $condition = [$field]; |
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| 96 | |||
| 97 | if (func_num_args() >= 2) { |
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| 98 | // handles #3 |
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| 99 | // todo |
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| 100 | |||
| 101 | // handles #1 and #2 |
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| 102 | $condition[] = $operator; |
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| 103 | $condition[] = $value; |
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| 104 | } |
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| 105 | |||
| 106 | $this->conditions[] = $condition; |
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| 107 | |||
| 108 | return $this; |
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| 109 | } |
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| 110 | |||
| 111 | /** |
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| 112 | * Adds an OR condition. Uses same arguments as |
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| 113 | * adding AND conditions. |
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| 114 | * |
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| 115 | * @return self |
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| 116 | */ |
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| 117 | public function addOrCondition() |
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| 118 | { |
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| 119 | $this->conditions[] = ['OR']; |
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| 120 | |||
| 121 | return call_user_func_array([$this, 'addCondition'], func_get_args()); |
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| 122 | } |
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| 123 | |||
| 124 | /** |
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| 125 | * Adds a between condition to the query. |
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| 126 | * |
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| 127 | * @param string $field |
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| 128 | * @param mixed $a first between value |
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| 129 | * @param mixed $b second between value |
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| 130 | * |
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| 131 | * @return self |
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| 132 | */ |
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| 133 | public function addBetweenCondition($field, $a, $b) |
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| 134 | { |
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| 135 | $this->conditions[] = ['BETWEEN', $field, $a, $b, true]; |
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| 136 | |||
| 137 | return $this; |
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| 138 | } |
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| 139 | |||
| 140 | /** |
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| 141 | * Adds a not between condition to the query. |
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| 142 | * |
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| 143 | * @param string $field |
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| 144 | * @param mixed $a first between value |
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| 145 | * @param mixed $b second between value |
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| 146 | * |
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| 147 | * @return self |
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| 148 | */ |
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| 149 | public function addNotBetweenCondition($field, $a, $b) |
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| 150 | { |
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| 151 | $this->conditions[] = ['BETWEEN', $field, $a, $b, false]; |
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| 152 | |||
| 153 | return $this; |
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| 154 | } |
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| 155 | |||
| 156 | /** |
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| 157 | * Adds an exists condition to the query. |
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| 158 | * |
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| 159 | * @param callable $f |
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| 160 | * |
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| 161 | * @return self |
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| 162 | */ |
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| 163 | public function addExistsCondition(callable $f) |
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| 164 | { |
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| 165 | $this->conditions[] = ['EXISTS', $f, true]; |
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| 166 | |||
| 167 | return $this; |
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| 168 | } |
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| 169 | |||
| 170 | /** |
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| 171 | * Adds a not exists condition to the query. |
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| 172 | * |
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| 173 | * @param callable $f |
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| 174 | * |
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| 175 | * @return self |
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| 176 | */ |
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| 177 | public function addNotExistsCondition(callable $f) |
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| 178 | { |
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| 179 | $this->conditions[] = ['EXISTS', $f, false]; |
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| 180 | |||
| 181 | return $this; |
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| 182 | } |
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| 183 | |||
| 184 | /** |
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| 185 | * Gets the conditions for this statement. |
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| 186 | * |
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| 187 | * @return array |
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| 188 | */ |
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| 189 | public function getConditions() |
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| 190 | { |
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| 191 | return $this->conditions; |
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| 192 | } |
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| 193 | |||
| 194 | public function build() |
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| 195 | { |
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| 196 | // reset the parameterized values |
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| 197 | $this->values = []; |
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| 198 | |||
| 199 | // build clause from conditions |
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| 200 | $clauses = []; |
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| 201 | foreach ($this->conditions as $condition) { |
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| 202 | $clauses[] = $this->buildClause($condition); |
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| 203 | } |
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| 204 | |||
| 205 | // remove empty values |
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| 206 | $clauses = array_filter($clauses); |
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| 207 | |||
| 208 | if (count($clauses) == 0) { |
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| 209 | return ''; |
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| 210 | } |
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| 211 | |||
| 212 | return ((!$this->having) ? 'WHERE ' : 'HAVING ').$this->implodeClauses($clauses); |
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| 213 | } |
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| 214 | |||
| 215 | /** |
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| 216 | * Builds a parameterized and escaped SQL fragment |
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| 217 | * for a condition that uses our own internal |
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| 218 | * representation. |
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| 219 | * |
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| 220 | * A condition is represented by an array, and can be |
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| 221 | * have one of the following forms: |
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| 222 | * 1. ['SQL fragment'] |
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| 223 | * 2. ['identifier', '=', 'value'] |
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| 224 | * 3. ['BETWEEN', 'identifier', 'value', 'value', true] |
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| 225 | * 4. ['EXISTS', function(SelectQuery $query) {}, true] |
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| 226 | * 5. [function(SelectQuery $query) {}] |
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| 227 | * 6. [function(SelectQuery $query) {}, '=', 'value'] |
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| 228 | * |
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| 229 | * @param array $cond |
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| 230 | * |
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| 231 | * @return string generated SQL fragment |
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| 232 | */ |
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| 233 | protected function buildClause(array $cond) |
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| 234 | { |
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| 235 | // handle SQL fragments |
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| 236 | if (count($cond) == 1 && (is_string($cond[0]) || !is_callable($cond[0]))) { |
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| 237 | return $cond[0]; |
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| 238 | } |
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| 239 | |||
| 240 | // handle EXISTS conditions |
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| 241 | if ($cond[0] === 'EXISTS') { |
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| 242 | return $this->buildExists($cond[1], $cond[2]); |
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| 243 | } |
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| 244 | |||
| 245 | // handle BETWEEN conditions |
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| 246 | if ($cond[0] === 'BETWEEN') { |
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| 247 | return $this->buildBetween($cond[1], $cond[2], $cond[3], $cond[4]); |
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| 248 | } |
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| 249 | |||
| 250 | // escape an identifier |
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| 251 | if (is_string($cond[0]) || !is_callable($cond[0])) { |
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| 252 | $cond[0] = $this->escapeIdentifier($cond[0]); |
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| 253 | |||
| 254 | // handle a subquery |
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| 255 | // NOTE string callables are not supported |
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| 256 | // as subquery functions |
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| 257 | } elseif (is_callable($cond[0])) { |
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| 258 | $cond[0] = $this->buildSubquery($cond[0]); |
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| 259 | } |
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| 260 | |||
| 261 | if (count($cond) === 1 || empty($cond[0])) { |
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| 262 | return $cond[0]; |
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| 263 | } |
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| 264 | |||
| 265 | // handle NULL values |
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| 266 | if ($cond[2] === null && in_array($cond[1], ['=', '<>'])) { |
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| 267 | return $this->buildNull($cond[0], $cond[1] == '='); |
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| 268 | } |
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| 269 | |||
| 270 | // handle IN values |
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| 271 | if (is_array($cond[2]) && in_array($cond[1], ['=', '<>'])) { |
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| 272 | return $this->buildIn($cond[0], $cond[2], $cond[1] == '='); |
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| 273 | } |
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| 274 | |||
| 275 | // otherwise parameterize the value |
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| 276 | $cond[2] = $this->parameterize($cond[2]); |
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| 277 | |||
| 278 | return implode(' ', $cond); |
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| 279 | } |
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| 280 | |||
| 281 | /** |
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| 282 | * Builds a subquery. |
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| 283 | * |
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| 284 | * @param callable $f |
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| 285 | * |
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| 286 | * @return string |
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| 287 | */ |
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| 288 | protected function buildSubquery(callable $f) |
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| 298 | |||
| 299 | /** |
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| 300 | * Builds an EXISTS clause. |
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| 301 | * |
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| 302 | * @param callable $f |
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| 303 | * @param bool $isExists |
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| 304 | * |
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| 305 | * @return string |
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| 306 | */ |
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| 307 | protected function buildExists(callable $f, $isExists) |
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| 313 | |||
| 314 | /** |
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| 315 | * Builds a BETWEEN clause. |
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| 316 | * |
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| 317 | * @param string $field |
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| 318 | * @param mixed $value1 |
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| 319 | * @param mixed $value2 |
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| 320 | * @param bool $isBetween |
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| 321 | * |
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| 322 | * @return string |
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| 323 | */ |
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| 324 | protected function buildBetween($field, $value1, $value2, $isBetween) |
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| 325 | { |
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| 326 | $operator = $isBetween ? 'BETWEEN' : 'NOT BETWEEN'; |
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| 327 | |||
| 328 | return $this->escapeIdentifier($field).' '.$operator.' '.$this->parameterize($value1).' AND '.$this->parameterize($value2); |
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| 329 | } |
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| 330 | |||
| 331 | /** |
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| 332 | * Builds a NULL clause. |
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| 333 | * |
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| 334 | * @param string $field |
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| 335 | * @param bool $isEqual |
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| 336 | * |
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| 337 | * @return string |
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| 338 | */ |
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| 339 | protected function buildNull($field, $isEqual) |
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| 345 | |||
| 346 | protected function buildIn($field, $values, $isIn) |
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| 347 | { |
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| 348 | $operator = $isIn ? ' IN ' : ' NOT IN '; |
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| 349 | |||
| 350 | return $field.$operator.$this->parameterizeValues($values); |
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| 351 | } |
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| 352 | |||
| 353 | /** |
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| 354 | * Implodes a list of WHERE clauses. |
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| 355 | * |
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| 356 | * @param array $clauses |
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| 357 | * |
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| 358 | * @return string |
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| 359 | */ |
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| 360 | protected function implodeClauses(array $clauses) |
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| 382 | } |
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| 383 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: