WP_Meta_Query::find_compatible_table_alias()   C
last analyzed

Complexity

Conditions 11
Paths 9

Size

Total Lines 45
Code Lines 18

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 11
eloc 18
nc 9
nop 2
dl 0
loc 45
rs 5.2653
c 0
b 0
f 0

How to fix   Complexity   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

1
<?php
2
/**
3
 * Meta API: WP_Meta_Query class
4
 *
5
 * @package WordPress
6
 * @subpackage Meta
7
 * @since 4.4.0
8
 */
9
10
/**
11
 * Core class used to implement meta queries for the Meta API.
12
 *
13
 * Used for generating SQL clauses that filter a primary query according to metadata keys and values.
14
 *
15
 * WP_Meta_Query is a helper that allows primary query classes, such as WP_Query and WP_User_Query,
16
 *
17
 * to filter their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be attached
18
 * to the primary SQL query string.
19
 *
20
 * @since 3.2.0
21
 * @package WordPress
22
 * @subpackage Meta
23
 */
24
class WP_Meta_Query {
25
	/**
26
	 * Array of metadata queries.
27
	 *
28
	 * See WP_Meta_Query::__construct() for information on meta query arguments.
29
	 *
30
	 * @since 3.2.0
31
	 * @access public
32
	 * @var array
33
	 */
34
	public $queries = array();
35
36
	/**
37
	 * The relation between the queries. Can be one of 'AND' or 'OR'.
38
	 *
39
	 * @since 3.2.0
40
	 * @access public
41
	 * @var string
42
	 */
43
	public $relation;
44
45
	/**
46
	 * Database table to query for the metadata.
47
	 *
48
	 * @since 4.1.0
49
	 * @access public
50
	 * @var string
51
	 */
52
	public $meta_table;
53
54
	/**
55
	 * Column in meta_table that represents the ID of the object the metadata belongs to.
56
	 *
57
	 * @since 4.1.0
58
	 * @access public
59
	 * @var string
60
	 */
61
	public $meta_id_column;
62
63
	/**
64
	 * Database table that where the metadata's objects are stored (eg $wpdb->users).
65
	 *
66
	 * @since 4.1.0
67
	 * @access public
68
	 * @var string
69
	 */
70
	public $primary_table;
71
72
	/**
73
	 * Column in primary_table that represents the ID of the object.
74
	 *
75
	 * @since 4.1.0
76
	 * @access public
77
	 * @var string
78
	 */
79
	public $primary_id_column;
80
81
	/**
82
	 * A flat list of table aliases used in JOIN clauses.
83
	 *
84
	 * @since 4.1.0
85
	 * @access protected
86
	 * @var array
87
	 */
88
	protected $table_aliases = array();
89
90
	/**
91
	 * A flat list of clauses, keyed by clause 'name'.
92
	 *
93
	 * @since 4.2.0
94
	 * @access protected
95
	 * @var array
96
	 */
97
	protected $clauses = array();
98
99
	/**
100
	 * Whether the query contains any OR relations.
101
	 *
102
	 * @since 4.3.0
103
	 * @access protected
104
	 * @var bool
105
	 */
106
	protected $has_or_relation = false;
107
108
	/**
109
	 * Constructor.
110
	 *
111
	 * @since 3.2.0
112
	 * @since 4.2.0 Introduced support for naming query clauses by associative array keys.
113
	 *
114
	 * @access public
115
	 *
116
	 * @param array $meta_query {
0 ignored issues
show
Documentation introduced by
Should the type for parameter $meta_query not be false|array? Also, consider making the array more specific, something like array<String>, or String[].

This check looks for @param annotations where the type inferred by our type inference engine differs from the declared type.

It makes a suggestion as to what type it considers more descriptive. In addition it looks for parameters that have the generic type array and suggests a stricter type like array<String>.

Most often this is a case of a parameter that can be null in addition to its declared types.

Loading history...
117
	 *     Array of meta query clauses. When first-order clauses or sub-clauses use strings as
118
	 *     their array keys, they may be referenced in the 'orderby' parameter of the parent query.
119
	 *
120
	 *     @type string $relation Optional. The MySQL keyword used to join
121
	 *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
122
	 *     @type array {
123
	 *         Optional. An array of first-order clause parameters, or another fully-formed meta query.
124
	 *
125
	 *         @type string $key     Meta key to filter by.
126
	 *         @type string $value   Meta value to filter by.
127
	 *         @type string $compare MySQL operator used for comparing the $value. Accepts '=',
128
	 *                               '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE',
129
	 *                               'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN', 'REGEXP',
130
	 *                               'NOT REGEXP', 'RLIKE', 'EXISTS' or 'NOT EXISTS'.
131
	 *                               Default is 'IN' when `$value` is an array, '=' otherwise.
132
	 *         @type string $type    MySQL data type that the meta_value column will be CAST to for
133
	 *                               comparisons. Accepts 'NUMERIC', 'BINARY', 'CHAR', 'DATE',
134
	 *                               'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', or 'UNSIGNED'.
135
	 *                               Default is 'CHAR'.
136
	 *     }
137
	 * }
138
	 */
139
	public function __construct( $meta_query = false ) {
140
		if ( !$meta_query )
141
			return;
142
143 View Code Duplication
		if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {
144
			$this->relation = 'OR';
145
		} else {
146
			$this->relation = 'AND';
147
		}
148
149
		$this->queries = $this->sanitize_query( $meta_query );
150
	}
151
152
	/**
153
	 * Ensure the 'meta_query' argument passed to the class constructor is well-formed.
154
	 *
155
	 * Eliminates empty items and ensures that a 'relation' is set.
156
	 *
157
	 * @since 4.1.0
158
	 * @access public
159
	 *
160
	 * @param array $queries Array of query clauses.
161
	 * @return array Sanitized array of query clauses.
162
	 */
163
	public function sanitize_query( $queries ) {
164
		$clean_queries = array();
165
166
		if ( ! is_array( $queries ) ) {
167
			return $clean_queries;
168
		}
169
170
		foreach ( $queries as $key => $query ) {
171
			if ( 'relation' === $key ) {
172
				$relation = $query;
173
174
			} elseif ( ! is_array( $query ) ) {
175
				continue;
176
177
			// First-order clause.
178
			} elseif ( $this->is_first_order_clause( $query ) ) {
179
				if ( isset( $query['value'] ) && array() === $query['value'] ) {
180
					unset( $query['value'] );
181
				}
182
183
				$clean_queries[ $key ] = $query;
184
185
			// Otherwise, it's a nested query, so we recurse.
186
			} else {
187
				$cleaned_query = $this->sanitize_query( $query );
188
189
				if ( ! empty( $cleaned_query ) ) {
190
					$clean_queries[ $key ] = $cleaned_query;
191
				}
192
			}
193
		}
194
195
		if ( empty( $clean_queries ) ) {
196
			return $clean_queries;
197
		}
198
199
		// Sanitize the 'relation' key provided in the query.
200
		if ( isset( $relation ) && 'OR' === strtoupper( $relation ) ) {
201
			$clean_queries['relation'] = 'OR';
202
			$this->has_or_relation = true;
203
204
		/*
205
		 * If there is only a single clause, call the relation 'OR'.
206
		 * This value will not actually be used to join clauses, but it
207
		 * simplifies the logic around combining key-only queries.
208
		 */
209
		} elseif ( 1 === count( $clean_queries ) ) {
210
			$clean_queries['relation'] = 'OR';
211
212
		// Default to AND.
213
		} else {
214
			$clean_queries['relation'] = 'AND';
215
		}
216
217
		return $clean_queries;
218
	}
219
220
	/**
221
	 * Determine whether a query clause is first-order.
222
	 *
223
	 * A first-order meta query clause is one that has either a 'key' or
224
	 * a 'value' array key.
225
	 *
226
	 * @since 4.1.0
227
	 * @access protected
228
	 *
229
	 * @param array $query Meta query arguments.
230
	 * @return bool Whether the query clause is a first-order clause.
231
	 */
232
	protected function is_first_order_clause( $query ) {
233
		return isset( $query['key'] ) || isset( $query['value'] );
234
	}
235
236
	/**
237
	 * Constructs a meta query based on 'meta_*' query vars
238
	 *
239
	 * @since 3.2.0
240
	 * @access public
241
	 *
242
	 * @param array $qv The query variables
243
	 */
244
	public function parse_query_vars( $qv ) {
245
		$meta_query = array();
246
247
		/*
248
		 * For orderby=meta_value to work correctly, simple query needs to be
249
		 * first (so that its table join is against an unaliased meta table) and
250
		 * needs to be its own clause (so it doesn't interfere with the logic of
251
		 * the rest of the meta_query).
252
		 */
253
		$primary_meta_query = array();
254
		foreach ( array( 'key', 'compare', 'type' ) as $key ) {
255
			if ( ! empty( $qv[ "meta_$key" ] ) ) {
256
				$primary_meta_query[ $key ] = $qv[ "meta_$key" ];
257
			}
258
		}
259
260
		// WP_Query sets 'meta_value' = '' by default.
261
		if ( isset( $qv['meta_value'] ) && '' !== $qv['meta_value'] && ( ! is_array( $qv['meta_value'] ) || $qv['meta_value'] ) ) {
262
			$primary_meta_query['value'] = $qv['meta_value'];
263
		}
264
265
		$existing_meta_query = isset( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ? $qv['meta_query'] : array();
266
267
		if ( ! empty( $primary_meta_query ) && ! empty( $existing_meta_query ) ) {
268
			$meta_query = array(
269
				'relation' => 'AND',
270
				$primary_meta_query,
271
				$existing_meta_query,
272
			);
273
		} elseif ( ! empty( $primary_meta_query ) ) {
274
			$meta_query = array(
275
				$primary_meta_query,
276
			);
277
		} elseif ( ! empty( $existing_meta_query ) ) {
278
			$meta_query = $existing_meta_query;
279
		}
280
281
		$this->__construct( $meta_query );
282
	}
283
284
	/**
285
	 * Return the appropriate alias for the given meta type if applicable.
286
	 *
287
	 * @since 3.7.0
288
	 * @access public
289
	 *
290
	 * @param string $type MySQL type to cast meta_value.
291
	 * @return string MySQL type.
292
	 */
293
	public function get_cast_for_type( $type = '' ) {
294
		if ( empty( $type ) )
295
			return 'CHAR';
296
297
		$meta_type = strtoupper( $type );
298
299
		if ( ! preg_match( '/^(?:BINARY|CHAR|DATE|DATETIME|SIGNED|UNSIGNED|TIME|NUMERIC(?:\(\d+(?:,\s?\d+)?\))?|DECIMAL(?:\(\d+(?:,\s?\d+)?\))?)$/', $meta_type ) )
300
			return 'CHAR';
301
302
		if ( 'NUMERIC' == $meta_type )
303
			$meta_type = 'SIGNED';
304
305
		return $meta_type;
306
	}
307
308
	/**
309
	 * Generates SQL clauses to be appended to a main query.
310
	 *
311
	 * @since 3.2.0
312
	 * @access public
313
	 *
314
	 * @param string $type              Type of meta, eg 'user', 'post'.
315
	 * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).
316
	 * @param string $primary_id_column ID column for the filtered object in $primary_table.
317
	 * @param object $context           Optional. The main query object.
318
	 * @return false|array {
319
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
320
	 *
321
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
322
	 *     @type string $where SQL fragment to append to the main WHERE clause.
323
	 * }
324
	 */
325
	public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
326
		if ( ! $meta_table = _get_meta_table( $type ) ) {
327
			return false;
328
		}
329
330
		$this->table_aliases = array();
331
332
		$this->meta_table     = $meta_table;
333
		$this->meta_id_column = sanitize_key( $type . '_id' );
334
335
		$this->primary_table     = $primary_table;
336
		$this->primary_id_column = $primary_id_column;
337
338
		$sql = $this->get_sql_clauses();
339
340
		/*
341
		 * If any JOINs are LEFT JOINs (as in the case of NOT EXISTS), then all JOINs should
342
		 * be LEFT. Otherwise posts with no metadata will be excluded from results.
343
		 */
344
		if ( false !== strpos( $sql['join'], 'LEFT JOIN' ) ) {
345
			$sql['join'] = str_replace( 'INNER JOIN', 'LEFT JOIN', $sql['join'] );
346
		}
347
348
		/**
349
		 * Filters the meta query's generated SQL.
350
		 *
351
		 * @since 3.1.0
352
		 *
353
		 * @param array  $clauses           Array containing the query's JOIN and WHERE clauses.
354
		 * @param array  $queries           Array of meta queries.
355
		 * @param string $type              Type of meta.
356
		 * @param string $primary_table     Primary table.
357
		 * @param string $primary_id_column Primary column ID.
358
		 * @param object $context           The main query object.
359
		 */
360
		return apply_filters_ref_array( 'get_meta_sql', array( $sql, $this->queries, $type, $primary_table, $primary_id_column, $context ) );
361
	}
362
363
	/**
364
	 * Generate SQL clauses to be appended to a main query.
365
	 *
366
	 * Called by the public WP_Meta_Query::get_sql(), this method is abstracted
367
	 * out to maintain parity with the other Query classes.
368
	 *
369
	 * @since 4.1.0
370
	 * @access protected
371
	 *
372
	 * @return array {
0 ignored issues
show
Documentation introduced by
Consider making the return type a bit more specific; maybe use array<string,string>.

This check looks for the generic type array as a return type and suggests a more specific type. This type is inferred from the actual code.

Loading history...
373
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
374
	 *
375
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
376
	 *     @type string $where SQL fragment to append to the main WHERE clause.
377
	 * }
378
	 */
379 View Code Duplication
	protected function get_sql_clauses() {
380
		/*
381
		 * $queries are passed by reference to get_sql_for_query() for recursion.
382
		 * To keep $this->queries unaltered, pass a copy.
383
		 */
384
		$queries = $this->queries;
385
		$sql = $this->get_sql_for_query( $queries );
386
387
		if ( ! empty( $sql['where'] ) ) {
388
			$sql['where'] = ' AND ' . $sql['where'];
389
		}
390
391
		return $sql;
392
	}
393
394
	/**
395
	 * Generate SQL clauses for a single query array.
396
	 *
397
	 * If nested subqueries are found, this method recurses the tree to
398
	 * produce the properly nested SQL.
399
	 *
400
	 * @since 4.1.0
401
	 * @access protected
402
	 *
403
	 * @param array $query Query to parse, passed by reference.
404
	 * @param int   $depth Optional. Number of tree levels deep we currently are.
405
	 *                     Used to calculate indentation. Default 0.
406
	 * @return array {
0 ignored issues
show
Documentation introduced by
Consider making the return type a bit more specific; maybe use array<string,string>.

This check looks for the generic type array as a return type and suggests a more specific type. This type is inferred from the actual code.

Loading history...
407
	 *     Array containing JOIN and WHERE SQL clauses to append to a single query array.
408
	 *
409
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
410
	 *     @type string $where SQL fragment to append to the main WHERE clause.
411
	 * }
412
	 */
413 View Code Duplication
	protected function get_sql_for_query( &$query, $depth = 0 ) {
414
		$sql_chunks = array(
415
			'join'  => array(),
416
			'where' => array(),
417
		);
418
419
		$sql = array(
420
			'join'  => '',
421
			'where' => '',
422
		);
423
424
		$indent = '';
425
		for ( $i = 0; $i < $depth; $i++ ) {
426
			$indent .= "  ";
427
		}
428
429
		foreach ( $query as $key => &$clause ) {
430
			if ( 'relation' === $key ) {
431
				$relation = $query['relation'];
432
			} elseif ( is_array( $clause ) ) {
433
434
				// This is a first-order clause.
435
				if ( $this->is_first_order_clause( $clause ) ) {
436
					$clause_sql = $this->get_sql_for_clause( $clause, $query, $key );
437
438
					$where_count = count( $clause_sql['where'] );
439
					if ( ! $where_count ) {
440
						$sql_chunks['where'][] = '';
441
					} elseif ( 1 === $where_count ) {
442
						$sql_chunks['where'][] = $clause_sql['where'][0];
443
					} else {
444
						$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
445
					}
446
447
					$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
448
				// This is a subquery, so we recurse.
449
				} else {
450
					$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );
451
452
					$sql_chunks['where'][] = $clause_sql['where'];
453
					$sql_chunks['join'][]  = $clause_sql['join'];
454
				}
455
			}
456
		}
457
458
		// Filter to remove empties.
459
		$sql_chunks['join']  = array_filter( $sql_chunks['join'] );
460
		$sql_chunks['where'] = array_filter( $sql_chunks['where'] );
461
462
		if ( empty( $relation ) ) {
463
			$relation = 'AND';
464
		}
465
466
		// Filter duplicate JOIN clauses and combine into a single string.
467
		if ( ! empty( $sql_chunks['join'] ) ) {
468
			$sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
469
		}
470
471
		// Generate a single WHERE clause with proper brackets and indentation.
472
		if ( ! empty( $sql_chunks['where'] ) ) {
473
			$sql['where'] = '( ' . "\n  " . $indent . implode( ' ' . "\n  " . $indent . $relation . ' ' . "\n  " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
474
		}
475
476
		return $sql;
477
	}
478
479
	/**
480
	 * Generate SQL JOIN and WHERE clauses for a first-order query clause.
481
	 *
482
	 * "First-order" means that it's an array with a 'key' or 'value'.
483
	 *
484
	 * @since 4.1.0
485
	 * @access public
486
	 *
487
	 * @global wpdb $wpdb WordPress database abstraction object.
488
	 *
489
	 * @param array  $clause       Query clause, passed by reference.
490
	 * @param array  $parent_query Parent query array.
491
	 * @param string $clause_key   Optional. The array key used to name the clause in the original `$meta_query`
492
	 *                             parameters. If not provided, a key will be generated automatically.
493
	 * @return array {
0 ignored issues
show
Documentation introduced by
Consider making the return type a bit more specific; maybe use array<string,array>.

This check looks for the generic type array as a return type and suggests a more specific type. This type is inferred from the actual code.

Loading history...
494
	 *     Array containing JOIN and WHERE SQL clauses to append to a first-order query.
495
	 *
496
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
497
	 *     @type string $where SQL fragment to append to the main WHERE clause.
498
	 * }
499
	 */
500
	public function get_sql_for_clause( &$clause, $parent_query, $clause_key = '' ) {
501
		global $wpdb;
502
503
		$sql_chunks = array(
504
			'where' => array(),
505
			'join' => array(),
506
		);
507
508
		if ( isset( $clause['compare'] ) ) {
509
			$clause['compare'] = strtoupper( $clause['compare'] );
510
		} else {
511
			$clause['compare'] = isset( $clause['value'] ) && is_array( $clause['value'] ) ? 'IN' : '=';
512
		}
513
514
		if ( ! in_array( $clause['compare'], array(
515
			'=', '!=', '>', '>=', '<', '<=',
516
			'LIKE', 'NOT LIKE',
517
			'IN', 'NOT IN',
518
			'BETWEEN', 'NOT BETWEEN',
519
			'EXISTS', 'NOT EXISTS',
520
			'REGEXP', 'NOT REGEXP', 'RLIKE'
521
		) ) ) {
522
			$clause['compare'] = '=';
523
		}
524
525
		$meta_compare = $clause['compare'];
526
527
		// First build the JOIN clause, if one is required.
528
		$join = '';
529
530
		// We prefer to avoid joins if possible. Look for an existing join compatible with this clause.
531
		$alias = $this->find_compatible_table_alias( $clause, $parent_query );
532
		if ( false === $alias ) {
533
			$i = count( $this->table_aliases );
534
			$alias = $i ? 'mt' . $i : $this->meta_table;
535
536
			// JOIN clauses for NOT EXISTS have their own syntax.
537
			if ( 'NOT EXISTS' === $meta_compare ) {
538
				$join .= " LEFT JOIN $this->meta_table";
539
				$join .= $i ? " AS $alias" : '';
540
				$join .= $wpdb->prepare( " ON ($this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key = %s )", $clause['key'] );
541
542
			// All other JOIN clauses.
543
			} else {
544
				$join .= " INNER JOIN $this->meta_table";
545
				$join .= $i ? " AS $alias" : '';
546
				$join .= " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column )";
547
			}
548
549
			$this->table_aliases[] = $alias;
550
			$sql_chunks['join'][] = $join;
551
		}
552
553
		// Save the alias to this clause, for future siblings to find.
554
		$clause['alias'] = $alias;
555
556
		// Determine the data type.
557
		$_meta_type = isset( $clause['type'] ) ? $clause['type'] : '';
558
		$meta_type  = $this->get_cast_for_type( $_meta_type );
559
		$clause['cast'] = $meta_type;
560
561
		// Fallback for clause keys is the table alias. Key must be a string.
562
		if ( is_int( $clause_key ) || ! $clause_key ) {
563
			$clause_key = $clause['alias'];
564
		}
565
566
		// Ensure unique clause keys, so none are overwritten.
567
		$iterator = 1;
568
		$clause_key_base = $clause_key;
569
		while ( isset( $this->clauses[ $clause_key ] ) ) {
570
			$clause_key = $clause_key_base . '-' . $iterator;
571
			$iterator++;
572
		}
573
574
		// Store the clause in our flat array.
575
		$this->clauses[ $clause_key ] =& $clause;
576
577
		// Next, build the WHERE clause.
578
579
		// meta_key.
580
		if ( array_key_exists( 'key', $clause ) ) {
581
			if ( 'NOT EXISTS' === $meta_compare ) {
582
				$sql_chunks['where'][] = $alias . '.' . $this->meta_id_column . ' IS NULL';
583
			} else {
584
				$sql_chunks['where'][] = $wpdb->prepare( "$alias.meta_key = %s", trim( $clause['key'] ) );
585
			}
586
		}
587
588
		// meta_value.
589
		if ( array_key_exists( 'value', $clause ) ) {
590
			$meta_value = $clause['value'];
591
592
			if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {
593
				if ( ! is_array( $meta_value ) ) {
594
					$meta_value = preg_split( '/[,\s]+/', $meta_value );
595
				}
596
			} else {
597
				$meta_value = trim( $meta_value );
598
			}
599
600
			switch ( $meta_compare ) {
601
				case 'IN' :
602
				case 'NOT IN' :
603
					$meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
604
					$where = $wpdb->prepare( $meta_compare_string, $meta_value );
605
					break;
606
607
				case 'BETWEEN' :
608
				case 'NOT BETWEEN' :
609
					$meta_value = array_slice( $meta_value, 0, 2 );
610
					$where = $wpdb->prepare( '%s AND %s', $meta_value );
611
					break;
612
613
				case 'LIKE' :
614
				case 'NOT LIKE' :
615
					$meta_value = '%' . $wpdb->esc_like( $meta_value ) . '%';
616
					$where = $wpdb->prepare( '%s', $meta_value );
617
					break;
618
619
				// EXISTS with a value is interpreted as '='.
620
				case 'EXISTS' :
621
					$meta_compare = '=';
622
					$where = $wpdb->prepare( '%s', $meta_value );
623
					break;
624
625
				// 'value' is ignored for NOT EXISTS.
626
				case 'NOT EXISTS' :
627
					$where = '';
628
					break;
629
630
				default :
631
					$where = $wpdb->prepare( '%s', $meta_value );
632
					break;
633
634
			}
635
636
			if ( $where ) {
637
				if ( 'CHAR' === $meta_type ) {
638
					$sql_chunks['where'][] = "$alias.meta_value {$meta_compare} {$where}";
639
				} else {
640
					$sql_chunks['where'][] = "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$where}";
641
				}
642
			}
643
		}
644
645
		/*
646
		 * Multiple WHERE clauses (for meta_key and meta_value) should
647
		 * be joined in parentheses.
648
		 */
649
		if ( 1 < count( $sql_chunks['where'] ) ) {
650
			$sql_chunks['where'] = array( '( ' . implode( ' AND ', $sql_chunks['where'] ) . ' )' );
651
		}
652
653
		return $sql_chunks;
654
	}
655
656
	/**
657
	 * Get a flattened list of sanitized meta clauses.
658
	 *
659
	 * This array should be used for clause lookup, as when the table alias and CAST type must be determined for
660
	 * a value of 'orderby' corresponding to a meta clause.
661
	 *
662
	 * @since 4.2.0
663
	 * @access public
664
	 *
665
	 * @return array Meta clauses.
666
	 */
667
	public function get_clauses() {
668
		return $this->clauses;
669
	}
670
671
	/**
672
	 * Identify an existing table alias that is compatible with the current
673
	 * query clause.
674
	 *
675
	 * We avoid unnecessary table joins by allowing each clause to look for
676
	 * an existing table alias that is compatible with the query that it
677
	 * needs to perform.
678
	 *
679
	 * An existing alias is compatible if (a) it is a sibling of `$clause`
680
	 * (ie, it's under the scope of the same relation), and (b) the combination
681
	 * of operator and relation between the clauses allows for a shared table join.
682
	 * In the case of WP_Meta_Query, this only applies to 'IN' clauses that are
683
	 * connected by the relation 'OR'.
684
	 *
685
	 * @since 4.1.0
686
	 * @access protected
687
	 *
688
	 * @param  array       $clause       Query clause.
689
	 * @param  array       $parent_query Parent query of $clause.
690
	 * @return string|bool Table alias if found, otherwise false.
691
	 */
692
	protected function find_compatible_table_alias( $clause, $parent_query ) {
693
		$alias = false;
694
695
		foreach ( $parent_query as $sibling ) {
696
			// If the sibling has no alias yet, there's nothing to check.
697
			if ( empty( $sibling['alias'] ) ) {
698
				continue;
699
			}
700
701
			// We're only interested in siblings that are first-order clauses.
702
			if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
703
				continue;
704
			}
705
706
			$compatible_compares = array();
707
708
			// Clauses connected by OR can share joins as long as they have "positive" operators.
709
			if ( 'OR' === $parent_query['relation'] ) {
710
				$compatible_compares = array( '=', 'IN', 'BETWEEN', 'LIKE', 'REGEXP', 'RLIKE', '>', '>=', '<', '<=' );
711
712
			// Clauses joined by AND with "negative" operators share a join only if they also share a key.
713
			} elseif ( isset( $sibling['key'] ) && isset( $clause['key'] ) && $sibling['key'] === $clause['key'] ) {
714
				$compatible_compares = array( '!=', 'NOT IN', 'NOT LIKE' );
715
			}
716
717
			$clause_compare  = strtoupper( $clause['compare'] );
718
			$sibling_compare = strtoupper( $sibling['compare'] );
719
			if ( in_array( $clause_compare, $compatible_compares ) && in_array( $sibling_compare, $compatible_compares ) ) {
720
				$alias = $sibling['alias'];
721
				break;
722
			}
723
		}
724
725
		/**
726
		 * Filters the table alias identified as compatible with the current clause.
727
		 *
728
		 * @since 4.1.0
729
		 *
730
		 * @param string|bool $alias        Table alias, or false if none was found.
731
		 * @param array       $clause       First-order query clause.
732
		 * @param array       $parent_query Parent of $clause.
733
		 * @param object      $this         WP_Meta_Query object.
734
		 */
735
		return apply_filters( 'meta_query_find_compatible_table_alias', $alias, $clause, $parent_query, $this ) ;
736
	}
737
738
	/**
739
	 * Checks whether the current query has any OR relations.
740
	 *
741
	 * In some cases, the presence of an OR relation somewhere in the query will require
742
	 * the use of a `DISTINCT` or `GROUP BY` keyword in the `SELECT` clause. The current
743
	 * method can be used in these cases to determine whether such a clause is necessary.
744
	 *
745
	 * @since 4.3.0
746
	 *
747
	 * @return bool True if the query contains any `OR` relations, otherwise false.
748
	 */
749
	public function has_or_relation() {
750
		return $this->has_or_relation;
751
	}
752
}
753