--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-meta-query.php Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,730 @@
+<?php
+/**
+ * Meta API: WP_Meta_Query class
+ *
+ * @package WordPress
+ * @subpackage Meta
+ * @since 4.4.0
+ */
+
+/**
+ * Core class used to implement meta queries for the Meta API.
+ *
+ * Used for generating SQL clauses that filter a primary query according to metadata keys and values.
+ *
+ * WP_Meta_Query is a helper that allows primary query classes, such as WP_Query and WP_User_Query,
+ *
+ * to filter their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be attached
+ * to the primary SQL query string.
+ *
+ * @since 3.2.0
+ */
+class WP_Meta_Query {
+ /**
+ * Array of metadata queries.
+ *
+ * See WP_Meta_Query::__construct() for information on meta query arguments.
+ *
+ * @since 3.2.0
+ * @var array
+ */
+ public $queries = array();
+
+ /**
+ * The relation between the queries. Can be one of 'AND' or 'OR'.
+ *
+ * @since 3.2.0
+ * @var string
+ */
+ public $relation;
+
+ /**
+ * Database table to query for the metadata.
+ *
+ * @since 4.1.0
+ * @var string
+ */
+ public $meta_table;
+
+ /**
+ * Column in meta_table that represents the ID of the object the metadata belongs to.
+ *
+ * @since 4.1.0
+ * @var string
+ */
+ public $meta_id_column;
+
+ /**
+ * Database table that where the metadata's objects are stored (eg $wpdb->users).
+ *
+ * @since 4.1.0
+ * @var string
+ */
+ public $primary_table;
+
+ /**
+ * Column in primary_table that represents the ID of the object.
+ *
+ * @since 4.1.0
+ * @var string
+ */
+ public $primary_id_column;
+
+ /**
+ * A flat list of table aliases used in JOIN clauses.
+ *
+ * @since 4.1.0
+ * @var array
+ */
+ protected $table_aliases = array();
+
+ /**
+ * A flat list of clauses, keyed by clause 'name'.
+ *
+ * @since 4.2.0
+ * @var array
+ */
+ protected $clauses = array();
+
+ /**
+ * Whether the query contains any OR relations.
+ *
+ * @since 4.3.0
+ * @var bool
+ */
+ protected $has_or_relation = false;
+
+ /**
+ * Constructor.
+ *
+ * @since 3.2.0
+ * @since 4.2.0 Introduced support for naming query clauses by associative array keys.
+ *
+ *
+ * @param array $meta_query {
+ * Array of meta query clauses. When first-order clauses or sub-clauses use strings as
+ * their array keys, they may be referenced in the 'orderby' parameter of the parent query.
+ *
+ * @type string $relation Optional. The MySQL keyword used to join
+ * the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
+ * @type array {
+ * Optional. An array of first-order clause parameters, or another fully-formed meta query.
+ *
+ * @type string $key Meta key to filter by.
+ * @type string $value Meta value to filter by.
+ * @type string $compare MySQL operator used for comparing the $value. Accepts '=',
+ * '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE',
+ * 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN', 'REGEXP',
+ * 'NOT REGEXP', 'RLIKE', 'EXISTS' or 'NOT EXISTS'.
+ * Default is 'IN' when `$value` is an array, '=' otherwise.
+ * @type string $type MySQL data type that the meta_value column will be CAST to for
+ * comparisons. Accepts 'NUMERIC', 'BINARY', 'CHAR', 'DATE',
+ * 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', or 'UNSIGNED'.
+ * Default is 'CHAR'.
+ * }
+ * }
+ */
+ public function __construct( $meta_query = false ) {
+ if ( !$meta_query )
+ return;
+
+ if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {
+ $this->relation = 'OR';
+ } else {
+ $this->relation = 'AND';
+ }
+
+ $this->queries = $this->sanitize_query( $meta_query );
+ }
+
+ /**
+ * Ensure the 'meta_query' argument passed to the class constructor is well-formed.
+ *
+ * Eliminates empty items and ensures that a 'relation' is set.
+ *
+ * @since 4.1.0
+ *
+ * @param array $queries Array of query clauses.
+ * @return array Sanitized array of query clauses.
+ */
+ public function sanitize_query( $queries ) {
+ $clean_queries = array();
+
+ if ( ! is_array( $queries ) ) {
+ return $clean_queries;
+ }
+
+ foreach ( $queries as $key => $query ) {
+ if ( 'relation' === $key ) {
+ $relation = $query;
+
+ } elseif ( ! is_array( $query ) ) {
+ continue;
+
+ // First-order clause.
+ } elseif ( $this->is_first_order_clause( $query ) ) {
+ if ( isset( $query['value'] ) && array() === $query['value'] ) {
+ unset( $query['value'] );
+ }
+
+ $clean_queries[ $key ] = $query;
+
+ // Otherwise, it's a nested query, so we recurse.
+ } else {
+ $cleaned_query = $this->sanitize_query( $query );
+
+ if ( ! empty( $cleaned_query ) ) {
+ $clean_queries[ $key ] = $cleaned_query;
+ }
+ }
+ }
+
+ if ( empty( $clean_queries ) ) {
+ return $clean_queries;
+ }
+
+ // Sanitize the 'relation' key provided in the query.
+ if ( isset( $relation ) && 'OR' === strtoupper( $relation ) ) {
+ $clean_queries['relation'] = 'OR';
+ $this->has_or_relation = true;
+
+ /*
+ * If there is only a single clause, call the relation 'OR'.
+ * This value will not actually be used to join clauses, but it
+ * simplifies the logic around combining key-only queries.
+ */
+ } elseif ( 1 === count( $clean_queries ) ) {
+ $clean_queries['relation'] = 'OR';
+
+ // Default to AND.
+ } else {
+ $clean_queries['relation'] = 'AND';
+ }
+
+ return $clean_queries;
+ }
+
+ /**
+ * Determine whether a query clause is first-order.
+ *
+ * A first-order meta query clause is one that has either a 'key' or
+ * a 'value' array key.
+ *
+ * @since 4.1.0
+ *
+ * @param array $query Meta query arguments.
+ * @return bool Whether the query clause is a first-order clause.
+ */
+ protected function is_first_order_clause( $query ) {
+ return isset( $query['key'] ) || isset( $query['value'] );
+ }
+
+ /**
+ * Constructs a meta query based on 'meta_*' query vars
+ *
+ * @since 3.2.0
+ *
+ * @param array $qv The query variables
+ */
+ public function parse_query_vars( $qv ) {
+ $meta_query = array();
+
+ /*
+ * For orderby=meta_value to work correctly, simple query needs to be
+ * first (so that its table join is against an unaliased meta table) and
+ * needs to be its own clause (so it doesn't interfere with the logic of
+ * the rest of the meta_query).
+ */
+ $primary_meta_query = array();
+ foreach ( array( 'key', 'compare', 'type' ) as $key ) {
+ if ( ! empty( $qv[ "meta_$key" ] ) ) {
+ $primary_meta_query[ $key ] = $qv[ "meta_$key" ];
+ }
+ }
+
+ // WP_Query sets 'meta_value' = '' by default.
+ if ( isset( $qv['meta_value'] ) && '' !== $qv['meta_value'] && ( ! is_array( $qv['meta_value'] ) || $qv['meta_value'] ) ) {
+ $primary_meta_query['value'] = $qv['meta_value'];
+ }
+
+ $existing_meta_query = isset( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ? $qv['meta_query'] : array();
+
+ if ( ! empty( $primary_meta_query ) && ! empty( $existing_meta_query ) ) {
+ $meta_query = array(
+ 'relation' => 'AND',
+ $primary_meta_query,
+ $existing_meta_query,
+ );
+ } elseif ( ! empty( $primary_meta_query ) ) {
+ $meta_query = array(
+ $primary_meta_query,
+ );
+ } elseif ( ! empty( $existing_meta_query ) ) {
+ $meta_query = $existing_meta_query;
+ }
+
+ $this->__construct( $meta_query );
+ }
+
+ /**
+ * Return the appropriate alias for the given meta type if applicable.
+ *
+ * @since 3.7.0
+ *
+ * @param string $type MySQL type to cast meta_value.
+ * @return string MySQL type.
+ */
+ public function get_cast_for_type( $type = '' ) {
+ if ( empty( $type ) )
+ return 'CHAR';
+
+ $meta_type = strtoupper( $type );
+
+ if ( ! preg_match( '/^(?:BINARY|CHAR|DATE|DATETIME|SIGNED|UNSIGNED|TIME|NUMERIC(?:\(\d+(?:,\s?\d+)?\))?|DECIMAL(?:\(\d+(?:,\s?\d+)?\))?)$/', $meta_type ) )
+ return 'CHAR';
+
+ if ( 'NUMERIC' == $meta_type )
+ $meta_type = 'SIGNED';
+
+ return $meta_type;
+ }
+
+ /**
+ * Generates SQL clauses to be appended to a main query.
+ *
+ * @since 3.2.0
+ *
+ * @param string $type Type of meta, eg 'user', 'post'.
+ * @param string $primary_table Database table where the object being filtered is stored (eg wp_users).
+ * @param string $primary_id_column ID column for the filtered object in $primary_table.
+ * @param object $context Optional. The main query object.
+ * @return false|array {
+ * Array containing JOIN and WHERE SQL clauses to append to the main query.
+ *
+ * @type string $join SQL fragment to append to the main JOIN clause.
+ * @type string $where SQL fragment to append to the main WHERE clause.
+ * }
+ */
+ public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
+ if ( ! $meta_table = _get_meta_table( $type ) ) {
+ return false;
+ }
+
+ $this->table_aliases = array();
+
+ $this->meta_table = $meta_table;
+ $this->meta_id_column = sanitize_key( $type . '_id' );
+
+ $this->primary_table = $primary_table;
+ $this->primary_id_column = $primary_id_column;
+
+ $sql = $this->get_sql_clauses();
+
+ /*
+ * If any JOINs are LEFT JOINs (as in the case of NOT EXISTS), then all JOINs should
+ * be LEFT. Otherwise posts with no metadata will be excluded from results.
+ */
+ if ( false !== strpos( $sql['join'], 'LEFT JOIN' ) ) {
+ $sql['join'] = str_replace( 'INNER JOIN', 'LEFT JOIN', $sql['join'] );
+ }
+
+ /**
+ * Filters the meta query's generated SQL.
+ *
+ * @since 3.1.0
+ *
+ * @param array $clauses Array containing the query's JOIN and WHERE clauses.
+ * @param array $queries Array of meta queries.
+ * @param string $type Type of meta.
+ * @param string $primary_table Primary table.
+ * @param string $primary_id_column Primary column ID.
+ * @param object $context The main query object.
+ */
+ return apply_filters_ref_array( 'get_meta_sql', array( $sql, $this->queries, $type, $primary_table, $primary_id_column, $context ) );
+ }
+
+ /**
+ * Generate SQL clauses to be appended to a main query.
+ *
+ * Called by the public WP_Meta_Query::get_sql(), this method is abstracted
+ * out to maintain parity with the other Query classes.
+ *
+ * @since 4.1.0
+ *
+ * @return array {
+ * Array containing JOIN and WHERE SQL clauses to append to the main query.
+ *
+ * @type string $join SQL fragment to append to the main JOIN clause.
+ * @type string $where SQL fragment to append to the main WHERE clause.
+ * }
+ */
+ protected function get_sql_clauses() {
+ /*
+ * $queries are passed by reference to get_sql_for_query() for recursion.
+ * To keep $this->queries unaltered, pass a copy.
+ */
+ $queries = $this->queries;
+ $sql = $this->get_sql_for_query( $queries );
+
+ if ( ! empty( $sql['where'] ) ) {
+ $sql['where'] = ' AND ' . $sql['where'];
+ }
+
+ return $sql;
+ }
+
+ /**
+ * Generate SQL clauses for a single query array.
+ *
+ * If nested subqueries are found, this method recurses the tree to
+ * produce the properly nested SQL.
+ *
+ * @since 4.1.0
+ *
+ * @param array $query Query to parse (passed by reference).
+ * @param int $depth Optional. Number of tree levels deep we currently are.
+ * Used to calculate indentation. Default 0.
+ * @return array {
+ * Array containing JOIN and WHERE SQL clauses to append to a single query array.
+ *
+ * @type string $join SQL fragment to append to the main JOIN clause.
+ * @type string $where SQL fragment to append to the main WHERE clause.
+ * }
+ */
+ protected function get_sql_for_query( &$query, $depth = 0 ) {
+ $sql_chunks = array(
+ 'join' => array(),
+ 'where' => array(),
+ );
+
+ $sql = array(
+ 'join' => '',
+ 'where' => '',
+ );
+
+ $indent = '';
+ for ( $i = 0; $i < $depth; $i++ ) {
+ $indent .= " ";
+ }
+
+ foreach ( $query as $key => &$clause ) {
+ if ( 'relation' === $key ) {
+ $relation = $query['relation'];
+ } elseif ( is_array( $clause ) ) {
+
+ // This is a first-order clause.
+ if ( $this->is_first_order_clause( $clause ) ) {
+ $clause_sql = $this->get_sql_for_clause( $clause, $query, $key );
+
+ $where_count = count( $clause_sql['where'] );
+ if ( ! $where_count ) {
+ $sql_chunks['where'][] = '';
+ } elseif ( 1 === $where_count ) {
+ $sql_chunks['where'][] = $clause_sql['where'][0];
+ } else {
+ $sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
+ }
+
+ $sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
+ // This is a subquery, so we recurse.
+ } else {
+ $clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );
+
+ $sql_chunks['where'][] = $clause_sql['where'];
+ $sql_chunks['join'][] = $clause_sql['join'];
+ }
+ }
+ }
+
+ // Filter to remove empties.
+ $sql_chunks['join'] = array_filter( $sql_chunks['join'] );
+ $sql_chunks['where'] = array_filter( $sql_chunks['where'] );
+
+ if ( empty( $relation ) ) {
+ $relation = 'AND';
+ }
+
+ // Filter duplicate JOIN clauses and combine into a single string.
+ if ( ! empty( $sql_chunks['join'] ) ) {
+ $sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
+ }
+
+ // Generate a single WHERE clause with proper brackets and indentation.
+ if ( ! empty( $sql_chunks['where'] ) ) {
+ $sql['where'] = '( ' . "\n " . $indent . implode( ' ' . "\n " . $indent . $relation . ' ' . "\n " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
+ }
+
+ return $sql;
+ }
+
+ /**
+ * Generate SQL JOIN and WHERE clauses for a first-order query clause.
+ *
+ * "First-order" means that it's an array with a 'key' or 'value'.
+ *
+ * @since 4.1.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array $clause Query clause (passed by reference).
+ * @param array $parent_query Parent query array.
+ * @param string $clause_key Optional. The array key used to name the clause in the original `$meta_query`
+ * parameters. If not provided, a key will be generated automatically.
+ * @return array {
+ * Array containing JOIN and WHERE SQL clauses to append to a first-order query.
+ *
+ * @type string $join SQL fragment to append to the main JOIN clause.
+ * @type string $where SQL fragment to append to the main WHERE clause.
+ * }
+ */
+ public function get_sql_for_clause( &$clause, $parent_query, $clause_key = '' ) {
+ global $wpdb;
+
+ $sql_chunks = array(
+ 'where' => array(),
+ 'join' => array(),
+ );
+
+ if ( isset( $clause['compare'] ) ) {
+ $clause['compare'] = strtoupper( $clause['compare'] );
+ } else {
+ $clause['compare'] = isset( $clause['value'] ) && is_array( $clause['value'] ) ? 'IN' : '=';
+ }
+
+ if ( ! in_array( $clause['compare'], array(
+ '=', '!=', '>', '>=', '<', '<=',
+ 'LIKE', 'NOT LIKE',
+ 'IN', 'NOT IN',
+ 'BETWEEN', 'NOT BETWEEN',
+ 'EXISTS', 'NOT EXISTS',
+ 'REGEXP', 'NOT REGEXP', 'RLIKE'
+ ) ) ) {
+ $clause['compare'] = '=';
+ }
+
+ $meta_compare = $clause['compare'];
+
+ // First build the JOIN clause, if one is required.
+ $join = '';
+
+ // We prefer to avoid joins if possible. Look for an existing join compatible with this clause.
+ $alias = $this->find_compatible_table_alias( $clause, $parent_query );
+ if ( false === $alias ) {
+ $i = count( $this->table_aliases );
+ $alias = $i ? 'mt' . $i : $this->meta_table;
+
+ // JOIN clauses for NOT EXISTS have their own syntax.
+ if ( 'NOT EXISTS' === $meta_compare ) {
+ $join .= " LEFT JOIN $this->meta_table";
+ $join .= $i ? " AS $alias" : '';
+ $join .= $wpdb->prepare( " ON ($this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key = %s )", $clause['key'] );
+
+ // All other JOIN clauses.
+ } else {
+ $join .= " INNER JOIN $this->meta_table";
+ $join .= $i ? " AS $alias" : '';
+ $join .= " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column )";
+ }
+
+ $this->table_aliases[] = $alias;
+ $sql_chunks['join'][] = $join;
+ }
+
+ // Save the alias to this clause, for future siblings to find.
+ $clause['alias'] = $alias;
+
+ // Determine the data type.
+ $_meta_type = isset( $clause['type'] ) ? $clause['type'] : '';
+ $meta_type = $this->get_cast_for_type( $_meta_type );
+ $clause['cast'] = $meta_type;
+
+ // Fallback for clause keys is the table alias. Key must be a string.
+ if ( is_int( $clause_key ) || ! $clause_key ) {
+ $clause_key = $clause['alias'];
+ }
+
+ // Ensure unique clause keys, so none are overwritten.
+ $iterator = 1;
+ $clause_key_base = $clause_key;
+ while ( isset( $this->clauses[ $clause_key ] ) ) {
+ $clause_key = $clause_key_base . '-' . $iterator;
+ $iterator++;
+ }
+
+ // Store the clause in our flat array.
+ $this->clauses[ $clause_key ] =& $clause;
+
+ // Next, build the WHERE clause.
+
+ // meta_key.
+ if ( array_key_exists( 'key', $clause ) ) {
+ if ( 'NOT EXISTS' === $meta_compare ) {
+ $sql_chunks['where'][] = $alias . '.' . $this->meta_id_column . ' IS NULL';
+ } else {
+ $sql_chunks['where'][] = $wpdb->prepare( "$alias.meta_key = %s", trim( $clause['key'] ) );
+ }
+ }
+
+ // meta_value.
+ if ( array_key_exists( 'value', $clause ) ) {
+ $meta_value = $clause['value'];
+
+ if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {
+ if ( ! is_array( $meta_value ) ) {
+ $meta_value = preg_split( '/[,\s]+/', $meta_value );
+ }
+ } else {
+ $meta_value = trim( $meta_value );
+ }
+
+ switch ( $meta_compare ) {
+ case 'IN' :
+ case 'NOT IN' :
+ $meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
+ $where = $wpdb->prepare( $meta_compare_string, $meta_value );
+ break;
+
+ case 'BETWEEN' :
+ case 'NOT BETWEEN' :
+ $meta_value = array_slice( $meta_value, 0, 2 );
+ $where = $wpdb->prepare( '%s AND %s', $meta_value );
+ break;
+
+ case 'LIKE' :
+ case 'NOT LIKE' :
+ $meta_value = '%' . $wpdb->esc_like( $meta_value ) . '%';
+ $where = $wpdb->prepare( '%s', $meta_value );
+ break;
+
+ // EXISTS with a value is interpreted as '='.
+ case 'EXISTS' :
+ $meta_compare = '=';
+ $where = $wpdb->prepare( '%s', $meta_value );
+ break;
+
+ // 'value' is ignored for NOT EXISTS.
+ case 'NOT EXISTS' :
+ $where = '';
+ break;
+
+ default :
+ $where = $wpdb->prepare( '%s', $meta_value );
+ break;
+
+ }
+
+ if ( $where ) {
+ if ( 'CHAR' === $meta_type ) {
+ $sql_chunks['where'][] = "$alias.meta_value {$meta_compare} {$where}";
+ } else {
+ $sql_chunks['where'][] = "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$where}";
+ }
+ }
+ }
+
+ /*
+ * Multiple WHERE clauses (for meta_key and meta_value) should
+ * be joined in parentheses.
+ */
+ if ( 1 < count( $sql_chunks['where'] ) ) {
+ $sql_chunks['where'] = array( '( ' . implode( ' AND ', $sql_chunks['where'] ) . ' )' );
+ }
+
+ return $sql_chunks;
+ }
+
+ /**
+ * Get a flattened list of sanitized meta clauses.
+ *
+ * This array should be used for clause lookup, as when the table alias and CAST type must be determined for
+ * a value of 'orderby' corresponding to a meta clause.
+ *
+ * @since 4.2.0
+ *
+ * @return array Meta clauses.
+ */
+ public function get_clauses() {
+ return $this->clauses;
+ }
+
+ /**
+ * Identify an existing table alias that is compatible with the current
+ * query clause.
+ *
+ * We avoid unnecessary table joins by allowing each clause to look for
+ * an existing table alias that is compatible with the query that it
+ * needs to perform.
+ *
+ * An existing alias is compatible if (a) it is a sibling of `$clause`
+ * (ie, it's under the scope of the same relation), and (b) the combination
+ * of operator and relation between the clauses allows for a shared table join.
+ * In the case of WP_Meta_Query, this only applies to 'IN' clauses that are
+ * connected by the relation 'OR'.
+ *
+ * @since 4.1.0
+ *
+ * @param array $clause Query clause.
+ * @param array $parent_query Parent query of $clause.
+ * @return string|bool Table alias if found, otherwise false.
+ */
+ protected function find_compatible_table_alias( $clause, $parent_query ) {
+ $alias = false;
+
+ foreach ( $parent_query as $sibling ) {
+ // If the sibling has no alias yet, there's nothing to check.
+ if ( empty( $sibling['alias'] ) ) {
+ continue;
+ }
+
+ // We're only interested in siblings that are first-order clauses.
+ if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
+ continue;
+ }
+
+ $compatible_compares = array();
+
+ // Clauses connected by OR can share joins as long as they have "positive" operators.
+ if ( 'OR' === $parent_query['relation'] ) {
+ $compatible_compares = array( '=', 'IN', 'BETWEEN', 'LIKE', 'REGEXP', 'RLIKE', '>', '>=', '<', '<=' );
+
+ // Clauses joined by AND with "negative" operators share a join only if they also share a key.
+ } elseif ( isset( $sibling['key'] ) && isset( $clause['key'] ) && $sibling['key'] === $clause['key'] ) {
+ $compatible_compares = array( '!=', 'NOT IN', 'NOT LIKE' );
+ }
+
+ $clause_compare = strtoupper( $clause['compare'] );
+ $sibling_compare = strtoupper( $sibling['compare'] );
+ if ( in_array( $clause_compare, $compatible_compares ) && in_array( $sibling_compare, $compatible_compares ) ) {
+ $alias = $sibling['alias'];
+ break;
+ }
+ }
+
+ /**
+ * Filters the table alias identified as compatible with the current clause.
+ *
+ * @since 4.1.0
+ *
+ * @param string|bool $alias Table alias, or false if none was found.
+ * @param array $clause First-order query clause.
+ * @param array $parent_query Parent of $clause.
+ * @param object $this WP_Meta_Query object.
+ */
+ return apply_filters( 'meta_query_find_compatible_table_alias', $alias, $clause, $parent_query, $this ) ;
+ }
+
+ /**
+ * Checks whether the current query has any OR relations.
+ *
+ * In some cases, the presence of an OR relation somewhere in the query will require
+ * the use of a `DISTINCT` or `GROUP BY` keyword in the `SELECT` clause. The current
+ * method can be used in these cases to determine whether such a clause is necessary.
+ *
+ * @since 4.3.0
+ *
+ * @return bool True if the query contains any `OR` relations, otherwise false.
+ */
+ public function has_or_relation() {
+ return $this->has_or_relation;
+ }
+}