HTML Examples/WP.iso/wordpress2/wp-includes/class-wp-meta-query.php

PHP Script | 2017-10-02 | 21.7 KB | 731 lines

<?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;
    }
}