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dbdelta › WordPress Function
Since1.5.0
Deprecatedn/a
› dbdelta ( $queries = '', $execute = true )
Parameters: (2) |
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Returns: |
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Defined at: |
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Codex: | |
Change Log: |
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Modifies the database based on specified SQL statements.
Useful for creating new tables and updating existing tables to a new structure.Source
function dbDelta( $queries = '', $execute = true ) { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.FunctionNameInvalid global $wpdb; if ( in_array( $queries, array( '', 'all', 'blog', 'global', 'ms_global' ), true ) ) { $queries = wp_get_db_schema( $queries ); } // Separate individual queries into an array. if ( ! is_array( $queries ) ) { $queries = explode( ';', $queries ); $queries = array_filter( $queries ); } /** * Filters the dbDelta SQL queries. * * @since 3.3.0 * * @param string[] $queries An array of dbDelta SQL queries. */ $queries = apply_filters( 'dbdelta_queries', $queries ); $cqueries = array(); // Creation queries. $iqueries = array(); // Insertion queries. $for_update = array(); // Create a tablename index for an array ($cqueries) of recognized query types. foreach ( $queries as $qry ) { if ( preg_match( '|CREATE TABLE ([^ ]*)|', $qry, $matches ) ) { $cqueries[ trim( $matches[1], '`' ) ] = $qry; $for_update[ $matches[1] ] = 'Created table ' . $matches[1]; continue; } if ( preg_match( '|CREATE DATABASE ([^ ]*)|', $qry, $matches ) ) { array_unshift( $cqueries, $qry ); continue; } if ( preg_match( '|INSERT INTO ([^ ]*)|', $qry, $matches ) ) { $iqueries[] = $qry; continue; } if ( preg_match( '|UPDATE ([^ ]*)|', $qry, $matches ) ) { $iqueries[] = $qry; continue; } } /** * Filters the dbDelta SQL queries for creating tables and/or databases. * * Queries filterable via this hook contain "CREATE TABLE" or "CREATE DATABASE". * * @since 3.3.0 * * @param string[] $cqueries An array of dbDelta create SQL queries. */ $cqueries = apply_filters( 'dbdelta_create_queries', $cqueries ); /** * Filters the dbDelta SQL queries for inserting or updating. * * Queries filterable via this hook contain "INSERT INTO" or "UPDATE". * * @since 3.3.0 * * @param string[] $iqueries An array of dbDelta insert or update SQL queries. */ $iqueries = apply_filters( 'dbdelta_insert_queries', $iqueries ); $text_fields = array( 'tinytext', 'text', 'mediumtext', 'longtext' ); $blob_fields = array( 'tinyblob', 'blob', 'mediumblob', 'longblob' ); $int_fields = array( 'tinyint', 'smallint', 'mediumint', 'int', 'integer', 'bigint' ); $global_tables = $wpdb->tables( 'global' ); $db_version = $wpdb->db_version(); $db_server_info = $wpdb->db_server_info(); foreach ( $cqueries as $table => $qry ) { // Upgrade global tables only for the main site. Don't upgrade at all if conditions are not optimal. if ( in_array( $table, $global_tables, true ) && ! wp_should_upgrade_global_tables() ) { unset( $cqueries[ $table ], $for_update[ $table ] ); continue; } // Fetch the table column structure from the database. $suppress = $wpdb->suppress_errors(); $tablefields = $wpdb->get_results( "DESCRIBE {$table};" ); $wpdb->suppress_errors( $suppress ); if ( ! $tablefields ) { continue; } // Clear the field and index arrays. $cfields = array(); $indices = array(); $indices_without_subparts = array(); // Get all of the field names in the query from between the parentheses. preg_match( '|\((.*)\)|ms', $qry, $match2 ); $qryline = trim( $match2[1] ); // Separate field lines into an array. $flds = explode( "\n", $qryline ); // For every field line specified in the query. foreach ( $flds as $fld ) { $fld = trim( $fld, " \t\n\r\0\x0B," ); // Default trim characters, plus ','. // Extract the field name. preg_match( '|^([^ ]*)|', $fld, $fvals ); $fieldname = trim( $fvals[1], '`' ); $fieldname_lowercased = strtolower( $fieldname ); // Verify the found field name. $validfield = true; switch ( $fieldname_lowercased ) { case '': case 'primary': case 'index': case 'fulltext': case 'unique': case 'key': case 'spatial': $validfield = false; /* * Normalize the index definition. * * This is done so the definition can be compared against the result of a * `SHOW INDEX FROM $table_name` query which returns the current table * index information. */ // Extract type, name and columns from the definition. preg_match( '/^ (?P<index_type> # 1) Type of the index. PRIMARY\s+KEY|(?:UNIQUE|FULLTEXT|SPATIAL)\s+(?:KEY|INDEX)|KEY|INDEX ) \s+ # Followed by at least one white space character. (?: # Name of the index. Optional if type is PRIMARY KEY. `? # Name can be escaped with a backtick. (?P<index_name> # 2) Name of the index. (?:[0-9a-zA-Z$_-]|[\xC2-\xDF][\x80-\xBF])+ ) `? # Name can be escaped with a backtick. \s+ # Followed by at least one white space character. )* \( # Opening bracket for the columns. (?P<index_columns> .+? # 3) Column names, index prefixes, and orders. ) \) # Closing bracket for the columns. $/imx', $fld, $index_matches ); // Uppercase the index type and normalize space characters. $index_type = strtoupper( preg_replace( '/\s+/', ' ', trim( $index_matches['index_type'] ) ) ); // 'INDEX' is a synonym for 'KEY', standardize on 'KEY'. $index_type = str_replace( 'INDEX', 'KEY', $index_type ); // Escape the index name with backticks. An index for a primary key has no name. $index_name = ( 'PRIMARY KEY' === $index_type ) ? '' : '`' . strtolower( $index_matches['index_name'] ) . '`'; // Parse the columns. Multiple columns are separated by a comma. $index_columns = array_map( 'trim', explode( ',', $index_matches['index_columns'] ) ); $index_columns_without_subparts = $index_columns; // Normalize columns. foreach ( $index_columns as $id => &$index_column ) { // Extract column name and number of indexed characters (sub_part). preg_match( '/ `? # Name can be escaped with a backtick. (?P<column_name> # 1) Name of the column. (?:[0-9a-zA-Z$_-]|[\xC2-\xDF][\x80-\xBF])+ ) `? # Name can be escaped with a backtick. (?: # Optional sub part. \s* # Optional white space character between name and opening bracket. \( # Opening bracket for the sub part. \s* # Optional white space character after opening bracket. (?P<sub_part> \d+ # 2) Number of indexed characters. ) \s* # Optional white space character before closing bracket. \) # Closing bracket for the sub part. )? /x', $index_column, $index_column_matches ); // Escape the column name with backticks. $index_column = '`' . $index_column_matches['column_name'] . '`'; // We don't need to add the subpart to $index_columns_without_subparts $index_columns_without_subparts[ $id ] = $index_column; // Append the optional sup part with the number of indexed characters. if ( isset( $index_column_matches['sub_part'] ) ) { $index_column .= '(' . $index_column_matches['sub_part'] . ')'; } } // Build the normalized index definition and add it to the list of indices. $indices[] = "{$index_type} {$index_name} (" . implode( ',', $index_columns ) . ')'; $indices_without_subparts[] = "{$index_type} {$index_name} (" . implode( ',', $index_columns_without_subparts ) . ')'; // Destroy no longer needed variables. unset( $index_column, $index_column_matches, $index_matches, $index_type, $index_name, $index_columns, $index_columns_without_subparts ); break; } // If it's a valid field, add it to the field array. if ( $validfield ) { $cfields[ $fieldname_lowercased ] = $fld; } } // For every field in the table. foreach ( $tablefields as $tablefield ) { $tablefield_field_lowercased = strtolower( $tablefield->Field ); $tablefield_type_lowercased = strtolower( $tablefield->Type ); $tablefield_type_without_parentheses = preg_replace( '/' . '(.+)' // Field type, e.g. `int`. . '\(\d*\)' // Display width. . '(.*)' // Optional attributes, e.g. `unsigned`. . '/', '$1$2', $tablefield_type_lowercased ); // Get the type without attributes, e.g. `int`. $tablefield_type_base = strtok( $tablefield_type_without_parentheses, ' ' ); // If the table field exists in the field array... if ( array_key_exists( $tablefield_field_lowercased, $cfields ) ) { // Get the field type from the query. preg_match( '|`?' . $tablefield->Field . '`? ([^ ]*( unsigned)?)|i', $cfields[ $tablefield_field_lowercased ], $matches ); $fieldtype = $matches[1]; $fieldtype_lowercased = strtolower( $fieldtype ); $fieldtype_without_parentheses = preg_replace( '/' . '(.+)' // Field type, e.g. `int`. . '\(\d*\)' // Display width. . '(.*)' // Optional attributes, e.g. `unsigned`. . '/', '$1$2', $fieldtype_lowercased ); // Get the type without attributes, e.g. `int`. $fieldtype_base = strtok( $fieldtype_without_parentheses, ' ' ); // Is actual field type different from the field type in query? if ( $tablefield->Type !== $fieldtype ) { $do_change = true; if ( in_array( $fieldtype_lowercased, $text_fields, true ) && in_array( $tablefield_type_lowercased, $text_fields, true ) ) { if ( array_search( $fieldtype_lowercased, $text_fields, true ) < array_search( $tablefield_type_lowercased, $text_fields, true ) ) { $do_change = false; } } if ( in_array( $fieldtype_lowercased, $blob_fields, true ) && in_array( $tablefield_type_lowercased, $blob_fields, true ) ) { if ( array_search( $fieldtype_lowercased, $blob_fields, true ) < array_search( $tablefield_type_lowercased, $blob_fields, true ) ) { $do_change = false; } } if ( in_array( $fieldtype_base, $int_fields, true ) && in_array( $tablefield_type_base, $int_fields, true ) && $fieldtype_without_parentheses === $tablefield_type_without_parentheses ) { /* * MySQL 8.0.17 or later does not support display width for integer data types, * so if display width is the only difference, it can be safely ignored. * Note: This is specific to MySQL and does not affect MariaDB. */ if ( version_compare( $db_version, '8.0.17', '>=' ) && ! str_contains( $db_server_info, 'MariaDB' ) ) { $do_change = false; } } if ( $do_change ) { // Add a query to change the column type. $cqueries[] = "ALTER TABLE {$table} CHANGE COLUMN `{$tablefield->Field}` " . $cfields[ $tablefield_field_lowercased ]; $for_update[ $table . '.' . $tablefield->Field ] = "Changed type of {$table}.{$tablefield->Field} from {$tablefield->Type} to {$fieldtype}"; } } // Get the default value from the array. if ( preg_match( "| DEFAULT '(.*?)'|i", $cfields[ $tablefield_field_lowercased ], $matches ) ) { $default_value = $matches[1]; if ( $tablefield->Default !== $default_value ) { // Add a query to change the column's default value $cqueries[] = "ALTER TABLE {$table} ALTER COLUMN `{$tablefield->Field}` SET DEFAULT '{$default_value}'"; $for_update[ $table . '.' . $tablefield->Field ] = "Changed default value of {$table}.{$tablefield->Field} from {$tablefield->Default} to {$default_value}"; } } // Remove the field from the array (so it's not added). unset( $cfields[ $tablefield_field_lowercased ] ); } else { // This field exists in the table, but not in the creation queries? } } // For every remaining field specified for the table. foreach ( $cfields as $fieldname => $fielddef ) { // Push a query line into $cqueries that adds the field to that table. $cqueries[] = "ALTER TABLE {$table} ADD COLUMN $fielddef"; $for_update[ $table . '.' . $fieldname ] = 'Added column ' . $table . '.' . $fieldname; } // Index stuff goes here. Fetch the table index structure from the database. $tableindices = $wpdb->get_results( "SHOW INDEX FROM {$table};" ); if ( $tableindices ) { // Clear the index array. $index_ary = array(); // For every index in the table. foreach ( $tableindices as $tableindex ) { $keyname = strtolower( $tableindex->Key_name ); // Add the index to the index data array. $index_ary[ $keyname ]['columns'][] = array( 'fieldname' => $tableindex->Column_name, 'subpart' => $tableindex->Sub_part, ); $index_ary[ $keyname ]['unique'] = ( '0' === $tableindex->Non_unique ) ? true : false; $index_ary[ $keyname ]['index_type'] = $tableindex->Index_type; } // For each actual index in the index array. foreach ( $index_ary as $index_name => $index_data ) { // Build a create string to compare to the query. $index_string = ''; if ( 'primary' === $index_name ) { $index_string .= 'PRIMARY '; } elseif ( $index_data['unique'] ) { $index_string .= 'UNIQUE '; } if ( 'FULLTEXT' === strtoupper( $index_data['index_type'] ) ) { $index_string .= 'FULLTEXT '; } if ( 'SPATIAL' === strtoupper( $index_data['index_type'] ) ) { $index_string .= 'SPATIAL '; } $index_string .= 'KEY '; if ( 'primary' !== $index_name ) { $index_string .= '`' . $index_name . '`'; } $index_columns = ''; // For each column in the index. foreach ( $index_data['columns'] as $column_data ) { if ( '' !== $index_columns ) { $index_columns .= ','; } // Add the field to the column list string. $index_columns .= '`' . $column_data['fieldname'] . '`'; } // Add the column list to the index create string. $index_string .= " ($index_columns)"; // Check if the index definition exists, ignoring subparts. $aindex = array_search( $index_string, $indices_without_subparts, true ); if ( false !== $aindex ) { // If the index already exists (even with different subparts), we don't need to create it. unset( $indices_without_subparts[ $aindex ] ); unset( $indices[ $aindex ] ); } } } // For every remaining index specified for the table. foreach ( (array) $indices as $index ) { // Push a query line into $cqueries that adds the index to that table. $cqueries[] = "ALTER TABLE {$table} ADD $index"; $for_update[] = 'Added index ' . $table . ' ' . $index; } // Remove the original table creation query from processing. unset( $cqueries[ $table ], $for_update[ $table ] ); } $allqueries = array_merge( $cqueries, $iqueries ); if ( $execute ) { foreach ( $allqueries as $query ) { $wpdb->query( $query ); } } return $for_update; }