wpdb::query( string $query ): int|bool

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$querystring

Database query.

Return value

int|bool

Boolean true for CREATE, ALTER, TRUNCATE and DROP queries. Number of rows affected/selected for all other queries. Boolean false on error.

Performance profile

How much work a call to wpdb::query() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via wpdb::query().

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

6–93

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 151.

Plugin surface

1 hook

Third-party callbacks on 'query' run inside this call, and their cost is not bounded by anything here.

Called by

7

7 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• sqldatabase querywpdb::query()this function does it
• hookthird-party callbacksapply_filters()called directly

Further down the call graph this can also reach query, option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 129 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wpdb::query() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while wpdb::query() runs, in this order:

1. 1
   apply_filters( query )filterline 2228 (+16 into the body)

   Filters the database query.

Uses · 9

• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_load_translations_early()Attempts an early load of translations.
• __()Retrieves the translation of $text.
• wpdb::flush()Kills cached query results.
• wpdb::check_ascii()Checks if a string is ASCII.
• wpdb::strip_invalid_text_from_query()Strips any invalid characters from the query.
• wpdb::_do_query()Internal function to perform the mysqli_query() call.
• wpdb::check_connection()Checks that the connection to the database is still up. If not, try to reconnect.
• wpdb::print_error()Prints SQL/DB error.

Used by · 7

• wpdb::_insert_replace_helper()Helper function for insert and replace.
• wpdb::delete()Deletes a row in the table.
• wpdb::get_col()Retrieves one column from the database.
• wpdb::get_results()Retrieves an entire SQL result set from the database (i.e., many rows).
• wpdb::get_row()Retrieves one row from the database.
• wpdb::get_var()Retrieves one value from the database.
• wpdb::update()Updates a row in the table.

Source code

View on Trac ↗View on GitHub ↗

2212	public function query( $query ) {2213		if ( ! $this->ready ) {2214			$this->check_current_query = true;2215			return false;2216		}2217 2218		/**2219		 * Filters the database query.2220		 *2221		 * Some queries are made before the plugins have been loaded,2222		 * and thus cannot be filtered with this method.2223		 *2224		 * @since 2.1.02225		 *2226		 * @param string $query Database query.2227		 */2228		$query = apply_filters( 'query', $query );2229 2230		if ( ! $query ) {2231			$this->insert_id = 0;2232			return false;2233		}2234 2235		$this->flush();2236 2237		// Log how the function was called.2238		$this->func_call = "\$db->query(\"$query\")";2239 2240		// If we're writing to the database, make sure the query will write safely.2241		if ( $this->check_current_query && ! $this->check_ascii( $query ) ) {2242			$stripped_query = $this->strip_invalid_text_from_query( $query );2243			/*2244			 * strip_invalid_text_from_query() can perform queries, so we need2245			 * to flush again, just to make sure everything is clear.2246			 */2247			$this->flush();2248			if ( $stripped_query !== $query ) {2249				$this->insert_id  = 0;2250				$this->last_query = $query;2251 2252				wp_load_translations_early();2253 2254				$this->last_error = __( 'WordPress database error: Could not perform query because it contains invalid data.' );2255 2256				return false;2257			}2258		}2259 2260		$this->check_current_query = true;2261 2262		// Keep track of the last query for debug.2263		$this->last_query = $query;2264 2265		$this->_do_query( $query );2266 2267		// Database server has gone away, try to reconnect.2268		$mysql_errno = 0;2269 2270		if ( $this->dbh instanceof mysqli ) {2271			$mysql_errno = mysqli_errno( $this->dbh );2272		} else {2273			/*2274			 * $dbh is defined, but isn't a real connection.2275			 * Something has gone horribly wrong, let's try a reconnect.2276			 */2277			$mysql_errno = 2006;2278		}2279 2280		if ( empty( $this->dbh ) || 2006 === $mysql_errno ) {2281			if ( $this->check_connection() ) {2282				$this->_do_query( $query );2283			} else {2284				$this->insert_id = 0;2285				return false;2286			}2287		}2288 2289		// If there is an error then take note of it.2290		if ( $this->dbh instanceof mysqli ) {2291			$this->last_error = mysqli_error( $this->dbh );

Changelog

Introduced in 0.71. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.0.4 tag, from src/wp-includes/class-wpdb.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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