maybe_create_table( string $table_name, string $create_ddl ): bool
- Since
- 1.0.0
- Source
wp-admin/includes/upgrade.php:2655
Description
This method checks for an existing database table and creates a new one if it's not already present. It doesn't rely on MySQL's "IF NOT EXISTS" statement, but chooses to query all tables first and then run the SQL statement creating the table.
Compatibility
- WordPress
- since 1.0.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$table_namestring- Database table name.
$create_ddlstring- SQL statement to create table.
Return value
bool- True on success or if the table already exists. False on failure.
Performance profile
How much work a call to maybe_create_table() 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
- Scaling
- Constant
- Instructions
- 17–25
- Plugin surface
- None
- Called by
- 0
Reaches the database via ->get_var().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 27.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- sqldatabase query
->get_var()called directly
What one call costs · 2 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost maybe_create_table() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
$table_name === false | 17 | ->esc_like(), ->prepare(), ->get_var() |
$table_name !== false | 25 | ->esc_like(), ->prepare(), ->get_var(), ->query(), ->get_var() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 27 instructions, 17–25 executed per call, 2 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Source code
function maybe_create_table( $table_name, $create_ddl ) { global $wpdb; $query = $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table_name ) ); if ( $wpdb->get_var( $query ) === $table_name ) { return true; } // Didn't find it, so try to create it. $wpdb->query( $create_ddl ); // We cannot directly tell that whether this succeeded! if ( $wpdb->get_var( $query ) === $table_name ) { return true; } return false;}Changelog
Introduced in 1.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.9.7 tag, from
src/wp-admin/includes/upgrade.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.