check_column( string $table_name, string $col_name, string $col_type, bool $is_null = null, mixed $key = null, mixed $default_value = null, mixed $extra = null ): bool
- Since
- 1.0.0
- Source
wp-admin/install-helper.php:183
Description
Uses the SQL DESC for retrieving the table info for the column. It will help understand the parameters, if you do more research on what column information is returned by the SQL statement. Pass in null to skip checking that criteria.
Column names returned from DESC table are case sensitive and are as listed:
- Field
- Type
- Null
- Key
- Default
- Extra
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.
$col_namestring- Table column name.
$col_typestring- Table column type.
$is_nullbooloptional- Check is null.Default:
null $keymixedoptional- Key info.Default:
null $default_valuemixedoptional- Default value.Default:
null $extramixedoptional- Extra value.Default:
null
Return value
bool- True, if matches. False, if not matching.
Performance profile
How much work a call to check_column() 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
- Scales with input
- Instructions
- 17–53
- Plugin surface
- None
- Called by
- 0
Reaches the database via ->get_results().
The body loops, so the work grows with what you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 57.
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_results()called directly
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost check_column() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 17–53 | ->get_results() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 57 instructions, 17–53 executed per call, 14 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 check_column( $table_name, $col_name, $col_type, $is_null = null, $key = null, $default_value = null, $extra = null ) { global $wpdb; $diffs = 0; // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names. $results = $wpdb->get_results( "DESC $table_name" ); foreach ( $results as $row ) { if ( $row->Field === $col_name ) { // Got our column, check the params. if ( ( null !== $col_type ) && ( $row->Type !== $col_type ) ) { ++$diffs; } if ( ( null !== $is_null ) && ( $row->Null !== $is_null ) ) { ++$diffs; } if ( ( null !== $key ) && ( $row->Key !== $key ) ) { ++$diffs; } if ( ( null !== $default_value ) && ( $row->Default !== $default_value ) ) { ++$diffs; } if ( ( null !== $extra ) && ( $row->Extra !== $extra ) ) { ++$diffs; } if ( $diffs > 0 ) { return false; } return true; } // End if found our column. } 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 7.0.4 tag, from
src/wp-admin/install-helper.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.