The pre_get_col_charset filter allows you to modify the column charset value before the database is checked, potentially bypassing the need to check the database.
Usage
add_filter('pre_get_col_charset', 'your_custom_function', 10, 3);
function your_custom_function($charset, $table, $column) {
// your custom code here
return $charset;
}
Parameters
$charset(string|null): The character set to use. Default isnull.$table(string): The name of the table being checked.$column(string): The name of the column being checked.
More information
See WordPress Developer Resources: pre_get_col_charset
Examples
Set a custom charset for a specific table and column
In this example, we set a custom charset for the content column of the my_custom_table.
add_filter('pre_get_col_charset', 'set_custom_charset', 10, 3);
function set_custom_charset($charset, $table, $column) {
if ($table == 'my_custom_table' && $column == 'content') {
$charset = 'utf8mb4';
}
return $charset;
}
Set a custom charset for all tables
In this example, we set a custom charset for all tables in the database.
add_filter('pre_get_col_charset', 'set_charset_for_all_tables', 10, 3);
function set_charset_for_all_tables($charset, $table, $column) {
$charset = 'utf8';
return $charset;
}
Set a custom charset for all columns with a specific name
In this example, we set a custom charset for all columns named description.
add_filter('pre_get_col_charset', 'set_charset_for_description_columns', 10, 3);
function set_charset_for_description_columns($charset, $table, $column) {
if ($column == 'description') {
$charset = 'utf8mb4';
}
return $charset;
}
Set a custom charset based on a condition
In this example, we set a custom charset based on a specific condition.
add_filter('pre_get_col_charset', 'conditionally_set_charset', 10, 3);
function conditionally_set_charset($charset, $table, $column) {
if (your_custom_condition($table, $column)) {
$charset = 'utf8mb4';
}
return $charset;
}
Bypass charset check for specific tables
In this example, we bypass the charset check for specific tables by returning a non-null value.
add_filter('pre_get_col_charset', 'bypass_charset_check', 10, 3);
function bypass_charset_check($charset, $table, $column) {
$bypass_tables = array('table1', 'table2', 'table3');
if (in_array($table, $bypass_tables)) {
$charset = 'utf8';
}
return $charset;
}