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maybe_drop_column › WordPress Function

Since1.0.0
已弃用n/a
› maybe_drop_column ( $table_name, $column_name, $drop_ddl )
参数: (3)
  • (string) $table_name Database table name.
    Required: Yes
  • (string) $column_name Table column name.
    Required: Yes
  • (string) $drop_ddl SQL statement to drop column.
    Required: Yes
返回:
  • (bool) True on success or if the column doesn't exist. False on failure.
定义在:
文档:

Drops column from database table, if it exists.



Related Functions: maybe_add_column, _maybe_update_plugins, _maybe_update_core, get_hidden_columns, parent_dropdown

源码 

function maybe_drop_column( $table_name, $column_name, $drop_ddl ) {
	global $wpdb;

	// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
	foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
		if ( $column === $column_name ) {

			// Found it, so try to drop it.
			// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- No applicable variables for this query.
			$wpdb->query( $drop_ddl );

			// We cannot directly tell whether this succeeded!
			// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Cannot be prepared. Fetches columns for table names.
			foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
				if ( $column === $column_name ) {
					return false;
				}
			}
		}
	}

	// Else didn't find it.
	return true;
}