maybe_drop_column

Drop column from database table, if it exists.

Description

maybe_drop_column( (string) $table_name, (string) $column_name, (string) $drop_ddl ); 

Parameters (3)

0. $table_name (string)
The table name.
1. $column_name (string)
The column name.
2. $drop_ddl (string)
SQL statement to drop column.

Usage

  1. if ( !function_exists( 'maybe_drop_column' ) ) { 
  2.     require_once ABSPATH . '/wp-admin/install-helper.php'; 
  3. } 
  4.   
  5. // The table name. 
  6. $table_name = ''; 
  7.   
  8. // The column name. 
  9. $column_name = ''; 
  10.   
  11. // SQL statement to drop column. 
  12. $drop_ddl = ''; 
  13.   
  14. // NOTICE! Understand what this does before running. 
  15. $result = maybe_drop_column($table_name, $column_name, $drop_ddl); 
  16.     

Defined (1)

The function is defined in the following location(s).

/wp-admin/install-helper.php  
  1. function maybe_drop_column($table_name, $column_name, $drop_ddl) { 
  2.     global $wpdb; 
  3.     foreach ($wpdb->get_col("DESC $table_name", 0) as $column ) { 
  4.         if ($column == $column_name) { 
  5.  
  6.             // Found it, so try to drop it. 
  7.             $wpdb->query($drop_ddl); 
  8.  
  9.             // We cannot directly tell that whether this succeeded! 
  10.             foreach ($wpdb->get_col("DESC $table_name", 0) as $column ) { 
  11.                 if ($column == $column_name) { 
  12.                     return false; 
  13.                 } 
  14.             } 
  15.         } 
  16.     } 
  17.     // Else didn't find it. 
  18.     return true; 
  19. }