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Source code

function maybe_drop_column($table_name, $column_name, $drop_ddl) {

	global $wpdb;

	foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {

		if ($column == $column_name) {

			//found it try to drop it.

			$wpdb->query($drop_ddl);

			// we cannot directly tell that whether this succeeded!

			foreach ($wpdb->get_col("DESC $table_name",0) as $column ) {

				if ($column == $column_name) {

					return false;

				}

			}

		}

	}

	// else didn't find it

	return true;

}