DECLARE condition_name CONDITION FOR condition_value

condition_value:
    SQLSTATE [VALUE] sqlstate_value
  | mysql_error_code

The DECLARE ... CONDITION statement defines a named error condition. It specifies a condition that needs specific handling and associates a name with that condition. The name can be referred to in a subsequent DECLARE ... HANDLER statement. For an example, see Section 12.7.4.2, “DECLARE for Handlers”.

A condition_value for DECLARE ... CONDITION can be an SQLSTATE value (a 5-character string literal) or a MySQL error code (a number). You should not use SQLSTATE value '00000' or MySQL error code 0, because those indicate success rather than an error condition. For a list of SQLSTATE values and MySQL error codes, see Section C.3, “Server Error Codes and Messages”.