A new built-in function RAISE_ERROR('diagnostic-string') is needed to

let mysql users fail current statement with the desired

diagnostic-string error message and reserved sql error code.

DB2 does in its' RAISE_ERROR() function, where the function accepts

parameters of sql state and msg, and Oracle's RAISE_APPLICATION_ERROR

has similar function.

In our implementation, raise_error() accepts parameter of msg and

optional sql state, both are strings. NULL value input is not allowed

for either one, and only validate sql state is allowed.

Here are samples:

--error ER_SP_BAD_SQLSTATE

select raise_error(NULL, 'null sql state not allowed');

--error ER_MALFORMED_MESSAGE select raise_error('70001', NULL);

--error ER_SP_BAD_SQLSTATE

select raise_error('00001', 'invalid sql state');

--error ER_SP_BAD_SQLSTATE

select raise_error('666666', 'length of sql state exceeds 5');

--error ER_INTENTIONAL_ERROR

select raise_error('70001', 'this is a sample error msg');

--error ER_INTENTIONAL_ERROR

select raise_error('this is a sample error msg');

--error ER_INTENTIONAL_ERROR

select raise_error('only error message applied');