MsSQL to MySQL function conversion - mysql

Question

So I am trying to convert a function I created in MSSQL to MYSQL. The way I have it written in MSSQL is:
ALTER function FormatDate(#date datetime) returns varchar(10)
begin
declare #salida varchar(10)
if (#date != '') and (#date != '01/01/1900')
begin
declare #day varchar(2)
set #day = cast(day(#date) as varchar)
if len(#day) = 1
set #day = '0' + #day
declare #month varchar(2)
set #month = cast(month(#date) as varchar)
if len(#month) = 1
set #month = '0' + #month
select #salida = #month + '/' + #day + '/' + cast(year(#date) as varchar)
end
else
set #salida = null
return #salida
end
I am trying to convert that function into a MYSQL function. I tried this:
Delimiter $$
create function FormatDate(tiempo datetime)
RETURNS varchar(10)
READS SQL DATA
BEGIN
declare salida varchar(10);
if ((tiempo != '') and (tiempo != '01/01/1900')) then
BEGIN
declare dia varchar(2);
set dia = cast(day(tiempo) as varchar);
if len(dia) = 1 then
set dia = '0' + dia;
END IF;
declare mes varchar(2);
set mes = cast(month(tiempo) as varchar);
if len(mes) = 1 then
set mes = '0' + mes;
END IF;
select salida = mes + '/' + dia + '/' + cast(year(tiempo) as varchar);
else
set salida = null;
END; End if;
return (salida);
END $$
Delimiter ;
but I get an error when I try to execute that code.
This is the error I am getting:
Error Code: 1064. You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near 'varchar);
if len(dia) = 1 then
' at line 14
Can someone please help me convert this MSSQL function into a MYSQL function?

Answer 1

The function to determine a strings lenght in MySQL is called LENGTH(), not len()
http://dev.mysql.com/doc/refman/5.1/en/string-functions.html#function_length
MORE:
I added a working version of your function below. But please note that the built-in function DATE_FORMAT() does exactly what you want:
mysql> SELECT FormatDate( NOW() ), DATE_FORMAT( NOW(), "%m/%d/%Y" );
+---------------------+----------------------------------+
| FormatDate( NOW() ) | DATE_FORMAT( NOW(), "%m/%d/%Y" ) |
+---------------------+----------------------------------+
| 07/15/2011 | 07/15/2011 |
+---------------------+----------------------------------+
You should either use it or replace your function body with a call of that function. Here is, however, a MySQL compatible version of your function:
DELIMITER $$
CREATE FUNCTION `FormatDate`(tiempo datetime) RETURNS varchar(10)
READS SQL DATA
BEGIN
DECLARE salida VARCHAR(10);
DECLARE dia VARCHAR(2);
DECLARE mes VARCHAR(2);
IF ( (tiempo <> '') AND ( tiempo <> '01/01/1900' ) ) THEN
SET dia := CAST( DAY( tiempo ) AS CHAR );
IF LENGTH( dia ) = 1 THEN
SET dia := CONCAT( '0', dia);
END IF;
SET mes := CAST( MONTH( tiempo ) AS CHAR );
IF LENGTH( mes ) = 1 THEN
SET mes := CONCAT( '0', mes );
END IF;
SET salida := CONCAT_WS( '/', mes, dia, CAST( YEAR( tiempo ) AS CHAR ) );
ELSE
SET salida := NULL;
END IF;
RETURN salida;
END $$
DELIMITER ;