How to generate a MD5 hash

On Microsoft SQL Server
SQL> SELECT HASHBYTES('MD5', source)....

Source: varchar, nvarchar, ou varbinary, 8000 chars max.

On Oracle
PL/SQL> myhash := dbms_crypto.hash( source, dbms_crypto.HASH_MD5 );
SQL> select dbms_crypto.hash(utl_raw.cast_to_raw(source),2) ...

Source: RAW, BLOB, et CLOB. With implicite conversion, you can also use CHAR, VARCHAR2, NCHAR, NVARCHAR2 et LONG.

On Sybase
sybase> SELECT HASHBYTES('MD5', source)....

On MySQL
mysql> SELECT MD5(source) ....