HASH( string-expression[, algorithm ] )

Following are the return types, depending on the algorithm used:

Using a hash converts the value to a byte sequence that is unique to each value passed to the function.

If the database server was started with the -fips option, the algorithm used, or the behavior, may be different, as follows:

• String functions
• -fips dbeng12/dbsrv12 server option

The following example creates a table called user_info to store information about the users of an application, including their user ID and password. One row is also inserted into the table. The password is hashed using the HASH function and the SHA256 algorithm. Storing hashed passwords in this way can be useful if you do not want to store passwords in clear text, yet you have an external application that needs to compare passwords.

CREATE TABLE user_info ( 
  employee_id   INTEGER NOT NULL PRIMARY KEY,
  user_name CHAR(80),
  user_pwd CHAR(80) );
INSERT INTO user_info 
  VALUES ( '1', 's_phillips', HASH( 'mypass', 'SHA256' ) );