Database users

Informix®

Until version 11.70.xC2, Informix database users must be created at the operating system level and must be members of the 'informix' group.

Starting with 11.70.xC2, Informix supports database-only users with the CREATE USER instruction, as in most other db servers.

Any database user must have sufficient privileges to connect and use resources of the database; user rights are defined with the GRANT command.

To get the database user associated to the current SQL connection with Informix, execute the following SQL statement:
DEFINE p_username VARCHAR(50)
SELECT USER INTO p_username FROM systables WHERE tabid=1

Dameng®

With Dameng, users must be created in the database server.

The SQL instruction to create a Dameng database user is:
CREATE USER dmguser IDENTIFIED BY "fourjs"
    PASSWORD_POLICY 0 LIMIT PASSWORD_LIFE_TIME UNLIMITED;
User permissions can be granted with the GRANT command:
GRANT DBA TO dmguser;
GRANT RESOURCE TO dmguser;

Solution

Create a Dameng database user for each Informix database user.

To get the database user associated to the current SQL connection with Dameng, execute the following SQL statement:
DEFINE p_username VARCHAR(50)
SELECT USER INTO p_username FROM dual

See Dameng documentation for more details on database user creation and authentication.