SQL table definition

Informix®

Informix supports primary key, unique, foreign key, default and check constraints.

The constraint naming syntax is different in Informix and most other databases: Informix expects the constraint name after the constraint definition:

CREATE TABLE emp (
  ...
  emp_code CHAR(10) UNIQUE CONSTRAINT pk_emp,
  ...
)

While other SQL database brands require to specify the constraint name before the constraint definition:

CREATE TABLE emp (
   ... 
   emp_code CHAR(10) CONSTRAINT pk_emp UNIQUE, 
   ...
)

Dameng®

Dameng supports primary key, unique, foreign key, default and check constraints.

Constraint naming

The constraint naming clause must be placed before the constraint specification:

CREATE TABLE customer ( cust_id INTEGER CONSTRAINT pk1 PRIMARY KEY, ... )

The database interface does not convert constraint naming expressions when creating tables from BDL programs. Review the database creation scripts to adapt the constraint naming clauses for Dameng.