SQL Anywhere 12 CHECK constraint on column1 to not allow nulls on specific other columns

Newbie to SQL Anywhere

Table can multilple row types. How do I set a CHECK c开发者_StackOverflow社区onstraint for some columns to not be null based on value of row type column?

SQL Anywhere is strongly typed and I'm not sure it's generally a good idea to have typeless columns in your schema.

If you must you can create a pseudo-typeless column with a varchar datatype, and add a constraint that will test the string input, like so:

ALTER TABLE "DBA"."myTable" ADD "myColumn " VARCHAR(100) NULL;

ALTER TABLE "DBA"."myTable" ADD CONSTRAINT "myConstraint" 

check(
        ( ISNUMERIC( myColumn ) AND myColumn is not null ) 
     OR ( ISDATE( myColumn ) AND myColumn is not null )
     OR (...)

     );

BTW, you may wish to ask the question at http://sqla.stackexchange.com/.