Functions return information from the database and are allowed anywhere an expression is allowed.
Remember the following when using functions with Sybase IQ:
Unless otherwise stated, any function that receives the NULL value as a parameter returns a NULL value.
If you omit the FROM clause, or if all tables in the query are in the SYSTEM dbspace, Adaptive Server Anywhere processes the query, instead of Sybase IQ, and might behave differently, especially with regard to syntactic and semantic restrictions and the effects of option settings. See the Adaptive Server Anywhere documentation for rules that might apply to processing.
If you have a query that does not require a FROM clause, you can force Sybase IQ to process the query by adding the clause “FROM iq_dummy,” where iq_dummy is a one-row, one-column table that you create in your database.
