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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
SELECT statementUse the SELECT statement to retrieve values from a database or from an SPL or collection variable. A SELECT operation is called a query.
Projection ClauseThe Projection clause (sometimes called the Select clause) specifies a list of database objects or expressions to retrieve, and can set restrictions on qualifying rows. (The select list is sometimes also called the projection list.)
Expressions in the Select List
Selecting User-Defined Function Expressions

Selecting User-Defined Function Expressions

User-defined functions extend the range of functions that are available to you and allow you to perform a subquery on each row that you select.

The following example calls the get_orders( ) user-defined function for each customer_num and displays the returned value under the n_orders label:

SELECT customer_num, lname, get_orders(customer_num) n_orders
      FROM customer;

If an SPL routine in a SELECT statement contains certain SQL statements, the database server returns an error. For information on which SQL statements cannot be used in an SPL routine that is called within a query, see Restrictions on SPL Routines in Data-Manipulation Statements.

For the complete syntax of user-defined function expressions, see User-Defined Functions.