Chapter 32. Stored Functions
32.1 Introduction
Stored functions show a strong resemblance to stored procedures: They are pieces of code consisting of SQL and procedural statements that are stored in the catalog and can be called from applications and SQL statements. However, a few differences exist:
• A stored function can have input parameters but does not have output parameters. The stored function itself is the output parameter. The next sections illustrate this with examples.
• After stored functions have been created, all kinds of expressions can invoke them in the same way they invoke the familiar scalar functions. Therefore, we do not call stored functions using a CALL
statement.
• Stored functions must contain a RETURN
statement. This ...
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