The PSQL Module Body

Data Manipulation (DML) StatementsBuilt-in Scalar Functions

The PSQL Module Body

The PSQL module body starts with an optional section that declares variables and subroutines, followed by a block of statements that run in a logical sequence, like a program.A block of statements — or compound statement — is enclosed by the BEGIN and END keywords, and is executed as a single unit of code.The main BEGIN…END block may contain any number of other BEGIN…END blocks, both embedded and sequential.Blocks can be nested to a maximum depth of 512 blocks.All statements except BEGIN and END are terminated by semicolons (‘;’).No other character is valid for use as a terminator for PSQL statements.

Switching the Terminator in isql

Here we digress a little, to explain how to switch the terminator character in the isql utility to make it possible to define PSQL modules in that environment without conflicting with isql itself, which uses the same character, semicolon (‘;’), as its own statement terminator.

isql Command `SET TERM`

Sets the terminator character(s) to avoid conflict with the terminator character in PSQL statements

Available in

ISQL only

Syntax

SET TERM new_terminator old_terminator

Table 1. `SET TERM` Parameters
Argument	Description
new_terminator	New terminator
old_terminator	Old terminator

When you write your triggers, stored procedures, stored functions or PSQL blocks in isql — either in the interactive interface or in scripts — running a SET TERM statement is needed to switch the normal isql statement terminator from the semicolon to another character or short string, to avoid conflicts with the non-changeable semicolon terminator in PSQL.The switch to an alternative terminator needs to be done before you begin defining PSQL objects or running your scripts.

The alternative terminator can be any string of characters except for a space, an apostrophe or the current terminator character(s).Any letter character(s) used will be case-sensitive.

Example

Changing the default semicolon to ‘^’ (caret) and using it to submit a stored procedure definition: character as an alternative terminator character:

SET TERM ^;

CREATE OR ALTER PROCEDURE SHIP_ORDER (
  PO_NUM CHAR(8))
AS
BEGIN
  /* Stored procedure body */
END^

/* Other stored procedures and triggers */

SET TERM ;^

/* Other DDL statements */

The PSQL Module Body

The PSQL Module Body

isql Command SET TERM

isql Command `SET TERM`