Declaring Host Variables

Variables used in SQL commands in an executable section are known as host variables. All host variables used in a program must be declared in a declaration part. In a subprogram, the host variables must be declared in the declaration section of any level of a procedure -- but not in the global declaration part. The host variable declarations must appear between the two following SQL commands:

   EXEC SQL BEGIN DECLARE SECTION;

    .

    .  Host variables are declared here

    .  in Pascal data declarations.



   EXEC SQL END DECLARE SECTION;

In Figure 3-1, host variable declarations start at 2.

You can put only one such declaration section in a program, and all host variables must be declared between the BEGIN/END DECLARE SECTION commands in a declaration part.

The SELECT command shown at 8 in Figure 3-1 uses three host variables for data, one for each of the columns in the PurchDB.Parts table. When used in an embedded SQL command, host variables are preceded with a colon, as follows:

:PartNumber

:PartName

:SalesPrice

For detailed information regarding host variables, see the chapter, "Host Variables."