Using host variables in C and C++ applications that use SQL

In C, the C statements that are used to define the host variables should be preceded by a BEGIN DECLARE SECTION statement and followed by an END DECLARE SECTION statement. If a BEGIN DECLARE SECTION and END DECLARE SECTION are specified, all host variable declarations used in SQL statements must be between the BEGIN DECLARE SECTION and the END DECLARE SECTION statements. Host variables declared using a typedef identifier also require a BEGIN DECLARE SECTION and END DECLARE SECTION; however, the typedef declarations do not need to be between these two sections.

In C++, the C++ statements that are used to define the host variables must be preceded by a BEGIN DECLARE SECTION statement and followed by an END DECLARE SECTION statement. You cannot use any variable that is not between the BEGIN DECLARE SECTION statement and the END DECLARE SECTION statement as a host variable.

All host variables within an SQL statement must be preceded by a colon (:).

The names of host variables must be unique within the program, even if the host variables are in different blocks or procedures.

An SQL statement that uses a host variable must be within the scope of the statement in which the variable was declared.

Host variables cannot be union elements.

Host variables cannot contain continuation characters within the name.