Internally, PowerBuilder processes DELETE, INSERT, and UPDATE the same way. PowerBuilder inspects these statements for variable references and replaces all variable references with a constant that conforms to the backend database's rules for that data type.
Assume you enter the following statement:
DELETE FROM employee WHERE emp_id = :emp_id_var;
In this example, emp_id_var
is
a PowerScript variable with the data type of integer that has been
defined within the scope of the script that contains the DELETE
statement.
Before the DELETE statement is executed, emp_id_var
is
assigned a value (say 691) so when the DELETE statement executes,
the database receives the following command:
DELETE FROM employee WHERE emp_id = 691;
This variable substitution technique is used for all PowerScript variable types. When you use embedded SQL, precede all PowerScript variables with a colon ( : ).