Calling procedures in embedded SQL applications
You can call procedures
from embedded SQL applications by formulating and executing the
CALL
statement
with an appropriate procedure reference and parameters. You can issue
the CALL
statement either statically or dynamically
within embedded SQL applications.
However, for each programming language there are different methods to issue this command. No matter which host language, each host variable used in the procedure must be declared to match the data type which is required.
Client applications and the calling of routines exchange information with procedures through parameters and result sets. The parameters for procedures are defined by the direction the data is traveling (the parameter mode).
There are three types of parameters for procedures:
- IN parameters: data passed to the procedure.
- OUT parameters: data returned by the procedure.
- INOUT parameters: data passed to the procedure that is, during procedure execution, replaced by data to be returned from the procedure.