Programming User Exits

CA Dataquery provides user exits to allow you to establish routines that will occur at predetermined points in the CA Dataquery processing.

Prerequisites to Using User Exits

To make any of the exits presented in this chapter available for use, you must:

Write the user exit according to the directions presented in this chapter.
Take one of the following actions:
- Code the appropriate System Option Table DQOPTLST parameters from the following list according to the directions provided in this document.

Batch Submit Exit	SUBEXIT=
Query Validation Exit	VALEXIT=
Signon/off Exit Batch	SXBEXIT=
Signon/off Exit Online	SONEXIT=
User-Defined Functions Exit	UDFMOD=
Data Stream Input Exit	DSIEXIT=
Data Stream Output Exit	DSOEXIT=
DBID Exit Batch	CDBXITB=
DBID Exit Online	CDBXITO=
Data Exit	DATAXIT=
Online Output Exit	OUTXITO=
Batch Output Exit	OUTXITB=
Batch Line Printer Exit	BTCHLPX=

Link the exit module with the DQSYSTBL module:

Batch Line Printer Exit	BATCHLP
Network Print Exit	DQEXIT

Available User Exits

Name of User Exit	Description	Location of Details
Batch Line Printer Exit	This exit enables you to control output in DQBATCH. This exit must do all output to the system line printer. CA Dataquery passes the length and address of each line to be printed, and a top of page indicator to the user-written program. This allows nonstandard control codes to be inserted into the print lines to accommodate special printers.	Chapter 47, "Batch Line Printer Exit"
Batch Submit Exit	This exit enables you to inspect and modify the JCL used for batch query execution initiated through the online submit function. CA Dataquery passes the user name, user password, and the JCL member that is to be used to submit the query to the user-written program when a query is submitted for execution using the Batch Execution panel. This exit provides you with the opportunity to validate the user or modify the JCL member.	CICS: Batch Submit Exit in CICS
DBID Exit	In batch or online, when a query is validated, this exit is called once for each table named in the query and has the opportunity to change the CA Datacom/DB ID of any table. Provides CA Dataquery with the correct CA Datacom/DB identifier prior to execution of a DQL Language query. When query validation is complete, CA Dataquery gives control to this exit and passes the following to the exit: CA Datacom Datadictionary entity-name CA Dataquery user identification CA Datacom/DB table name CA Datacom/DB database ID The exit can change the CA Datacom/DB table name causing CA Dataquery to update its processing control blocks to reflect the new information. This process occurs one time for every table for each query.	Chapter 49, "DBID Exit"
Data Exit	This exit is called every time CA Dataquery is ready to include a row in the found set of a query. It can reject the row, preventing its inclusion in the set. In online and batch, passes user's name, 3-character CA Datacom/DB name for the table being accessed, DBID, and the row itself. The exit may examine the row and return an indicator as to whether the user should have access to the row.	Chapter 50, "Data Exit"
Data Stream Input Exit	The Data Stream Input exit receives control when an input data stream is received by CA Dataquery from a terminal. It can examine and modify the data stream.	Chapter 51, "Data Stream Input Exit"
Data Stream Output Exit	The exit can inspect and modify the data stream in place but must not change its location or length. The Data Stream Output exit receives control just before CA Dataquery writes a data stream to a terminal. It can inspect and modify the data stream.	Chapter 52, "Data Stream Output Exit"
Network Printer Exit	This exit enables you to inspect and modify the print lines produced by an online query whose output destination is a network printer. CA Dataquery passes the address where the exit should build the data stream, the address of the image where the data stream should be built, the address of a flag that indicates whether a page ejection should occur and the number of columns per row in the data stream image to the user-written program. This allows nonstandard control codes to be inserted into the print lines to accommodate special printers.	Chapter 53, "Network Printer Exit"
Output Exit	This exit allows you to access individual rows of output data before the output is printed.	Chapter 48, "Output Exit"
Query Validation Exit	This exit enables you to make changes to a query before the query is executed. CA Dataquery passes the query and user name that has been submitted for execution to the user-written program. The program may limit the number of rows searched by a query on a particular CA Datacom/DB table. This is an effective technique for enforcing site standards on queries.	Chapter 43, "Query Validation Exit"
Signon/off Exit	In batch and online, passes the user ID, password, and time of signon to the user-written program. The program can use this data to further validate the user, to track how frequently the user is accessing CA Dataquery, to enhance security, and so on. This exit must be used if CA Dataquery is to communicate with other security packages.	Chapter 45, "Sign-on/off Exit"
User-Defined Functions Exit	This exit enables you to manipulate the data resulting from a query execution by performing mathematical procedures in the form of SET statements. CA Dataquery passes the retrieved data resulting from a query execution to a user-written program.	Chapter 44, "User-Defined Functions Exit"