Database Access Commands

An CA ADS application can access the CA IDMS/DB database by using navigational DML or SQL DML.
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An CA ADS application can access the CA IDMS/DB database by using navigational DML or SQL DML.
Navigational DML
CA ADS navigational DML is used to retrieve and update database or VSAM records and perform database control functions. Navigation DML commands can be used in process logic to store, retrieve, modify, and delete data in a non-SQL defined database, using a standard subschema or a Logical Record Facility (LRF) subschema.
When using LRF, the application developer selects a predefined path that meets the dialog's data requirements and codes simple database requests in dialog process logic. Database navigation is defined in the path, not in the process.
SQL DML
In an CA ADS application, SQL DML can be used to retrieve and update data defined with:
  • Records in non-SQL defined databases (associated with an SQL schema)
  • Tables in SQL-defined databases
For more information about using SQL DML statements, see the
CA IDMS SQL Self-Training section
and the
CA IDMS SQL Programming section
.
Navigational DML and LRF commands used in the CA ADS environment are summarized in the following two tables. Documentation of command syntax appears later in this section.
Summary of Navigational DML Commands
Command
Purpose
ACCEPT
Moves database keys page information statistics from the database management system to a dialog
BIND PROCEDURE
Establishes communication from a dialog to a DBA-written procedure
COMMIT
Writes checkpoints to the journal file and releases locks held on database records
CONNECT
Connects member records to sets
DISCONNECT
Disconnects member records from sets
ERASE
Erases records from the database
FIND
Locates records in the database
GET
Copies record contents from the database to a dialog's record buffers
KEEP
Places locks on records
MODIFY
Replaces records in the database with the contents of a dialog's record buffers
OBTAIN
Locates records in the database and copies their contents to a dialog's record buffers
READY
Prepares database areas for processing
RETURN DB-KEY
Retrieves index entries without the associated record (used only with the Sequential Processing Facility and with system-owned indexed records)
ROLLBACK
Requests recovery of the database
STORE
Adds a record to the database
Summary of LRF Commands
Command
Purpose
ERASE
Deletes Logical Record Facility record occurrences
MODIFY
Changes field values in Logical Record Facility record occurrences
OBTAIN
Retrieves Logical Record Facility record occurrences
ON
Performs additional processing based on the outcome of conditional testing of Logical Record Facility record access
STORE
Stores a new occurrence of a Logical Record Facility record