IBM IMS® Explorer for VS Code

Tutorial: Editing and Executing IMS DDL

Goal

Create a DBD and PSB definition using IMS DDL statements and activate the changes in IMS from within an IMS project.

Prerequisites

  • An IMS project exists in the IMS Projects view. If you have not created one, see Creating IMS Projects.
  • An IMS database connection is configured in the IMS Connections view. If you have not created one, see Creating IMS Connections.

Part 1: Create and execute the DBD DDL

Steps

  1. In the IMS Projects view, right-click your project and select New SQL File. Enter a name for the file (for example, create-dbd).

  2. Add the following DBD DDL to the file. This example creates a database named SAMPLEDB with a tablespace and three segment tables. Adjust the names and sizes to match your design:

    DROP DATABASE SAMPLEDB;

CREATE DATABASE SAMPLEDB
  ACCESS HDAM OSAM
  RMNAME(DFSHDC40 RMANCH 3 RMRBN 3 RMBYTES 25)
  CCSID 'Cp1047'
  VERSION '1.0';

CREATE TABLESPACE SAMPLETS IN SAMPLEDB
  SIZE PRIMARY 8192;

CREATE TABLE ROOT_SEG (
  KEY_COL  CHAR(6)  INTERNALNAME KEYVAL  PRIMARY KEY,
  FIELD_1  CHAR(25) INTERNALNAME FLDONE,
  FIELD_2  CHAR(25) INTERNALNAME FLDTWO
) IN SAMPLEDB.SAMPLETS INTERNALNAME ROOTSG MAXBYTES 56;

CREATE TABLE CHILD_SEG_A (
  FIELD_3  CHAR(25) INTERNALNAME FLDA,
  FIELD_4  CHAR(25) INTERNALNAME FLDB,
  FIELD_5  CHAR(2)  INTERNALNAME FLDC,
  FIELD_6  CHAR(9)  INTERNALNAME FLDD,
  FOREIGN KEY REFERENCES ROOT_SEG
) IN SAMPLEDB.SAMPLETS INTERNALNAME CHLSGA MAXBYTES 61;

CREATE TABLE CHILD_SEG_B (
  KEY_COL_B INT          INTERNALNAME KEYB   PRIMARY KEY,
  FIELD_7   SHORT        INTERNALNAME FLDE,
  FIELD_8   DECIMAL(9,2) INTERNALNAME FLDF,
  FOREIGN KEY REFERENCES ROOT_SEG
) IN SAMPLEDB.SAMPLETS INTERNALNAME CHLSGB MAXBYTES 15;

COMMIT DDL;

    Important: All CREATE DATABASE, CREATE TABLESPACE, and CREATE TABLE statements for the DBD must be submitted together in a single execution, ending with COMMIT DDL.

  3. At the top of the SQL file, click the IMS Connection CodeLens to select the IMS database connection to execute against.

  4. Click the Execute button in the editor title bar. When prompted, confirm the IMS database connection.

  5. Review the results in the results view to confirm that COMMIT DDL completed without errors.

Part 2: Import the DBD definition

COMMIT DDL writes the DBD to the IMS catalog staging area but does not activate it in the running IMS system. The following steps activate the changes.

Steps

  1. If you are making structural changes to an existing database, stop the database before importing. In the COMMAND folder of your IMS project, create a command file and issue:

    /STOP DB SAMPLEDB

    See Executing IMS Commands for details on running commands.

  2. Issue the following type-2 command to import the staged definition and activate it in IMS:

    IMPORT DEFN SOURCE(CATALOG)

  3. After the import completes, restart the database if you stopped it:

    /START DB SAMPLEDB

  4. In the IMS Connections view, right-click the connection and select Refresh. The new database should appear in the connection tree view.

Part 3: Create and execute the PSB DDL

After the DBD is committed and imported, define the PSB in a separate SQL file.

Steps

  1. In the IMS Projects view, right-click your project and select New SQL File. Enter a name for the file (for example, create-psb).

  2. Add the following PSB DDL to the file. This example creates a program view named SAMPLEPGM that accesses the database defined in Part 1:

    CREATE PROGRAMVIEW SAMPLEPGM (
  CREATE SCHEMA PCB01 USING SAMPLEDB (
    CREATE SENSEGVIEW ROOT_SEG,
    CREATE SENSEGVIEW CHILD_SEG_A,
    CREATE SENSEGVIEW CHILD_SEG_B
  ) PROCOPT 'A' POSMULT
) LANGCOBOL;

COMMIT DDL;

    Important: All CREATE PROGRAMVIEW and CREATE SCHEMA statements for the PSB must be submitted together in a single execution, ending with COMMIT DDL.

  3. Select the IMS Connection CodeLens at the top of the file and confirm the target connection.

  4. Click Execute. Review the results view to confirm that COMMIT DDL completed without errors.

  5. Issue IMPORT DEFN SOURCE(CATALOG) again to activate the PSB definition, following the same steps as in Part 2.

Tips

  • Use separate SQL files for the DBD and PSB DDL to keep each unit of work clearly scoped and easy to rerun.
  • If a DDL execution fails, correct the statements and re-execute the entire file — all statements in the file are submitted as a single unit of work.
  • After activating changes, refresh the IMS connection to confirm the definitions are visible in the connection tree view.
  • A DBD created through DDL has only a logical definition. To allocate physical data sets for the database, use JCL on the mainframe or Zowe.

See also