|The IMS Option Interface||Editing IMS Databases|
This chapter describes the IMS-specific aspects of developing applications with Mainframe Express. For information about using the Mainframe Express IDE, creating projects and compiling and debugging applications see the chapters The Mainframe Express Interface, Developing Applications with Mainframe Express and Workgrouping in this User's Guide.
You must specify that the project uses IMS when you use the Create new project wizard.
You must then add the source files for your applications to the newly created project. These files are the program source files, DBD files (.dbd), MFS files (.mfs) and PSB files (.psb) that your applications use.
For information about creating an IMS project and adding files to it, see the chapter IMS Applications in your Getting Started manual.
You create and edit the source code for the application programs in your project in the same way as any other Mainframe Express project. See the chapter Editing Programs for more information.
You compile the program source code for an IMS project when you build an IMS project.
See the chapter IMS Applications in your Getting Started for information on building an IMS project.
You create the DBD, PSB and MFS gens when you compile the .dbd, .psb and .mfs source files.You can compile these files as a group when you build your project or individually.
You can find information on compiling individual .dbd, .psb and .mfs files in the DBD, PSB and MFS topics of the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then choose one of Working with DBD Files, Working with MFS Files or Working with PSB Files.
To view the gen files that have been created:
You see the corresponding gen members listed on the right-hand pane.
IMSGEN directives consist of DBDGEN, PSBGEN and MFSGEN directives. The specification of these directives is not required and if you do not set these directives the default directive settings apply.
For information on how to set these directives, see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then one of Working with DBD Files, Working with MFS Files and Working with PSB Files, then Project Management, then one of How to specify DBDGEN build settings, How to specify MFSGEN build settings and How to specify PSBGEN build settings. In addition, any valid DBDGEN, PSBGEN and MFSGEN directive value can be specified as an additional directive. See Enter additional DBD directives, Enter additional MFS directives and Enter additional PSB directives in the IMS Option online help.
The table below lists the valid DBDGEN, PSBGEN and MFSGEN directives. For further information see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click Reference, IMS Option, then one of DBDGEN Directives, MFSGEN Directives and PSBGEN Directives.
|DBDGEN Directives||PSBGEN Directives||MFSGEN Directives|
Usually, you need to define a transaction for any program you want to run. However, you can run a batch program (DLI or BMP programs) directly from the command line or an application region without a predefined transaction. For further information see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Managing and Running IMS Applications, How to run your programs.
For information on how to define a transaction see the IMS Option online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Defining Resources, Defining Transactions, How to add a transaction code definition.
When you define a transaction you must choose a Program type from the list available on the Transaction Properties dialog box. BMP and DLI are batch programs; MPP, NRMP and QBMP are online programs. Whether or not the remaining fields on this dialog box require a value depends on the program type you select. See the example table below:
|Process limit count||99||99||6|
|Maximum seg no||9||999||0|
Conversational MPP and NRMP programs must have a Scratch Pad Area (SPA) greater than zero.
For information on these program types, see the following topics in the online help index: BMP programs, DLI programs, MPP or NRMP programs and QBMP programs.
For information on debugging IMS programs see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Managing and Running IMS Applications, How to debug a program.
You need to define those printers that are sent messages by the applications you intend to run. For more information see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Defining Resources, Defining Printers, How to add a printer definition.
DB Catalog definitions override the DB Catalog defaults which you can set on the DB Catalog defaults page of the IMS System Properties dialog box.
For information on how to view the DB Catalog default settings or add a DB Catalog definition see the IMS Option online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Defining Resources, Defining a Database Catalog.
You can specify IMS Option databases as:
For information on these database types see the chapters Advanced Customization and IMS Fileshare Databases in your IMS Option Technical Guide.
For information on how to set the path to these databases see the online help: click Help Topics on the Mainframe Express Help menu, then on the Contents tab click IMS Option, then Defining Resources, Defining Databases.
You can use the IMSDBU utility to perform a number of database management operations; for example, loading a database.
To access IMSDBU, click IMS > Database Utility on the Tools menu. You see the IMSDBU interactive screen.
Below is an example of how to load a database using the IMSDBU utility. Loading initializes a database and then loads information from an input data file. The input data can be a .dbu file that has been downloaded from the mainframe on to your PC. Before you load a database you need to add the database definition file (.dbd) that is associated with this input data file to the project and then compile this .dbd file.
To load a database:
Press F2 to obtain a database listing. Type S (for select) next to the database you want to load and press Enter. You return to the IMSDBU main screen. Press Enter to continue.
A message indicates when the load has finished.
Loading produces a .dat file in the project's data folder.
This section describes two methods for editing databases:
Mainframe Express also provides a graphical interface for editing IMS databases. For more information, see the chapter Editing IMS Databases that describes the IMS Database Editor.
You can use the IMS Option's DBUTIL utility to retrieve, change, insert or delete segments interactively. Combined with its DBUTIL2 companion program and the IDE, you can make changes to database data with relative ease. For information on accessing and using the DBUTIL utility, see the chapter DBUTIL - Interactive DB Calls in your IMS Option Technical Guide.
You can use the Mainframe Express IDE's 'Skip to Cursor' and 'Examine' operations to create or update data. You can use:
to dynamically create segments during a debugging session. This technique provides a simple way to add segments to a database.
For example, imagine that you are debugging a program and receive a GE status code (not found) when trying to retrieve a root segment. You can insert the root segment dynamically without exiting the Mainframe Express IDE. The following steps are an example of using this technique with the IDE:
CALLverb. Select Skip to Cursor on the Debug menu to reset the Cursor position.
You see the Examine List dialog box which shows the data item and its current value.
You return to the Examine List dialog box.
If you have done this correctly, the GHU results in a 'blank' status code.
For information on debugging in the Mainframe Express IDE, see the chapter Debugging COBOL in your Getting Started.
See the chapter IMS Problem Determination in your IMS Option Technical Guide.
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|The IMS Option Interface||Editing IMS Databases|