Tutorial: Application Migration - Converting Labeled Duration Calculations

This tutorial takes you through the process of migrating a DB2 application to a SQL Server application, using HCOSS to convert labeled duration calculations and managing date formats.

SQL Server does not support labeled duration calculations directly. HCOSS handles the conversion to T-SQL to implement the DB2 syntax of an EXEC SQL statement using labeled durations.

This tutorial also demonstrates binding the application using a post-build event in Visual Studio.

Requirements

Before attempting this tutorial, you must first complete the following tutorials to ensure you have an established SQL Server database named HCO_Test containing the required PROD and TEST schemas and a connection to the HCO_Test database:
  • Tutorial: Create a SQL Server Database
  • Tutorial: Create a Database Connection
  • Tutorial: DB2 Database Migration or Tutorial: Setup for Application Migration Tutorials

Visual Studio Solution

The Visual Studio solution we provide for this tutorial contains two HCOSS projects. The LBLDURATION project is a native COBOL project. The MLBLDURATION project is a managed COBOL project. However, the COBOL code is the same in both projects.

Phase 1: Start Enterprise Developer and HCO for SQL Server Tools

If Enterprise Developer and HCOSS for SQL Server tools are already running, skip this phase.

  1. Start Enterprise Developer as an administrator. This procedure varies depending on your Windows version. If you need instructions, see To start Enterprise Developer as an administrator.
  2. In Visual Studio, click View > Micro Focus SQL Tools > HCO for SQL Server Tools.

Phase 2: Analyze, Build, and Bind the Native Application

Analyze the Native Application
  1. In Visual Studio, open the solution named LBLDURATION, which is located in the %PUBLIC%\Documents\Micro Focus\Enterprise Developer\Samples\Mainframe\SQL\hcoss\LBLDURATION directory.
  2. From the Solution Explorer, open the LBLDURATION.cbl file to view its contents. Pay particular attention to the following EXEC SQL statement:
               EXEC SQL 
                   DECLARE CSR69 CURSOR FOR SELECT 
                    A.PROJNO
                   ,A.PROJNAME
                   ,A.PRSTDATE
                   ,A.PRENDATE
                   ,(((DAYS(A.PRENDATE) - DAYS(A.PRSTDATE) ) / 7) + 1) * 40 
                   AS MANHOURS
                   FROM PROJ A
                   ORDER BY A.PROJNAME
               END-EXEC
    This contains your labeled duration calculation:
    ,(((DAYS(A.PRENDATE) - DAYS(A.PRSTDATE) ) / 7) + 1) * 40
    In this case, you are using the DAYS labeled duration in a calculation where you:
    • Start with the number of days between the start and end date for projects
    • Divide that number by 7 to get the number of weeks
    • Add 1 to account for truncation of a partial week
    • Multiply that result by 40 to get the number of hours needed to complete the project
  3. Close the code editor.
  4. Open the project properties for the LBLDURATION project.
  5. Notice that the Output type on the Application tab is Console Application.
  6. Switch to the COBOL tab, and set the following:
    Configuration Debug
    Platform target x86 (default)
  7. Switch to the SQL tab. Several OpenESQL compiler directives have been set for you. The following table offers a brief description of each:
    SQL(DBMAN=ODBC) Uses an ODBC connection
    SQL(TARGETDB=MSSQLSERVER) Target database is SQL Server
    SQL(DB=HCODemo) SQL Server connection name is HCODemo
    SQL(DIALECT=MAINFRAME) HCOSS database syntax conversion is enabled
    SQL(DBRMLIB) EXEC-SQL commands are extracted and placed in database request module (DBRM)
    SQL(DATE=USA) Date output is in USA format
    SQL(INIT) Initiates the database connection
    SQL(QUALIFIER=TEST) Schema qualifier is TEST
    SQL(NOCHECK) No SQL compile-time checking performed
    SQL(BEHAVIOR=OPTIMIZED) Optimizes migration process
Define a Post-Build Event
  1. In the Properties window, click the COBOL tab; then click Build Events.
  2. In the Post build event command line field, type the following command:
    DSN SYSTEM(HCODemo) @"$(ProjectDir)LBLDURATION.hcodsn"

    This command calls the DSN Bind utility, specifies the SQL database connection to use, and states the location and name of a bind script file. Visual Studio executes this event immediately after building the application, automatically binding the application at that time.

  3. Click OK to close the Build Events dialog box.
View the Contents of the Bind Script File
  • From the Solution Explorer, open and review the content of LBLDURATION.hcodsn. This bind script file contains one BIND PLAN command that binds the LBLDURATION member into a plan named LBLDURATION.
Build and Bind the Applcation
  1. From the Solution Explorer, rebuild the LBLDURATION project, thereby generating a DBRM for the application and automatically binding it to the DBRM using the post-build event.
  2. Verify that the project built successfully.
Verify the Results
  1. Using Microsoft SQL Server Management Studio, connect to your SQL Server instance.
  2. On the Object Explorer, expand Databases > HCO_Test > Programmability > Stored Procedures to see the stored procedures HCOSS created when you executed your packages and plan.
  3. Open the stored procedure named PLN:LBLDURATION.LBLDURATIONconsistency-token$0, where consistency-token is the value of the generated consistency token.

    In this, you see the SQL from your application code. You also see that HCOSS has converted the original DB2 DAYS expression into T-SQL syntax that recreates the same functionality in SQL Server. This is due to having set the SQL(DIALECT=MAINFRAME) directive when you compiled.

Phase 3: Run the Native Application

  1. From the Solution Explorer, open the LBLDURATION.cbl source file.
  2. Set a break point on the GO BACK line.
  3. Press F5 to start debugging.
  4. Use the tools available from the Debug toolbar or menu to continue to your breakpoint.

You see from the output that your results show the hours required to complete each project. All output dates are in USA format.

Phase 4: Analyze, Build, Bind, and Run the Managed Application

Analyze the Managed Application
  1. From the Solution Explorer, switch the starting project: Right-click the MLBLDURATION project and select Set as StartUp Project.
  2. Open the project properties for the MLBLDURATION project.
  3. Click the SQL tab.

    Notice the directive settings for the OpenESQL ESQL Preprocessor include SQL(DBMAN=ADO). This means that we're using the ADO.NET database connection rather than the ODBC database connection.

    Also notice the SQL(DATE=EUR) directive, which specifies the European output format.

Define a Post-Build Event
  1. From the Properties window add a post-build event to execute the following command (same command you used for the native project):
    DSN SYSTEM(HCODemo) @"$(ProjectDir)LBLDURATION.hcodsn"
  2. Close the Properties window.
Build and Bind the Managed Application
  • From the Solution Explorer, right-click the MLBLDURATION project and select Rebuild.
Run the Managed Application
  1. From the Solution Explorer in Visual Studio, open the LBLDURATION.cbl source file.
  2. Set a break point on the GO BACK line.
  3. Run the application.

This completes the tutorial.