Powerbuilder Pipeline

Another feature in Powerbuilder programming is Pipeline.
According to manual help of Powerbuilder, a Pipeline system object is used to manage a data pipeline during execution.

You use a Pipeline object by defining a standard class user object inherited from the built-in Pipeline object in the User Object painter. You can then access the Pipeline events by writing scripts that contain code for the events.

Now I will show you how to execute pipeline by writing the script.

The scenario of this case is you want to pipeline a table from one database to another database. So, first you need at least 2 transaction objects, which mean we must declare first in the top of the script. Since we have a default database connection SQLCA, we only have declare another new transaction object called SQLCAtarget, which represent for the target database connection. Remember, in this case, SQLCA will be the source of database connection

transaction SQLCAtarget // declare this variable as INSTANT variable

SQLCA.DBMS = 'your source dbms name'
SQLCA.Database = 'your source database name'
SQLCA.LogId = 'your source database login id'
SQLCA.LogPass = 'your source database password'
SQLCA.ServerName = 'your source database server'
CONNECT USING SQLCA;

SQLCAtarget = CREATE transaction
SQLCAtarget.DBMS = 'your target dbms name'
SQLCAtarget.Database = 'your target database login id'
SQLCAtarget.LogPass = 'your target database password'
SQLCAtarget.ServerName = 'your target database server'
SQLCAtarget.LogId = 'your target database login id'
CONNECT USING SQLCAtarget;

Next step, you need to build pipeline object by clicking Pipeline painter in main toolbar. Remember, use MAIN TOOLBAR, if you want to pipeline the data to ANOTHER DATABASE.
Setup your source database and the target database profile, chooce the table(s), column(s) and criteria(s), then save as pl_mypipeline.

Choose source and target of Pipeline

Set the table, column and criteria of your pipeline

save your pipeline

Create a window, then put 1 datawindow object and 1 button object. You don't need to put dataobject for the datawindow, just keep it blank. And put the script below at clicked event in button object.

integer iReturn
pipeline myPipeline
myPipeline = CREATE pipeline

myPipeline.DataObject = "pl_mypipeline"
iReturn = myPipeline.Start(SQLCA, SQLCAtarget, dw_1)

// always disconnect your database connection
DISCONNECT USING SQLCA;
DISCONNECT USING SQLCAtarget;

iReturn should be has 0 (zero) value if the pipeline run smoothly.

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How to connect to 2 databases in Powerbuilder

How to connect to more than 1 database in Powerbuilder

Some times, you need to connect to more than 1 database in your application. In Powerbuilder, there's 1 object for database connection that you can create programmatically. The object call: TRANSACTION.

In this example, I will explain how to connect to 2 databases, which mean 1 is with default database connection object (named SQLCA), and the other is the object that we create mannualy.

I'm using Microsoft SQL Server 2000 as a database engine.

First of all, we need to create a transaction object. It's depending on what the purpose of the transaction. You can declare with Instance, Global or even Local variable for this object.

Let's say we create Instant Variable, called: SQLCAID

transaction SQLCAID;

On Open Event, we must create first the transaction object, then setup the properties of the object.

Note: You can try first on the Database painter, to get the right property values, and to make sure that you can connect to the database. Then copy and paste the script.

SQLCAID = CREATE transaction;
SQLCAID.DBMS = "MSS Microsoft SQL Server"
SQLCAID.Database = "database1"
SQLCAID.LogPass = "password"
SQLCAID.ServerName = "localhost"
SQLCAID.LogId = "sa"
SQLCAID.AutoCommit = False
SQLCAID.DBParm = ""

// Try to connect the database
// REMEMBER, you must add USING SQLCAID statement at the end of your SQL Statement, every times you want to execute your database that related with SQLCAID transaction

CONNECT USING SQLCAID;

// Trap the error if the object can't connect to database

IF SQLCAID.SQLCode <> 0 THEN
    MessageBox("Connection Error to "+SQLCAID.Database, &
        "Unable to connect to database. Make sure you type the correct password." + &
        "~r~nTry Again. If the problem persists, contact IT Officer" + &
        "~r~nSQLDBCode = " + String(SQLCAID.SQLDBCode) + &
        "~r~nSQLErrText = " + SQLCAID.SQLErrText)
   HALT
END IF


At the other side, you still must declare the DEFAULT SQLCA transaction object.

SQLCA.DBMS = "MSS Microsoft SQL Server"
SQLCA.Database = "databasedefault"
SQLCA.LogPass = "password"
SQLCA.ServerName = "localhost"
SQLCA.LogId = "sa"
SQLCA.AutoCommit = False
SQLCA.DBParm = ""

// Just for make sure that you connect with SQLCA transaction

CONNECT USING SQLCA;

// Trap the error if the object can't connect to database
IF SQLCA.SQLCode <> 0 THEN
    MessageBox("Connection Error to "+SQLCA.Database, &
        "Unable to connect to database. Make sure you type the correct password." + &
        "~r~nTry Again. If the problem persists, contact IT Officer" + &
        "~r~nSQLDBCode = " + String(SQLCA.SQLDBCode) + &
        "~r~nSQLErrText = " + SQLCA.SQLErrText)
   HALT
END IF

Now you already connected with 2 databases.

Remember, always put USING SQLCA or USING SQLCAID statement at the end of your SQL Statement to make sure that the SQL Statement will execute into the database that you purpose

Example:

string sProductID, sProductName

// will retrieve the product_id and product_name column from SQLCAID transaction
SELECT product_id, product_name INTO :sProductID, :sProductName FROM product_master USING SQLCAID;

// will retrieve the product_id and product_name column from SQLCA (Default) transaction
SELECT product_id, product_name INTO :sProductID, :sProductName FROM product_master USING SQLCA;

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