DataStage and Date Functions

In DataStage, date functions are essential for manipulating dates and times in a variety of ways. This article provides an overview of the most commonly used date functions in DataStage.

1. Current_Date()

The Current_Date() function returns the current system date. Here's a simple example:

StreamStage currentDateStage = new StreamStage("Current Date Stage");
TransformModule currentDateTrans = currentDateStage.newTransformModule("Current Date Transformer");
currentDateTrans.setExpression("Output(Current_Date())");
currentDateStage.setInput(inputStream)
                .addTransform(currentDateTrans)
                .setOutput(outputStream);

2. Add_Months()

The Add_Months(date, number) function adds a specified number of months to a given date. For example:

StreamStage addMonthsStage = new StreamStage("Add Months Stage");
TransformModule addMonthsTrans = addMonthsStage.newTransformModule("Add Months Transformer");
addMonthsTrans.setExpression("Output(Add_Months(Input(), 3))");
addMonthsStage.setInput(inputStream)
              .addTransform(addMonthsTrans)
              .setOutput(outputStream);

3. Add_Years()

The Add_Years(date, number) function adds a specified number of years to a given date. For example:

StreamStage addYearsStage = new StreamStage("Add Years Stage");
TransformModule addYearsTrans = addYearsStage.newTransformModule("Add Years Transformer");
addYearsTrans.setExpression("Output(Add_Years(Input(), 5))");
addYearsStage.setInput(inputStream)
             .addTransform(addYearsTrans)
             .setOutput(outputStream);

4. Extract Functions

DataStage provides various extract functions to get specific parts of a date. For example, Year(date), Month(date), Day(date), Hour(date), Minute(date), and Second(date). Here's an example using the Year() function:

StreamStage yearStage = new StreamStage("Year Stage");
TransformModule yearTrans = yearStage.newTransformModule("Year Transformer");
yearTrans.setExpression("Output(Year(Input()))");
yearStage.setInput(inputStream)
         .addTransform(yearTrans)
         .setOutput(outputStream);

5. Format_Date()

The Format_Date(date, format) function formats a date according to the specified pattern. For example:

StreamStage formatDateStage = new StreamStage("Format Date Stage");
TransformModule formatDateTrans = formatDateStage.newTransformModule("Format Date Transformer");
formatDateTrans.setExpression("Output(Format_Date(Input(), 'YYYY-MM-DD'))");
formatDateStage.setInput(inputStream)
               .addTransform(formatDateTrans)
               .setOutput(outputStream);