Sunday, February 23, 2014

SSIS Interview: Data Conversion and Derived Column

The Data Conversion Transform performs a similar function to the CONVERT or CAST
Functions In TSQL. The transform is configured in the Data Conversion Transformation Editor,
where you would check each column that you wished to convert and then assign what you
wish to convert it to under the Data Type column.
The Output Alias is the column name you want to assign to the column after it is transformed.
If you don ’ t assign it a new name, it will show as Data Conversion: ColumnName later in the
Data Flow.
The Derived Column Transform creates a new column that is derived from the output
Another column. It is one of the most important transforms in your Data Flow arsenal. You may
wish to use this transformation, for example, to multiply the quantity of orders by the cost of
the order to derive the total cost of the order. You can also use it to find out
the current date or to fill in the blanks in the data by using the ISNULL function. This is one of
the top five transforms that you ’ ll find yourself using to alleviate the need for TSQL scripting in
the package. To configure this transform, drag the column or variable into the Expression
column .Then add any functions to it. A list of functions can be found in the top - right corner of
the Derive Column Transformation Editor. You must then specify, in the Derived Column drop
down box, if you want the output to replace an existing column in the Data Flow or to create a
new column.
 
 
Label: SSIS Interview Questions, SSIS Interview Question and Answer

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