Lookup - ( SSIS Data Flow )

Syntax

Lookup Transformation

Example

Consider a scenario where you have two tables, Table A and Table B. Table A has a column named "ID" and Table B also has a column named "ID". You want to join these two tables using the "ID" column. You can use the SSIS Lookup transformation to perform this join operation.

Output

Using the SSIS Lookup transformation, you can get the result of the join operation between the two tables.

Explanation

The Lookup transformation in SSIS is used to join data from two sources based on a common key. It is similar to the SQL Join operation, where two tables are joined based on a common column. The Lookup transformation can be used in the SSIS Data Flow task to perform a lookup against a reference dataset, and retrieve the matching values based on a specified key column.

The Lookup transformation has two inputs, the "Data Flow Input" and the "Reference Input". The "Data Flow Input" is the input from the source data, and the "Reference Input" is the input from the reference dataset. The Lookup transformation performs the join operation based on the specified key columns and returns the matching rows.

Use

The SSIS Lookup transformation is commonly used in several scenarios. Some of them are:

• Joining two tables based on a common column
• Finding the corresponding value of a foreign key column from a reference table
• Updating the value of a column in a destination table based on the value of a column in the source table

Important Points

• The SSIS Lookup transformation requires a sorted reference dataset to perform the lookup operation.
• The "Lookup No Match Output" option can be used to handle the rows that do not have a match in the reference dataset.
• The "Cache Mode" option can be used to choose how the reference dataset will be stored in memory during the lookup operation.

Summary

The SSIS Lookup transformation is a powerful tool for joining data from different sources based on a common key. It is commonly used in ETL projects to perform lookup operations and retrieve the matching values. Understanding the syntax and usage of the Lookup transformation can greatly improve your SSIS skills and make your data flow tasks more efficient.