SSIS:OPTION TO CONTROL HOW DATA IS WRITTEN TO A DESTINATION

https://learn.microsoft.com/en-us/sql/integration-services/data-flow/flat-file-destination?view=sql-server-ver16

In SSIS (SQL Server Integration Services), the option to control how data is written to a destination is typically managed through the use of the "Data Flow Destination" component settings, depending on the specific destination type. Here's how you can control the behavior:

1. OLE DB Destination:
   

   • When using an OLE DB Destination, you have the option to choose the "Data access mode" in the destination editor.

   • The available options are:

     • Table or view: This will either overwrite or append data to the destination table, depending on whether you choose "Drop and re-create table" or "Append rows to the destination table" in the "Table or view" dropdown menu.

     • Table or view - fast load: Similar to the above, but optimized for bulk loading.

1. Flat File Destination:
   

   • In a Flat File Destination, you have the option to specify whether you want to create a new file or overwrite an existing one. This is configured in the connection manager settings.

OVERWRITE

In above highlighted part of image if the option is check then it will erase existing records and write new records

APPEND

if the option is left blank then in case it will append records in existing excel ,so old and new records will be present

1. Excel Destination:
   

   • When writing to an Excel file, you can choose to either create a new sheet or overwrite an existing one in the Excel destination editor.

1. ADO.NET Destination:
   

   • The behavior in an ADO.NET Destination is somewhat similar to an OLE DB Destination. You can choose to either create a new table or append rows to an existing table, depending on your settings.

1. SQL Server Destination:
   

   • In a SQL Server Destination, you can specify whether you want to create a new table or append rows to an existing one in the destination editor.

1. Merge Join and Lookup Transformations:
   

   • While not technically destinations, these transformations can also influence how data is matched and merged in the data flow, which can be crucial for scenarios involving updates or inserts.

Remember to carefully configure your destination components based on your specific requirements, and be cautious when choosing options that may result in data loss or unwanted changes in your destination. Always make sure to have a backup or a way to revert to previous data if needed.