How Can I Execute a Stored Procedure for Each Row Returned by a T-SQL Query?

Executing Stored Procedures for Each Row of Query Results in T-SQL

To iterate through the results of a query and execute a stored procedure for each row, a CURSOR can be utilized in T-SQL. A CURSOR allows you to retrieve one row at a time from a result set, making it well-suited for this scenario.

To achieve this looping functionality, the following steps outline the solution in T-SQL:

1. Declare necessary variables:
   a. Declare an integer variable @id to store the ID value from each row.
   b. Declare a second variable @name, for example, to store an additional column value from the table.
   c. Declare a CURSOR variable @getid to hold the cursor that will step through the rows.
2. Create the CURSOR:
   Use the SET statement to assign a value to @getid, where the value is a SQL statement that selects the desired columns from the table. In this example, we select both id and name.
3. Open the CURSOR:
   Use the OPEN statement to open the CURSOR, making it available for retrieval operations.
4. Fetch the first row:
   Use the FETCH NEXT statement to retrieve the first row of the result set into the declared variables (@id and @name).
5. Loop through the rows:
   Use a WHILE loop to iterate through the remaining rows as long as the @@FETCH_STATUS is 0, indicating there are more rows to process.
6. Execute the stored procedure:
   Inside the loop, execute the stored procedure using the EXEC statement, passing the appropriate parameters from the current row. In this example, we pass @id, @otherVarName, and @varForName.
7. Fetch the next row:
   After executing the stored procedure, use FETCH NEXT again to retrieve the next row into the declared variables.
8. Close and deallocate the CURSOR:
   After processing all rows, use the CLOSE and DEALLOCATE statements to release the CURSOR resources.

By following these steps, you can effectively loop over the results of a query in T-SQL and execute a stored procedure for each row, enabling you to perform custom operations based on the retrieved data.

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