T-SQL Tutorial

Cursor to insert records

A cursor in SQL Server is a database object that is used to iterate over a set of records one by one. Cursors are typically used when a process requires row-by-row processing of a result set or when a process needs to make updates to individual rows in a result set.

To use a cursor in SQL Server to insert records, you first need to define a cursor that selects the records to be inserted.


Here is an example of how to define a cursor:

SELECT Column1, Column2, Column3
FROM MyTable_1
WHERE Column4 = 'SomeValue'

In this example, the cursor is selecting records from the "MyTable_1" table where "Column4" equals 'SomeValue'. You can modify this query to select the records you want to insert. Once you have defined the cursor, you can use a loop to iterate over each record and perform the insert operation. Here is an example of how to use a cursor to insert records:

DECLARE @Column1 DataType1
DECLARE @Column2 DataType2
DECLARE @Column3 DataType3
OPEN myCursor
FETCH NEXT FROM myCursor INTO @Column1, @Column2, @Column3
INSERT INTO MyTable_2 (Column1, Column2, Column3)
VALUES (@Column1, @Column2, @Column3)
FETCH NEXT FROM myCursor INTO @Column1, @Column2, @Column3
CLOSE myCursor

In this example, the cursor is opened, and the first record is fetched into variables @Column1, @Column2, and @Column3. The loop then continues to insert each record into the "MyTable_2" table until there are no more records to fetch.

Once the loop is complete, the cursor is closed and deallocated.

It is important to note that cursors can be slow and can cause performance issues if used improperly. Therefore, it is recommended to use cursors only when necessary and to try to use set-based operations instead whenever possible.