Updating rows in sql
Many a times, you come across a requirement to update a large table in SQL Server that has millions of rows (say more than 5 millions) in it.
Target(Employee ID, Employee Name) VALUES(101, 'Sara'); INSERT dbo.
If the table has too many indices, it is better to disable them during update and enable it again after update3.
Instead of updating the table in single shot, break it into groups as shown in the above example.
Assume we have the following two tables: Table Store_Information We want to remove data for all stores in the East region from Store_Information (assuming that a store is either in the East region or the West region—it cannot be in more than one region).
We use the following SQL statement to accomplish this: If we leave out the WHERE clause in a DELETE FROM command, we will delete all rows from the table. To prevent this, it is a best practice in database management to always run the corresponding SELECT statement first to make sure the rows selected are the ones we intend to remove from the table.
Search for updating rows in sql:
This can be done by replacing "DELETE" with "SELECT *".