Can I loop through a table in SQL?

Can I loop through a table in SQL?

Pros and Cons of Using a While Loop to Iterate Through Table Rows in SQL Server. While loops are faster than cursors. While loops use less locks than cursors. Less usage of Tempdb: While loops don’t create a copy of data in tempdb as a cursor does.

How do you optimize a WHILE loop in SQL?

Getting Started

1. Avoid the use of the WHILE LOOP.
2. Use UNION ALL instead of UNION whenever is possible.
3. Avoid using the joins of multiple tables in the where and join in the from clause.

Which is better cursor or WHILE loop?

Always confusing thing is which one is better; SQL While loop or cursor? While SQL While loop is quicker than a cursor, reason found that cursor is defined by DECLARE CURSOR. Every emphasis of the loop will be executed inside system memory and consuming required server assets.

How do you write a while loop in SQL?

SQL While loop syntax The while loop in SQL begins with the WHILE keyword followed by the condition which returns a Boolean value i.e. True or False. The body of the while loop keeps executing unless the condition returns false. The body of a while loop in SQL starts with a BEGIN block and ends with an END block.

How to use a while loop in SQL Server?

SQL Server Cursor Example Converted to a While Loop. In order to replace this cursor with a WHILE LOOP, we need to create a temporary table to implement a tally table. For all of you who don’t know what a tally table is, we can define it as a table that contains a pair of columns consisting of a key and its value.

Which is the most efficient way to loop through a table?

And the window spool doesn’t release the first “Jo” row until it has read the next row with a different turn(for thomas – turn = 3) So the window spool and stream aggregate both cause an additional row to be read and there are four of these in the plan – hence 4 additional rows.

Which is better a cursor or a loop in SQL Server?

Pros and Cons of Using a While Loop to Iterate Through Table Rows in SQL Server. There are also benefits to use a WHILE loop compared to a cursor. While loops are faster than cursors. While loops use less locks than cursors. Less usage of Tempdb: While loops don’t create a copy of data in tempdb as a cursor does.

How to loop through table rows without cursor?

The idea is to loop trough the table rows ordered by the CursorTestID column and update the RunningTotal column with the sum of the CursorTestID column value and the value of the RunningTotal column of the previous row. But before starting, first we need to generate some test rows with the next script.