What is cursor in SQL Server?

A SQL cursor is a database object that retrieves data from result sets one row at a time. The cursor in SQL can be used when the data needs to be updated row by row. A SQL cursor is a database object that is used to retrieve data from a result set one row at a time.

What is SQL cursor example?

A SQL Server cursor is a set of T-SQL logic to loop over a predetermined number of rows one at a time. The purpose for the cursor may be to update one row at a time or perform an administrative process such as SQL Server database backups in a sequential manner.

What is the use of cursor in SQL?

The major function of a cursor is to retrieve data, one row at a time, from a result set, unlike the SQL commands which operate on all the rows in the result set at one time. Cursors are used when the user needs to update records in a singleton fashion or in a row by row manner, in a database table.

What is the default cursor type in SQL Server?

static cursor
A static cursor can move forward and backward. This is the default type of cursor. It is identical to the static except that you can only scroll forward. In a dynamic cursor, additions and deletions are visible for others in the data source while the cursor is open.

What is cursor example?

Oracle creates a memory area, known as the context area, for processing an SQL statement, which contains all the information needed for processing the statement; for example, the number of rows processed, etc. A cursor is a pointer to this context area. A cursor holds the rows (one or more) returned by a SQL statement.

What is difference between trigger and cursor?

A trigger is a procedure (code segment) that is executed automatically when some specific events occur in a table/view of a database, while a cursor is a control structure used in databases to go through the database records.

What is cursor and its types?

Cursor is a Temporary Memory or Temporary Work Station. It is Allocated by Database Server at the Time of Performing DML operations on Table by User. Cursors are used to store Database Tables. There are 2 types of Cursors: Implicit Cursors, and Explicit Cursors.

Which is faster cursor or while loop?

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.

Is it good to use cursor in SQL?

Cursors could be used in some applications for serialized operations as shown in example above, but generally they should be avoided because they bring a negative impact on performance, especially when operating on a large sets of data.

What is the advantage of cursor?

Cursors can be faster than a while loop but they do have more overhead. It is we can do RowWise validation or in other way you can perform operation on each Row. It is a Data Type which is used to define multi-value variable. Cursors can be faster than a while loop but at the cost of more overhead.

Can we declare cursor inside begin?

In general, yes you can, you just nest another execution block inside your current one…

Which is an example of a cursor in SQL Server?

SQL Server cursor example. We’ll use the prodution.products table from the sample database to show you how to use a cursor: First, declare two variables to hold product name and list price, and a cursor to hold the result of a query that retrieves product name and list price from the production.products table:

Why is the cursor not able to scroll backward in SQL?

Because the cursor cannot be scrolled backward, however, changes made to rows in the database after the row was fetched are not visible through the cursor. Forward-only cursors are dynamic by default, meaning that all changes are detected as the current row is processed.

When to close the cursor in SQL Server?

Fetch the next record from cursor as you did in step 3 and then step 4 is repeated again by processing the selected data. Once all of the data has been processed, then you close cursor. As a final and important step, you need to deallocate the cursor to release all of the internal resources SQL Server is holding.

How to fetch rows from the cursor in SQL Server?

SQL Server provides the @@FETCHSTATUS function that returns the status of the last cursor FETCH statement executed against the cursor; If @@FETCHSTATUS returns 0, meaning the FETCH statement was successful. You can use the WHILE statement to fetch all rows from the cursor as shown in the following code: After that, close the cursor: