What is the use of a cursor in SQL Server?

后端 未结 6 611
滥情空心
滥情空心 2020-12-13 18:47

I want to use a database cursor; first I need to understand what its use and syntax are, and in which scenario we can use this in stored procedures? Are there different synt

6条回答
  •  情书的邮戳
    2020-12-13 19:09

    In SQL server, a cursor is used when you need Instead of the T-SQL commands that operate on all the rows in the result set one at a time, we use a cursor when we need to update records in a database table in a singleton fashion, in other words row by row.to fetch one row at a time or row by row.

    Working with cursors consists of several steps:

    Declare - Declare is used to define a new cursor. Open - A Cursor is opened and populated by executing the SQL statement defined by the cursor. Fetch - When the cursor is opened, rows can be retrieved from the cursor one by one. Close - After data operations, we should close the cursor explicitly. Deallocate - Finally, we need to delete the cursor definition and release all the system resources associated with the cursor. Syntax

    DECLARE cursor_name CURSOR [ LOCAL | GLOBAL ] [ FORWARD_ONLY | SCROLL ] [ STATIC | KEYSET | DYNAMIC | FAST_FORWARD ] [ READ_ONLY | SCROLL_LOCKS | OPTIMISTIC ] [ TYPE_WARNING] FOR select_statement [FOR UPDATE [ OF column_name [ ,...n ] ] ] [;]

提交回复
热议问题