What is the syntax of cursor in SQL?
What is the syntax of cursor in SQL?
To use cursors in SQL procedures, you need to do the following: Declare a cursor that defines a result set. Open the cursor to establish the result set. Fetch the data into local variables as needed from the cursor, one row at a time.
What Is syntax for cursor?
Syntax: DECLARE CURSOR IS ; BEGIN FOR I IN LOOP . . END LOOP; END; In the above syntax, the declaration part contains the declaration of the cursor.
How do you create a cursor in SQL Server?
Cursor in SQL Server
- DECLARE statements – Declare variables used in the code block.
- SET\SELECT statements – Initialize the variables to a specific value.
- DECLARE CURSOR statement – Populate the cursor with values that will be evaluated.
- OPEN statement – Open the cursor to begin data processing.
What is cursor and its syntax?
A cursor holds the rows (one or more) returned by a SQL statement. The set of rows the cursor holds is referred to as the active set. You can name a cursor so that it could be referred to in a program to fetch and process the rows returned by the SQL statement, one at a time. There are two types of cursors −
Why use triggers in SQL?
Because a trigger resides in the database and anyone who has the required privilege can use it, a trigger lets you write a set of SQL statements that multiple applications can use. It lets you avoid redundant code when multiple programs need to perform the same database operation.
How do I make my cursor explicit?
There are four steps in using an Explicit Cursor.
- DECLARE the cursor in the declaration section.
- OPEN the cursor in the Execution Section.
- FETCH the data from cursor into PL/SQL variables or records in the Execution Section.
- CLOSE the cursor in the Execution Section before you end the PL/SQL Block.
What is cursor short answer?
1) A cursor is the position indicator on a computer display screen where a user can enter text. In an operating system with a graphical user interface (GUI), the cursor is also a visible and moving pointer that the user controls with a mouse, touch pad, or similar input device.
What is declare cursor?
DECLARE CURSOR defines the attributes of a Transact-SQL server cursor, such as its scrolling behavior and the query used to build the result set on which the cursor operates. The OPEN statement populates the result set, and FETCH returns a row from the result set.
Why is trigger used?
A trigger is designed to check or change data based on a data modification or definition statement; it should’t return data to the user. The Transact-SQL statements in a trigger frequently include control-of-flow language. SELECT * FROM deleted; For more information, see Use the inserted and deleted Tables.
What is the use of cursor in SQL Server?
Cursors 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.
How do you create a cursor in SQL?
Follow these steps to create a cursor: Associate a cursor with a resultSet of a T-SQL statement, and define the characteristics of the cursor, such as how the rows are going to be retrieved, and so forth. Execute the T-SQL statement to populate the cursor. Retrieve the rows in the cursor.
How do I query XML in SQL?
To use XQuery to query XML data from a SQL Server 2000 database, follow these steps: Include well-formed XML tags in the text data that you want to store in a SQL Server 2000 database. Store the data in a column that has a text data type such as nvarchar or ntext. Open SQL Server Management Studio, and then create a new query.
What is Oracle SQL cursor?
The Cursor is a handle (name or a pointer) for the memory associated with a specific statement. A cursor is basically an Area alocated by Oracle for executing the Sql Statements. Oracle Uses an Implicit Cursor statement for a single row query and Explicit Cursor for a multi row query.