Cursor in sql code project

A cursor is a temporary work area created in the system memory when a SQL statement is executed. A cursor contains information on a select statement and the rows of data accessed by it. This temporary work area is used to store the data retrieved from the database, and manipulate this data. Oracle associates every SELECT statement with a cursor to hold the query information in this context area. There are two types of cursors - implicit and explicit cursor.

In this post, we are going to create a cursor in databases like SQL Server, Oracle, MySQL, PostgreSQL. Here, we will be able to find basic similarities and differences between implementation and execution process while working with the same CURSOR clause in different databases. The second case where cursors may be useful is to create a “for each” type logic in T-SQL scripts. For example, if one would like to handle the deployment of individual tables to another database one could use a cursor and sp_executeSql to run a chunk of T-SQL for each table in a give list. We use a cursor when we need to update records in a database table in singleton fashion means row by row.

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. Creating a SQL Server cursor is a consistent process, so once you learn the steps you are easily able to duplicate them with various sets of logic to loop through data. The OPEN statement populates the result set, and FETCH returns a row from the result set.

If you possess programming skills, you would probably use a loop like FOR or WHILE to iterate through one item at a time, do something with the data and the job is done. Below is a function that uses this cursor. In T-SQL, a CURSOR is a similar approach, and might be preferred because it follows the same logic. But be advise take this path and trouble may follow. So this article takes a step back and provides an explanation as to what SQL Server cursors can be used for as well as a basic example that you can run for yourself to test.

Transactional versus Procedural Programming. The SELECT statement associated with the cursor. In this article I will provide a simple Cursor tutorial with Syntax example in SQL Server. Is there a way to perform a Cursor For Loop with an dynamic SQL -statement? T- SQL : A Simple Example Using a Cursor.

Disclaimer: This site is started with intent to serve the ASP. Net Community by providing forums (question-answer) site where people can help each other. The first section of code declares the cursor. The SQL engine allocates memory for the cursor and populates it with the data set you define in the SELECT statement.

LOCAL and GLOBAL keywords in the DECLARE CURSOR statement are used to specify the scope of a cursor. In SQL Server, there are two options to define the scope of a cursor. A GLOBAL cursor can be referenced in any stored procedure or batch executed by a connection.

A cursor is used to referred to a program to fetch and process the rows returned by the SQL statement, one at a time. Cursor is supported in all SQL Server versions i. This is a common approach for developers. This can be accomplished by using a cursor.

The following data will be displayed in SQL Server when you run a simple SELECT query using the dbo.