What is the cursor life cycle?

What is the cursor life cycle?

SQL Cursor Life Cycle A cursor is declared by defining the SQL statement. A cursor is opened for storing data retrieved from the result set. When a cursor is opened, rows can be fetched from the cursor one by one or in a block to do data manipulation. The cursor should be closed explicitly after data manipulation.

How does cursor work in DB2?

DB2 uses a cursor to make the rows, from the results table, available to the application program. A cursor identifies the current row of the results table. When you use a cursor, the program can retrieve each row sequentially from the results table until end-of-data (i.e the not found condition SQLCODE=100).

How many types of cursors are there in DB2?

These two types of cursors are the type of updatable cursor.

What are cursor operations?

Cursors are used for operating on collections of records, for iterating over a database, and for saving handles to individual records, so that they can be modified after they have been read. The DB->cursor() method opens a cursor into a database.

What is the chronological order of cursor phases?

The lifecycle of a cursor typically involves five stages:

• Declare: The first step is to declare a cursor.
• Open: Next, the system is instructed to open the cursor.
• Fetch: This is the recurring step in the whole process.
• Close: After the data manipulation is done, the cursor needs to be closed.

What occurs when a cursor is opened?

When a cursor is opened, the following things happen: The values of the bind variables are examined. Based on the values of the bind variables, the active set (the query result) is determined. The active set pointer is set to the first row.

What is the difference between cursor and select statement?

Opening the cursor To open a cursor, it is required to declare it first. It is declared using the DATA statement and special data type CURSOR. All clauses of SELECT statement can be used except the INTO clause. After the OPEN CURSOR statement, the database cursor points to the first line of the result set.

What is scrollable cursor in DB2?

With scrollable cursors, you can move directly to the rows you want without having to FETCH every other row returned by the cursor. In DB2 V7, scrollable cursors require you to use declared temporary tables, another new feature of DB2 Version 7.

What is a cursor in a database?

A database cursor is an identifier associated with a group of rows. It is, in a sense, a pointer to the current row in a buffer. Statements that return more than one row of data from the database server: A SELECT statement requires a select cursor. An EXECUTE FUNCTION statement requires a function cursor.

When do you open the cursor in DB2?

After the DECLARE CURSOR statement executes, you process the result table of a cursor as follows: Open the cursor before you retrieve any rows. To tell Db2 that you are ready to process the first row of the result table, have your program issue the OPEN statement.

How to use Db2 cursor in COBOL programs?

DB2 Cursor use in COBOL Programs 1 DECLARE DB2 cursor. Defines the cursor, gives it a name unique to the program in which it is embedded, and assigns an SQL statement to the cursor name. 2 OPEN DB2 cursor. Readies the cursor for row retrieval. 3 FETCH DB2 cursor. 4 CLOSE DB2 cursor. 5 UPDATE DB2 cursor. 6 DELETE DB2 cursor.

What does the Declare statement do in DB2?

DECLARE DB2 cursor statement. Defines the cursor, gives it a name unique to the program in which it is embedded, and assigns an SQL statement to the cursor name. The DECLARE statement does not execute the SQL statement; it merely defines the SQL statement.

What is the product lifecycle for IBM DB2 tools?

The IBM DB2 Tools Product Lifecycle matrix displays the marketing and support services available to you over the life of your product. You can click the dates that are listed to go directly to the product announcement letter.