The OPEN CURSOR statement initializes and activates a previously declared cursor. Once a cursor is declared with a SELECT statement, OPEN CURSOR executes the SELECT query, preparing the cursor to retrieve rows from the result set.

The OPEN CURSOR statement is used to activate a cursor so that it can start fetching rows. When we open a cursor:

• DB2 processes the SQL SELECT statement defined in the DECLARE CURSOR statement.
• The cursor is positioned at the beginning of the result set, ready to retrieve rows with the FETCH command.
• This allows COBOL programs to work with multiple rows from the result set one at a time without loading all rows simultaneously.

The cursor cannot fetch rows without an OPEN CURSOR because the result set has not yet been initialized.

Syntax -

EXEC SQL
	OPEN cursor-name
END-EXEC.

• cursor_name: The name of the cursor that was previously declared with a SELECT statement. This name is used consistently throughout the cursor’s lifecycle in SQL commands such as OPEN, FETCH, and CLOSE.

Example -

Input-

Scenario1 - Open cusor.

Code -

   EXEC SQL 
	OPEN C1
   END-EXEC.

Scenario2 - Open cursor using host variables HV1, HV2 to receive two column values.

Code -

   EXEC SQL 
	OPEN C2 USING :HV1, :HV2
   END-EXEC.

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