When we use JOIN on one (self join) or more table inside a cursor declaration then a read-only cursor will be created. We cannot update the read-only cursor.If we want to update any of the tables used in the JOIN then we have to declare a separate cursor for all ... Read More

Whenever we issue a COMMIT statement, all the open cursors will get closed. This is a very common case when we have to frequently use the commit statement after a UPDATE while working with a cursor. In this case we can use the “WITH HOLD” clause during the cursor declaration.The ... Read More

The “WHERE CURRENT OF” clause will place the exclusive lock on the row once the UPDATE statement is executed. The “WHERE CURRENT OF” clause will point to the most recently fetched row of the cursor.We can update the rows in cursor using “WHERE CURRENT OF” in the following way.CURSOR definition.EXEC ... Read More

The “FOR UPDATE OF” clause is given in the cursor declaration and it is used when we want to update the table. All the columns which need to be updated should be given in the cursor declaration.The “FOR UPDATE OF” clause will place the exclusive lock on all the qualifying ... Read More

The cursor can be used to fetch multiple rows from a DB2 table. However, we have to fetch this cursor in a loop so that values corresponding to a single row are assigned to host variables at a time. Based on this logic we have to process our loop till ... Read More

The CURSOR is used when we have to fetch multiple rows from a table. There are 4 steps involved in order to use a cursor in a COBOL-DB2 program.DECLARE cursor− In this step we will define the layout of the cursor. We will give the query we want to use. ... Read More

The standalone SELECT statement is generally used when we use a primary or an alternate key in the WHERE clause. Therefore, In this case we are certain that the standalone select statement will return only one row since the primary key cannot have a duplicate value (multiple rows).If we want ... Read More

A NULL indicator is a 2 bytes field which serves the multiple purpose. This indicator takes the value as -1 when any DB2 column has NULL value and it takes the value as 0 when DB2 column has a non NULL value.Although the main purpose of the NULL indicator is ... Read More

When we define the DB2 table, we can declare any column as “NOT NULL” which means that in any case this column cannot store NULL value.Now if we try to store a NULL value in this column in our COBOL-DB2 program using -1 value in the NULL indicator then our ... Read More

We will make use of NULL indicator in order to store a NULL value in any column of a DB2 table. Firstly, we should move a value -1 in the NULL indicator in our COBOL-DB2 program. After that we execute UPDATE or INSERT query to store the NULL value.For example, ... Read More