While updating records using cursor
PL/SQL also supports dynamic SQL, which enables you to execute SQL data definition, data control, and session control statements dynamically.In addition, PL/SQL conforms to the current ANSI/ISO SQL standard.statements might credit one bank account and debit another.
To save an attribute value for later use, assign it to a Boolean variable immediately.
In this scenario, the cursor result set can be limited using the traditional When we associate a SELECT statement with more than one table joined together to a cursor with a FOR UPDATE clause, we end up locking all the tables in the FROM clause of the SELECT statement, where we just need to lock a single table for our purpose.
The FOR UPDATE OF clause helps us in locking up the intended table rather all available tables.
You might use sequence numbers to give each row a unique identifier, and refer to those identifiers from other rows to set up parent-child relationships.
CREATE table1 AS SELECT object_name, object_type FROM user_objects; BEGIN INSERT INTO table1(col1, col2) VALUES('value1','value2'); UPDATE table1 SET col1 = 'another value' WHERE col2 IS NULL; DELETE FROM table1 WHERE col1 = col2; COMMIT; END; / DROP table1; CREATE table1 AS SELECT object_name, object_type FROM user_objects; DECLARE x VARCHAR2(128) := 'value1'; y NUMBER := 10; BEGIN INSERT INTO table1(col1, col2) VALUES(x, x); UPDATE table1 SET col1 = x WHERE col3 The values of the cursor attributes always refer to the most recently executed SQL statement, wherever that statement is.
Rows Only does not seem to work with the FOR UPDATE clause.