How to assign value to oracle cursor while iterating?

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by lew , in category: MySQL , 11 days ago

How to assign value to oracle cursor while iterating?

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1 answer

by dalton_moen , 10 days ago

@lew 

You cannot assign a value directly to an Oracle cursor while iterating through it. Cursors in Oracle are read-only and cannot be updated or modified while iterating through them.


If you need to modify the data being retrieved by a cursor, you will need to fetch the data into a variable or array and then modify the values in the variable or array.


For example, you can use a loop to fetch each row from the cursor into a variable and then update the values in the variable:

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DECLARE
  CURSOR c_emp IS
    SELECT employee_id, first_name, last_name
    FROM employees;
  
  v_employee_id   employees.employee_id%TYPE;
  v_first_name    employees.first_name%TYPE;
  v_last_name     employees.last_name%TYPE;
BEGIN
  OPEN c_emp;
  
  LOOP
    FETCH c_emp INTO v_employee_id, v_first_name, v_last_name;
    EXIT WHEN c_emp%NOTFOUND;
    
    -- Modify the values in the variables here
    -- For example, update the last_name to 'Doe'
    v_last_name := 'Doe';
    
    -- Display the modified data
    DBMS_OUTPUT.PUT_LINE('Employee ID: ' || v_employee_id || ', First Name: ' || v_first_name || ', Last Name: ' || v_last_name);
  END LOOP;
  
  CLOSE c_emp;
END;
/


In the above example, we fetch each row from the c_emp cursor into the variables v_employee_id, v_first_name, and v_last_name, and then update the v_last_name variable to 'Doe'. This modified data is then displayed using DBMS_OUTPUT.