Basic Oracle question - sql

Question

I am new to oracle. When I create a stored procedure using:
CREATE OR REPLACE PROCEDURE PROCEDURE1
AS
BEGIN
SELECT FIRSTNAME,
LASTNAME
INTO FirstName,LastName
FROM EMPLOYEE;
END PROCEDURE1;
i get the following errors:
PL/SQL Statement Ignored
Identifier FIRSTNAME must be declared
ORA-00904 Invalid identifier

Answer 1

You need to declare variables before you attempt to populate them:
CREATE OR REPLACE PROCEDURE PROCEDURE1
AS
FirstName EMPLOYEE.FIRSTNAME%TYPE;
LastName EMPLOYEE.LASTNAME%TYPE;
BEGIN
SELECT FIRSTNAME,
LASTNAME
INTO FirstName,LastName
FROM EMPLOYEE;
END PROCEDURE1;
The %TYPE notation is shorthand for data type declaration that matches the column data type. If that data type ever changes, you don't need to update the procedure.

Answer 2

You need to declare the variables.
CREATE OR REPLACE
PROCEDURE PROCEDURE1 AS
V_FIRSTNAME VARCHAR2(60);
V_LASTNAME VARCHAR2(60);
BEGIN
SELECT FIRSTNAME,LASTNAME
INTO V_FIRSTNAME ,V_LASTNAME
FROM EMPLOYEE;
END PROCEDURE1;
In reply to your comment, SQL statements in PL/SQL block can fetch only 1 record. If you need to fetch multiple records, you will need to store the records in a cursor and process them.
CREATE OR REPLACE
PROCEDURE PROCEDURE1 AS
CURSOR EMP_CUR IS
SELECT FIRSTNAME,LASTNAME
FROM EMPLOYEE;
EMP_CUR_REC EMP_CUR%ROWTYPE;
BEGIN
FOR EMP_CUR_REC IN EMP_CUR LOOP
-- do your processing
DBMS_OUTPUT.PUT_LINE('Employee first name is ' || EMP_CUR_REC.FIRSTNAME);
DBMS_OUTPUT.PUT_LINE('Employee last name is ' || EMP_CUR_REC.LASTNAME);
END LOOP;
END PROCEDURE1;
To explain:
EMP_CUR holds the SQL statement to be executed.
EMP_CUR_REC holds the records that will be fetched by the SQL statement.
%ROWTYPE indicates that the Record will be of the same data type as the row which holds the data
The FOR LOOP will fetch each record, and you can do whatever processing that needs to be done.

Answer 3

I think the "AS" keyword won't work. If it doesn't work, then use "IS".
Rest are fine and very good tips.
If you need any help regarding PL/SQL, then you can have a look at this link. It is very simple and easy to understand;
http://plsql-tutorial.com/
This is my solution to the error which you are getting;
CREATE OR REPLACE PROCEDURE PROCEDURE1 IS
v_FIRSTNAME EMPLOYEE.FIRSTNAME%TYPE;
v_LASTNAME EMPLOYEE.LASTNAME%TYPE;
CURSOR EMPCURSOR IS
SELECT FIRSTNAME, LASTNAME FROM EMPLOYEE;
BEGIN
IF NOT EMPCURSOR%ISOPEN THEN
OPEN EMPCURSOR;
END IF;
LOOP
FETCH EMPCURSOR INTO V_FIRSTNAME,V_LASTNAME;
EXIT WHEN EMPCURSOR%NOTFOUND;
END LOOP;
IF EMPCURSOR%ISOPEN THEN
CLOSE EMPCURSOR;
END;
END PROCEDURE1;
You can also use DBMS_OUTPUT.PUT_LINE(V_FIRSTNAME || ','|| V_LASTNAME), inside the loop to display the output. but in order to do that, you first need to execute the command server output on

Answer 4

In a response to #Sathya's answer above #kayak asked "Can i have something like Select * from Tablename or select firstname,lastname from tablename , like we have in sql server".
Yes, you can do that, but you'll either need to include a WHERE clause or use a cursor. If you include a WHERE clause which limits your results to a single row you could write something like
CREATE OR REPLACE PROCEDURE PROCEDURE1
IS
rowEmployees EMPLOYEE%ROWTYPE;
BEGIN
SELECT *
INTO rowEmployees
FROM EMPLOYEE
WHERE EMPLOYEE_ID = 12345;
END PROCEDURE1;
On the other hand, if you either don't have a WHERE clause because you wish to process all rows in the table, or you have a WHERE clause which doesn't limit your results to a single row you could use a cursor in the following manner:
CREATE OR REPLACE PROCEDURE PROCEDURE1 IS
BEGIN
FOR rowEmployees IN (SELECT *
FROM EMPLOYEE
WHERE EMPLOYEE_ID IN (12345, 67890, 111213, 141516))
LOOP
<do something with rowEmployees here>
END LOOP;
END PROCEDURE1;
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