I'm getting my first experience with Oracle and TOAD (I know SSMS). I came across this "%Type" next to an input parameter in an update proc开发者_JS百科edure and I have no idea what it is or what it means. I found links on Google related to "%Rowtype". Is the same thing or something entirely different?
If this is vague, I apologize. As always, thanks for the help.
Oracle (and PostgreSQL) have:
- %TYPE
- %ROWTYPE
%TYPE
%TYPE
is used to declare variables with relation to the data type of a column in an existing table:
DECLARE v_id ORDERS.ORDER_ID%TYPE
The benefit here is that if the data type changes, the variable data type stays in sync.
Reference: http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/fundamentals.htm#i6080
%ROWTYPE
This is used in cursors to declare a single variable to contain a single record from the resultset of a cursor or table without needing to specify individual variables (and their data types). Ex:
DECLARE
CURSOR c1 IS
SELECT last_name, salary, hire_date, job_id
FROM employees
WHERE employee_id = 120;
-- declare record variable that represents a row fetched from the employees table
employee_rec c1%ROWTYPE;
BEGIN
-- open the explicit cursor and use it to fetch data into employee_rec
OPEN c1;
FETCH c1 INTO employee_rec;
DBMS_OUTPUT.PUT_LINE('Employee name: ' || employee_rec.last_name);
END;
/
Apart from the purpose pointed by OMG Ponies, %TYPE
is also used for inheriting the same data type used by a previously declared variable.
The syntax is :
DECLARE
L_num NUMBER(5,2) NOT NULL default 3.21;
L_num_Test L_num%TYPE := 1.123;
So there is no need to declare the data type for the second variable i.e L_num_Test
.
Comment if anyone needs further clarification regarding this topic.
Reference: https://docs.oracle.com/cd/B19306_01/appdev.102/b14261/fundamentals.htm#BEIIGBBF
some example
set serveroutput on
DECLARE
var1 table_a.id%TYPE;
var2 table_a.value%TYPE;
var3_row table_a%ROWTYPE;
BEGIN
SELECT id,value
INTO var1, var2
FROM table_a
WHERE id= 8 AND ROWNUM<=1;
SELECT id+100,value INTO var3_row from table_A where rownum=1;
INSERT INTO table_a VALUES var3_row;
dbms_output.put_line('this is a test');
dbms_output.put_line(var1);
dbms_output.put_line(var2);
NULL; -- do something useful here
EXCEPTION
WHEN NO_DATA_FOUND THEN
NULL; -- do something appropriate here
WHEN TOO_MANY_ROWS THEN
NULL; -- do something appropriate here
END;
/
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