I have a task to use cursor to write a function that receives a movie title and then returns pay of actors involved in this movie.
I wrote something like this:
DELIMITER $$
CREATE FUNCTION getPay(movieTitle varchar(90))
RETURNS int;
BEGIN
DECLARE P int;
DECLARE done int DEFAULT FALSE;
DECLARE payCursor CURSOR FOR
(SELECT A.pay FROM actors A JOIN movie M ON M.id=A.movie WHERE M.title=movieTitle);
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;
OPEN payCursor;
loop_read : LOOP
FETCH payCursor INTO P;
IF done THEN
LEAVE loop_read;
END IF;
RETURN P;
END LOOP;
CLOSE payCursor;
END $$
DELIMITER ;
It's not a secret it's not working. I don't know how to return a set, moreover as I've read it's not possible in MariaDB. I tried to create temporary table but it's not good solution if you want to use this function several times. Also I would like to use this function in another task where I have to write a procedure to pay all the actors. I'm not sure I got the idea of cursors.
That function seems to be getting one (any one) row from the query. This would replace the function:
SELECT A.pay
FROM actors A
JOIN movie M ON M.id=A.movie
WHERE M.title=movieTitle)
LIMIT 1;
Or, since it is a function, get rid of the cursor, and have only that in the function.
Related
CREATE OR REPLACE FUNCTION k_w_b_salary(k IN NUMBER, b IN BOOLEAN)
RETURN EMP.ENAME%TYPE IS
names name_table;
BEGIN
IF (b = true) THEN
SELECT ENAME BULK COLLECT INTO names
FROM
(SELECT *
FROM EMP
ORDER BY SAL ASC)
WHERE ROWNUM <= k;
RETURN names;
ELSIF (b = false) THEN
SELECT ENAME BULK COLLECT INTO names
FROM
(SELECT *
FROM EMP
ORDER BY SAL DESC)
WHERE ROWNUM <= k;
RETURN names;
END IF;
END;
And I get this error:
12/9 PL/SQL: Statement ignored
12/16 PLS-00382: expression is of wrong type
20/9 PL/SQL: Statement ignored
20/16 PLS-00382: expression is of wrong type
I have this function that tries to find the best/worst paid employees. But i get the above error.
I think it's something to do with the ROWNUM but I am not sure.
I think the lines the error points out are not the lines with the error.
I had this function writen differently and the lines in the error where pointing to the ROWNUM <= k lines.
I have tried putting a fixed number there (<= 3) for example and I got the same error.
I have no idea what else to try, i can't really understand why this is not working.
It's not obvious to me why this is not working. I think it should work fine but obviously it dousen't.
The code for the table i use is :
CREATE OR REPLACE TYPE name_table IS TABLE OF VARCHAR2(10);
Any help is appreciated!
In the function declaration, you said
RETURN EMP.ENAME%TYPE
I assume the data type of column ENAME in table EMP is some sort of string (VARCHAR2(40) or similar) - right?
In the declarations section, you declare a variable names of data type name_table. You didn't show us the definition of the name_table type (that must be given outside the function, not in it); we can probably assume it is a nested table of some sort. Right? [EDIT - I take that back; you did show us your definition of name_table, at the end of your question.]
In the end, your function returns names. Which is of type name_table. But you said the function returns something else: EMP.ENAME%TYPE. In particular, you said the function returns a scalar data type, but you are returning a collection.
This will not work even if the collection has a single element. A table with a single "record" is not the same data type as the "record" itself - even if an actual table has a single "record" in it.
(And, much more so, when the table has three records in it!)
Rather: It seems that you want a table function: one that returns a table of things. If so, then declare the function that way. Perhaps you want the function to
RETURN NAME_TABLE
(at the top, in the function declaration)
I am using mariadb 10.3.9, and have created a user defined aggregate function (UDAF) and placed in a common_schema. This schema contains my utility functions to be used by other schema/databases on the same server.
The issue is that when calling the UDAF while using any other schema, it always return NULL!
The following is to demonstrate the issue:
CREATE SCHEMA IF NOT EXISTS common_schema;
DELIMITER $$
DROP FUNCTION IF EXISTS common_schema.add_ints $$
CREATE FUNCTION common_schema.add_ints(int_1 INT, int_2 INT) RETURNS INT NO SQL
BEGIN
RETURN int_1 + int_2;
END $$
DROP FUNCTION IF EXISTS common_schema.sum_ints $$
CREATE AGGREGATE FUNCTION common_schema.sum_ints(int_val INT) RETURNS INT
BEGIN
DECLARE result INT DEFAULT 0;
DECLARE CONTINUE HANDLER FOR NOT FOUND RETURN result;
LOOP FETCH GROUP NEXT ROW;
SET result = common_schema.add_ints(result, int_val);
END LOOP;
END $$
DELIMITER ;
Now, calling it this way, returns the result as expected:
USE common_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: 3
Calling it using any other schema, it returns NULL:
USE other_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: null
Am I missing something here? Is there any configuration that is missing?
Appreciate your help.
Reported as a Bug https://jira.mariadb.org/browse/MDEV-18100.
As a workaround, create the UDAF in every schema.
I am working on Oracle 11g Db, Having trouble on writing Oracle syntax.
I am trying to pass a number variable to my select query and populate the select query to a cursor.
Declare yr_nr NUMBER;
Begin
yr_nr := 2014;
SELECT DCD.CCY ID, DCD.CCYCDDSC DSC
FROM CCYDCD DCD, CCYEXC EXC
WHERE DCD.CCY = EXC.CCY
AND EXC.YEARNR = yr_nr
End
This select query returns 80 records. How to rewrite this syntax.
Ok, so what you have here is an anonymous block and everything that happens in the block stays in that block. Kinda like Vegas.
In other words there is nothing to handle the result set from your query. When you do this:
declare
[varName] [type]
begin
select foo from bar where column = var ; <--- this has no place to go!
end
When you are at an sqlPlus prompt, sqlPlus has a default record set handler which then processes the returned record set and prints it to the screen.
When you use any third party tool like JDBC or Oracle's own OCI library those provide a record set handler then parse them to you with the appropriate calls to get the data, e.g.:
rs.getInteger([query],[column] ) //which returns the specific value.
That anonymous block is essentially a stored procedure. So you have to have something to do with the result set. This is the cause of the missing "into" error you are getting.
If on the other hand you did something like:
declare
[varName] [type]
result number ;
begin
select count(foo) into result from bar where column = var ;
end
The variable result would have the value of 80 since that is the number of records fetched.
declare
[varName] [type]
cursor thisCursor(p1 in number ) is select foo from bar where column = p1 ;
begin
for rec in thisCursor(varName) loop
If rec.column = [some value] then
doSomething
end if ;
end loop ;
end
Do this would allow you to do something with the result set.
I am trying to get a ref_cursor to be assigned to a variable inside a for loop then returned at the end of a function. The loop in going through a local cursor if it gets more than 1 result.
I have noted where the error occurs in the code. I am not sure how to create a loop where i can get a ref_cursor for the current point in the loop, assign it to a variable and then return it to the function. Could someone someone help me figure out how to do that? Below is my i-th attempt at logic based of reading around the google searches.
The error is "PLS-00382: expression is of wrong type" and i know that i obviously am not assigning the correct variably type based on this error but the code below with the error is an illustration of what I want to do and what I need help accomplishing.
FUNCTION GET_PARCEL(p_lat in number, p_long in number) return sys_refcursor
IS
v_distance number(10) := 100000000;
v_shortest_dist number(10) := v_distance;
v_centroid SDO_GEOMETRY;
v_rc_ref_cursor sys_refcursor;
v_ref_geom SDO_GEOMETRY := mdsys.SDO_GEOMETRY(2001, 8311, NULL, SDO_ELEM_INFO_ARRAY(1, 1, 1), SDO_ORDINATE_ARRAY(120.3214, -10.7088));
cursor query_cursor is select * from PARCEL_TABLE where code = 20134;
BEGIN
for query_row in query_cursor loop
v_centroid := SDO_GEOM.SDO_CENTROID(query_row.geometry, 0.05);
IF (v_centroid is not null) then
v_distance := SDO_GEOM.SDO_DISTANCE(v_centroid, v_ref_geom, 0.05);
IF v_distance < v_shortest_dist THEN
v_shortest_dist := v_distance;
v_rc_ref_cursor := query_row; -- Error on this line
END IF;
ELSE
DBMS_OUTPUT.PUT_LINE('Centroid is not initialised for some reason.');
END IF;
end loop;
return v_rc_ref_cursor;
END;
As far as I know, you cannot build up a cursor. Cursors are created and maintained by the database with connections to their source data, transaction and session context, and the like.
I would suggest you declare a type, instantiate it, build up the values in the type.
When you are done, create a cursor by selecting * from table (cast (variable as your_type)).
Munge the cursor into a ref_cursor and return that.
Pro tip is to remember you have data in your table and you can use it for logic. Turns out if I use the IDENTIFIER or ROWID of the row/s which i want then i can do a where clause into a ref cursor that looks up by IDENTIFIER or ROWID.
eg.
open v_rc_ref_cursor for select * from PARCEL_TABLE n where n.identifier = query_row.identifier;
super simple stuff :)
When executing the following code, it just says the procedure is completed and doesn't print the infomation i want it to (firstName, lastName) and then the other values from the select query in a table below.
CREATE OR REPLACE PROCEDURE PRINT_ACTOR_QUOTES (id_actor char)
AS
CURSOR quote_recs IS
SELECT a.firstName,a.lastName, m.title, m.year, r.roleName ,q.quotechar from quote q, role r,
rolequote rq, actor a, movie m
where
rq.quoteID = q.quoteID
AND
rq.roleID = r.roleID
AND
r.actorID = a.actorID
AND
r.movieID = m.movieID
AND
a.actorID = id_actor;
BEGIN
FOR row IN quote_recs LOOP
DBMS_OUTPUT.PUT_LINE('a.firstName' || 'a.lastName');
end loop;
END PRINT_ACTOR_QUOTES;
/
When setting server output on, I get
a.firstNamea.lastName
a.firstNamea.lastName
a.firstNamea.lastName
a.firstNamea.lastName
multiple times!
What is "it" in the statement "it just says the procedure is completed"?
By default, most tools do not configure a buffer for dbms_output to write to and do not attempt to read from that buffer after code executes. Most tools, on the other hand, have the ability to do so. In SQL*Plus, you'd need to use the command set serveroutput on [size N|unlimited]. So you'd do something like
SQL> set serveroutput on size 30000;
SQL> exec print_actor_quotes( <<some value>> );
In SQL Developer, you'd go to View | DBMS Output to enable the DBMS Output window, then push the green plus icon to enable DBMS Output for a particular session.
Additionally, assuming that you don't want to print the literal "a.firstNamea.lastName" for every row, you probably want
FOR row IN quote_recs
LOOP
DBMS_OUTPUT.PUT_LINE( row.firstName || ' ' || row.lastName );
END LOOP;
Ensure that you have your Dbms Output window open through the view option in the menubar.
Click on the green '+' sign and add your database name.
Write 'DBMS_OUTPUT.ENABLE;' within your procedure as the first line.
Hope this solves your problem.
Set Query as below at first line
SET SERVEROUTPUT ON
this statement
DBMS_OUTPUT.PUT_LINE('a.firstName' || 'a.lastName');
means to print the string as it is.. remove the quotes to get the values to be printed.So the correct syntax is
DBMS_OUTPUT.PUT_LINE(a.firstName || a.lastName);
For SQL Developer
You have to execute it manually
SET SERVEROUTPUT ON
After that if you execute any procedure with DBMS_OUTPUT.PUT_LINE('info'); or directly .
This will print the line
And please don't try to add this
SET SERVEROUTPUT ON
inside the definition of function and procedure, it will not compile and will not work.
In Oracle SQL Developer, you can follow steps by steps as the below image:
I am using Oracle SQL Developer,
In this tool, I had to enable DBMS output to view the results printed by dbms_output.put_line
You can find this option in the result pane where other query results are displayed.
so, in the result pane, I have 7 tabs. 1st tab named as Results, next one is Script Output and so on. Out of this you can find a tab named as "DBMS Output" select this tab, then the 1st icon (looks like a dialogue icon) is Enable DBMS Output. Click this icon. Then you execute the PL/SQL, then select "DBMS Output tab, you should be able to see the results there.
All of them are concentrating on the for loop but if we use a normal loop then we had to use of the cursor record variable. The following is the modified code
CREATE OR REPLACE PROCEDURE PRINT_ACTOR_QUOTES (id_actor char)
AS
CURSOR quote_recs IS
SELECT a.firstName,a.lastName, m.title, m.year, r.roleName ,q.quotechar from quote q, role r,
rolequote rq, actor a, movie m
where
rq.quoteID = q.quoteID
AND
rq.roleID = r.roleID
AND
r.actorID = a.actorID
AND
r.movieID = m.movieID
AND
a.actorID = id_actor;
recd quote_recs%rowtype;
BEGIN
open quote_recs;
LOOP
fetch quote_recs into recs;
exit when quote_recs%notfound;
DBMS_OUTPUT.PUT_LINE(recd.firstName||recd.lastName);
end loop;
close quote_recs;
END PRINT_ACTOR_QUOTES;
/