I would like to have pl-sql like the following:
SELECT ID FROM some-table WHERE
(SELECT MAX(some-expression) FROM another-table = 1) OR
(some-table.ID IN SELECT (SELECT ID FROM one-more-table))
This pseudo-query would select all IDs from some-table if maximum value of some-expression equals 1 (or filter IDs by one-more-table values otherwise)
How do I properly implement this in PL-SQL ?
Thank you in advance!
Please find the below pl-sql:
DECLARE
v_Column1 NUMBER(4);
v_deptno NUMBER(2);
BEGIN
SELECT MAX(A.DEPTNO)
INTO v_deptno
FROM (SELECT DEPTNO FROM DEPT) A;
SELECT A.EMPNO
INTO v_Column1
FROM EMP A
WHERE A.DEPTNO=v_deptno
OR
A.EMPNO IN ( SELECT EMPNO FROM EMP_2);
END;
/
Related
Let's say that I have a "Rules" table that has a column that contains oracle queries in a varchar2 column:
Row
Query
1
select 'Hardcoded_Tablename_1' tablename, request_id from table_1 where status >= 4 and resolve_date < *some date math goes here*
2
select 'Table_2' tablename, t2.request_id from table_2 t2 join table_1 t1 on t1.request_id = t2.parent_id where t1.status >= 4 and t1.resolve_date < *some date math goes here*
If this were never going to change, I'd just make a view with a union of these queries.
Our requirement is that we be able to add to or to modify these rules on-the-fly at the whims of leadership.
So, what I need is either:
a very smart view (I think impossible) that executes and unions all of these stored query strings
or
a table function that returns the results of the union of these stored query strings. (I think this is the more likely solution)
It will only ever be those two columns: The hardcoded name of the table and the ID of the record.
Can someone help get me started on this?
Thanks
You can use a PIPELINED function.
First create the types:
CREATE TYPE request_data IS OBJECT (tablename VARCHAR2(30), request_id NUMBER);
CREATE TYPE request_list IS TABLE OF request_data;
Then the function:
CREATE FUNCTION get_requests RETURN request_list PIPELINED
IS
BEGIN
FOR r IN (SELECT "QUERY" FROM table_name ORDER BY "ROW")
LOOP
DECLARE
c_cursor SYS_REFCURSOR;
v_tablename VARCHAR2(30);
v_request_id NUMBER;
BEGIN
OPEN c_cursor FOR r."QUERY";
LOOP
FETCH c_cursor INTO v_tablename, v_request_id;
EXIT WHEN c_cursor%NOTFOUND;
PIPE ROW (request_data(v_tablename, v_request_id));
END LOOP;
CLOSE c_cursor;
EXCEPTION
WHEN NO_DATA_NEEDED THEN
CLOSE c_cursor;
RETURN;
END;
END LOOP;
END;
/
Then, if you have the sample data:
CREATE TABLE table_name ("ROW", "QUERY") AS
SELECT 1, q'[select 'Hardcoded_Tablename_1' tablename, request_id from table_1 where status >= 4 and resolve_date < SYSDATE]' FROM DUAL UNION ALL
SELECT 2, q'[select 'Table_2' tablename, t2.request_id from table_2 t2 join table_1 t1 on t1.request_id = t2.parent_id where t1.status >= 4 and t1.resolve_date < SYSDATE]' FROM DUAL
CREATE TABLE table_1 (request_id, status, resolve_date) AS
SELECT 42, 4, SYSDATE - 1 FROM DUAL;
CREATE TABLE table_2 (request_id, parent_id) AS
SELECT 57, 42 FROM DUAL;
Then you can use the function in a table collection expression:
SELECT *
FROM TABLE(get_requests());
Which outputs:
TABLENAME
REQUEST_ID
Hardcoded_Tablename_1
42
Table_2
57
db<>fiddle here
One option might be a function that returns refcursor.
SQL> select * from rules;
CROW QUERY
---------- ----------------------------------------------------------------------------------------------------
1 select 'EMP' tablename, empno from emp where hiredate = (select max(hiredate) from emp)
2 select 'DEPT' tablename, d.deptno from emp e join dept d on d.deptno = e.deptno where e.hiredate = (
select min(hiredate) from emp)
Function creates union of all queries from the rules table and uses it as a source for the refcursor:
SQL> create or replace function f_test return sys_refcursor
2 is
3 l_rc sys_refcursor;
4 l_str clob;
5 begin
6 for cur_r in (select query from rules order by crow) loop
7 l_str := l_str || cur_r.query ||' union all ';
8 end loop;
9 l_str := rtrim(l_str, ' union all ');
10
11 open l_rc for l_str;
12 return l_rc;
13 end;
14 /
Function created.
Testing:
SQL> select f_test from dual;
F_TEST
--------------------
CURSOR STATEMENT : 1
CURSOR STATEMENT : 1
TABL EMPNO
---- ----------
EMP 7876
DEPT 20
SQL>
Im trying to get the compile the below program and im getting not enough values error. This program will give the first 5 maximum and mininum salary holding by employees.
select * from all_tables where table_name like 'EMP5%';
create or replace package ptest1 is
Type rec is record (emin number,salmin number,min_salary number,emax number,salmax number,max_salary number);
TYPE T71 is table of rec;
procedure min_max(inp number, oup out T71);
end;
/
create or replace package body ptest1 as
procedure min_max(inp number, oup out T71)
as
begin
select emin,salmin,min_salary,emax,salmax,max_salary
into oup
from
(select * from
(select empno emin,sal salmin,row_number() over(order by sal asc) min_salary from emp5 where sal is not null) where min_salary <= inp ) t1,
(select * from
(select empno emax,sal salmax,row_number() over(order by sal desc) max_salary from emp5 where sal is not null) where max_salary <= inp) t2
where t1.min_salary = t2.max_salary;
for i in oup.first..oup.last
loop
dbms_output.put_line('Employee number '||oup(i).emin);
end loop;
end;
end ptest1;
/
Im creating a procedure to display the n number of maximum and minimum salary for an employee. If i ll give 5 as input, the query will get me 5 maximum and minimum salary for an employee.
For the above scenario, I have created an object with two columns like below
create type vrec as object(
empno number,
sal number
);
/
Then i created nested table with the help of object type, so that i can use the nested table as out parameter to return all the rows at one short.
create type vrec_type is table of vrec;
/
After the data type creation, im creating a procedure like below
create or replace procedure pro_first_last(input in number,salary out vrec_type)
is
begin
select empno,sal BULK COLLECT INTO salary from (
select empno,sal from
(select empno,sal,rank() over(order by sal asc) min_sal from emp5 where sal is not null) where min_sal <= 5
union all
select empno,sal from
(select empno,sal,rank() over(order by sal desc) max_sal from emp5 where sal is not null) where max_sal <= 5);
for i in salary.first..salary.last
loop
dbms_output.put_line(salary(i).empno);
end loop;
end;
/
When i compiling the above procedure, im getting not enough values. I have also created the object with two columns and in select statement also im returning only two column. Could someone review and help me on this or provide some alternate solution.
You are directly adding empno, sal values into salary (vrec_type object, which can take the values of only object type vrec)
You need to create the object of vrec and then add it into salary as following:
create or replace procedure pro_first_last(input in number,salary out vrec_type)
is
begin
select vrec(empno,sal) -- change in this line
BULK COLLECT INTO salary from (
select empno,sal from
(select empno,sal,rank() over(order by sal asc) min_sal from emp5 where sal is not null) where min_sal <= 5
union all
select empno,sal from
(select empno,sal,rank() over(order by sal desc) max_sal from emp5 where sal is not null) where max_sal <= 5);
for i in salary.first..salary.last
loop
dbms_output.put_line(salary(i).empno);
end loop;
end;
Cheers!!
In my Oracle database there are two tables which are TEMP_HR and PAY_SLIP_APR_16. Both of them have a common column named EMP_ID. TEMP_HR has over 10,000 records and PAY_SLIP_APR_16 has around 6,000 records. I want to know how many EMP_ID of PAY_SLIP_APR_16 is matched with TEMP_HR. If any ID doesn't match then print it. And here is my simple approach but I think its a very bad approach. So any faster method?
DECLARE
INPUT_EMP_NO VARCHAR2(13 BYTE);
INPUT_EMP_ID VARCHAR2(13 BYTE);
ROW_COUNT_1 NUMBER(6,0);
ROW_COUNT_2 NUMBER(6,0);
MATCHED_ID NUMBER;
UNMATCHED_ID NUMBER;
BEGIN
ROW_COUNT_1:=0;
ROW_COUNT_2:=0;
MATCHED_ID:=0;
UNMATCHED_ID:=0;
SELECT COUNT(*) INTO ROW_COUNT_1 FROM PAY_SLIP_APR_16;
SELECT COUNT(*) INTO ROW_COUNT_2 FROM TEMP_HR;
FOR A IN 1..ROW_COUNT_1 LOOP
BEGIN
SELECT EMP_ID INTO INPUT_EMP_ID FROM (SELECT EMP_ID, ROWNUM AS RN FROM PAY_SLIP_APR_16) WHERE RN=A;
FOR B IN 1..ROW_COUNT_2 LOOP
SELECT EMP_NO INTO INPUT_EMP_NO FROM (SELECT EMP_NO, ROWNUM AS RON FROM TEMP_HR) WHERE RON=B;
IF(INPUT_EMP_ID=INPUT_EMP_NO)THEN
MATCHED_ID:=MATCHED_ID+1;
EXIT;
ELSE
CONTINUE;
END IF;
END LOOP;
UNMATCHED_ID:=UNMATCHED_ID+1;
DBMS_OUTPUT.PUT_LINE(INPUT_EMP_ID);
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(INPUT_EMP_ID||' -> '||SQLERRM);
END;
END LOOP;
DBMS_OUTPUT.PUT_LINE('MATCHED -> '||MATCHED_ID);
DBMS_OUTPUT.PUT_LINE('UNMATCHED -> '||UNMATCHED_ID);
END;
Use an outer join filtering for missed joins:
select p.*
from PAY_SLIP_APR_16 p
left join TEMP_HR t on t.EMP_ID = p.EMP_ID
where t.EMP_ID is null
An index on TEMP_HR(EMP_ID) will make this query fly.
You should use SQL sets!
To check which EMP_ID isn't in TEMP_HR you may try this:
select EMP_ID FROM PAY_SLIP_APR_16
where EMP_ID not in (select EMP_NO from TEMP_HR);
Then the other way around:
select EMP_NO FROM TEMP_HR
where EMP_NO not in (select EMP_ID from PAY_SLIP_APR_16);
i have encountered a problem while writing the following code:
create or replace function getashish(dept varchar2) return emp3 as
emp5 emp3;
str varchar2(300);
begin
str := 'select e.last_name,l.city,e.salary from employees e join departments d
on e.department_id = d.department_id join locations l on d.location_id=l.location_id where
d.department_name = :dept';
execute immediate str bulk collect into emp5 using dept;
end;
emp 3 is table of an object as defined below:
create or replace type emp1 as object (lname varchar2(10),city varchar2(10),sal number(10));
create or replace type emp3 as table of emp1;
i am getting the following error while executing the function: SQL Error:
ORA-00932: inconsistent datatypes: expected - got -
thank you for your anticipated help and support.
try declaring emp5 as a datatype of emp1.
emp5 emp1 := emp1();
Please try the below, (added emp1() to your select query inside function and returned emp5)
CREATE OR REPLACE FUNCTION getashish(
dept VARCHAR2)
RETURN emp3
AS
emp5 emp3 := emp3();
str VARCHAR2(300);
BEGIN
str := 'select emp1(e.last_name,l.city,e.salary) from employees e join departments d
on e.department_id = d.department_id join locations l on d.location_id=l.location_id where
d.department_name = :dept';
EXECUTE immediate str bulk collect INTO emp5 USING dept;
RETURN emp5;
END;
/
and the caller block
SELECT * FROM TABLE( CAST(getashish('IT') AS emp3))
UNION
SELECT * FROM TABLE( CAST(getashish('FINANCE') AS emp3));
the function returns a Table, and hence cant be used in SELECT clause, since it is supposed to return one row only, if have to be used in SELECT. Hope you got the concept!
EDIT: Whatever I did!
create table employees
(last_name varchar2(10),salary number,department_id varchar2(10));
create table locations
(location_id varchar2(10),city varchar2(10));
drop table employees;
create table departments
(department_id varchar2(10),location_id varchar2(10),department_name varchar2(10));
insert into employees values ('ASHISH',6000000,'D1');
insert into employees values ('MAHESH',5000000,'D2');
insert into departments values('D1','L1','IT');
insert into departments values('D2','L2','FINANCE');
insert into locations values('L1','Gurgoan');
insert into locations values('L2','Chennai');
commit;
create or replace type emp1 as object (lname varchar2(10),city varchar2(10),sal number(10));
/
create or replace type emp3 as table of emp1;
/
CREATE OR REPLACE FUNCTION getashish(
dept VARCHAR2)
RETURN emp3
AS
emp5 emp3 := emp3();
str VARCHAR2(300);
BEGIN
str := 'select emp1(e.last_name,l.city,e.salary) from employees e join departments d
on e.department_id = d.department_id join locations l on d.location_id=l.location_id where
d.department_name = :dept';
EXECUTE immediate str bulk collect INTO emp5 USING dept;
RETURN emp5;
END;
/
SELECT * FROM TABLE( CAST(getashish('IT') AS emp3))
UNION
SELECT * FROM TABLE( CAST(getashish('FINANCE') AS emp3));
SQL> SELECT * FROM TABLE( CAST(getashish('IT') AS emp3))
2 UNION
3 SELECT * FROM TABLE( CAST(getashish('FINANCE') AS emp3));
LNAME CITY SAL
---------- ---------- ----------
ASHISH Gurgoan 6000000
MAHESH Chennai 5000000