I'm working on this problem for several days. I have a oracle database.
The problem must be resolved in one query. No Function, Pocedure, ...
I want to make a select. When he has results, post them. Else there should be "empty result".
select case
when count(*) = 0
then 'no Entry'
else MAX(Member)--all Members should be here
END as Member
from tableMember
where Membergroup = 'testgroup';
The problem is that Oracle wants an Agregat function by the else. So I only get one value if the result is not "no entry". I need all values.
Everybody who can help me is welcome and makes me happy.
not sure what do you try to achieve, perhaps this
select member from tablemember where Membergroup = 'testgroup'
union
select 'no Entry'
from dual
where NOT EXISTS ( select member from tablemember where membergroup = 'testgroup')
;
There's no need for two aggregate queries, you just need to check whether max(member) is null. I'd do it this way to make it clear what's going on.
select case when max_member is null then 'no entry' else max_member end as member
from ( select max(member) as max_member
from tablemember
where membergroup = 'testgroup'
)
If, however, you want to return all members you can do something like the following:
select member
from tablemember
where membergroup = 'testgroup'
union all
select 'no entry'
from dual
where not exists ( select 1 from tablemember where membergroup = 'testgroup')
If you RIGHT JOIN your query with a query for the empty set you will always get one row and will get all the rows if your query returns data. This is less expensive (faster) than a UNION or UNION ALL with a NOT EXISTS because it does not require multiple scans of the data.
SELECT nvl(a.member,b.member) member
FROM (SELECT member FROM tablemember WHERE membergroup='????') a
RIGHT JOIN (SELECT 'no Entry' member FROM dual) b ON 1=1;
Test Environment:
DROP TABLE tablemember;
CREATE TABLE tablemember AS
(
SELECT TO_CHAR(level) member
, DECODE(mod(level, 5), 0, 'testgroup', 'othergroup') membergroup
FROM dual CONNECT BY level <= 50
);
You can use some aggregate functions and NVL for achieve you goal:
SELECT MIN('VALUE 1') AS p1, MIN('VALUE 2') AS p2 FROM DUAL WHERE 1=0
result of this query is:
NULL, NULL
next, replace empty values by desired strings:
SELECT
NVL(MIN('1'), 'empty value 1') AS p1,
NVL(MIN('STRING VALUE'), 'empty value 2') AS p2,
NVL(MIN((select 'subquery result' from dual)), 'empty subquery result') as p3
FROM
DUAL
WHERE
1=0
But, you can't mix numbers and strings in fields.
Try this:
DECLARE C INTEGER;
SELECT COUNT(*) INTO C FROM tableMember WHERE Membergroup = 'testgroup';
IF C > 0
THEN
SELECT * FROM tableMember;
ELSE
SELECT 'No results!' FROM tableMember;
END IF;
Related
I'm having a hard time with sql and probably this will look stupid but it shows what I am trying to achieve.
SELECT
CASE WHEN ( ( SELECT 1 FROM table_1 WHERE = condition ) IS NULL ) THEN
SELECT 'No result'::varchar
ELSE
SELECT
val_1,
val_2,
val_3
FROM
table_1
END;
A null answer is not good in my situation, I can't just use the sub-query as the main. And even if I could that would still leave the question open if the two tables were NOT the same like:
SELECT
CASE WHEN ( ( SELECT 1 FROM table_1 WHERE = condition ) IS NULL ) THEN
SELECT 'No result'::varchar
ELSE
SELECT
val_1,
val_2,
val_3
FROM
table_2 --TABLE REPLACED!
END;
As CASE-WHEN only works for one column it would be horrifying to have 20 of them with the same condition. Any help is appreciated! Thanks!
So you want to SELECT the table_log and if the result is not NULL show it to the client and if it is NULL show a message?
I created a fake table for testing. What you are looking for is the last SELECT-statement:
DROP TABLE IF EXISTS table_log;
CREATE TEMP TABLE table_log (
id INTEGER
,log_info VARCHAR)
;
INSERT INTO table_log VALUES
(1, 'test_entry')
;
ANALYZE table_log;
SELECT
COALESCE(b.log_info, 'No changes done!') AS log_info
FROM
(SELECT 'Fake-Data') a
LEFT OUTER JOIN (SELECT * FROM table_log WHERE id = 1) b ON (1=1);
If the given id = 1, you get the result, if it is something else (because it is not in the test-table) the premade message is given.
Here is a link to the db<>fiddle.
So i have a union query like:
select count(id)
from table 1
where membernumber = 'x'
and castnumber = 'y'
union
select count(id)
from table 1
where membernumber = 'x'
and castnumber = 'y'
union
etc...
There will be over 200 unions coming from a list 2x 200 table with values for x and y in each row. So each union query has to get the value of x and y from the corresponding row (not in any particular order).
How can i achieve that ?
Thanks
Try this:
DECLARE GLOBAL TEMPORARY TABLE
SESSION.PARAMETERS
(
MEMBERNUMBER INT
, CASTNUMBER INT
) DEFINITION ONLY WITH REPLACE
ON COMMIT PRESERVE ROWS NOT LOGGED;
-- Insert all the the constants in your application with
INSERT INTO SESSION.PARAMETERS
(MEMBERNUMBER, CASTNUMBER)
VALUES (?, ?);
-- I don't know the meaning of the result you want to get
-- but it's equivalent
select distinct count(t.id)
from table1 t
join session.parameters p
on p.membernumber = t.membernumber
and p.castnumber = t.castnumber
group by t.membernumber, t.castnumber;
I have a table having below data , total 8 rows here sample for 3 rows -
now I transformed the query using case statement to this using below query -
select
case when entity ='PRODUCT' then prd_table_main end P_main_prd ,
case when entity ='PRODUCT' then prd_table_sec end P_sec_prd,
case when entity ='CUSTOMER' then cus_table_main end P_main_cus ,
case when entity ='CUSTOMER' then cus_table_sec end p_sec_cus,
case when entity ='PROFIT' then prof_table_main end p_main_prof ,
case when entity ='PROFIT' then prof_table_sec end p_sec_prof
from (
select * from above table);
Now I want to have the o/p as in one row removing all the nulls. Basically I want to create a cursor and pass the value of tables to be used in the procedure as p_main_prd or p_sec_prd or the remaining ones as the requirement.
You are almost there, you just need to aggeregate:
select MAX( case when entity = 'product' then table1 end ) AS P_main_prd,
MAX( case when entity = 'product' then table2 end ) AS P_sec_prd,
MAX( case when entity = 'customer' then table1 end ) AS P_main_cus,
MAX( case when entity = 'customer' then table2 end ) AS p_sec_cus,
MAX( case when entity = 'profit' then table1 end ) AS p_main_prof,
MAX( case when entity = 'profit' then table2 end ) AS p_sec_prof
from table_name;
or use PIVOT:
SELECT prd_p_main AS p_main_prd,
prd_p_sec AS p_sec_prd,
cus_p_main AS p_main_cus,
cus_p_sec AS p_sec_cus,
prof_p_main AS p_main_prof,
prof_p_sec AS p_sec_prof
FROM table_name
PIVOT (
MAX( table1 ) AS p_main,
MAX( table2 ) AS p_sec
FOR entity IN (
'product' AS prd,
'customer' AS cus,
'profit' AS prof
)
)
Which, for the sample data:
CREATE TABLE table_name ( entity, table1, table2 ) AS
SELECT 'product', 'prd_table_main', 'prd_table_sec' FROM DUAL UNION ALL
SELECT 'customer', 'cus_table_main', 'cus_table_sec' FROM DUAL UNION ALL
SELECT 'profit', 'prof_table_main', 'prof_table_sec' FROM DUAL
Outputs:
P_MAIN_PRD
P_SEC_PRD
P_MAIN_CUS
P_SEC_CUS
P_MAIN_PROF
P_SEC_PROF
prd_table_main
prd_table_sec
cus_table_main
cus_table_sec
prof_table_main
prof_table_sec
db<>fiddle here
Maybe you can try UNPIVOT. I'm not an expert on this, so I can only help you by giving you directions. Check this out, probably this will help you out, or at least show you another way:
Oracle Unpivot
I have a script that extracts transactions and their details from a database. But my users complain that the file size being generated is too large, and so they asked for certain transactions to be just summed up/consolidated instead if they are of a certain classification, say Checking Accounts. That means there should only be one line in the result set named "Checking" which contains the sum of all transactions under Checking Accounts. Is there a way for an SQL script to go like:
CASE
WHEN Acct_class = 'Checking'
then sum(tran_amount)
ELSE tran_amount
END
I already have the proper GROUP BY and ORDER BY statements, but I can't seem to get my desired output. There is still more than one "Checking" line in the result set. Any ideas would be very much appreciated.
Try This,
Select sum(tran_amount) From tran_amount Where Acct_class = 'Checking'
You can try to achieve this using UNION ALL
SELECT tran_amount, .... FROM table WHERE NOT Acct_class = 'Checking'
UNION ALL
SELECT SUM(tran_amount), .... FROM table WHERE Acct_class = 'Checking' GROUP BY Acct_class, ...;
hi you can try below sql
select account_class,
case when account_class = 'saving' then listagg(trans_detail, ',') within group (order by emp_name) -- will give you all details transactions
when account_class = 'checking' then to_char(sum(trans_detail)) -- will give you only sum of transactions
end as trans_det from emp group by account_class;
Or, if your desired output is getting either the sum, either the actual column value based on another column value, the solution would be to use an analytical function to get the sum together with the actual value:
select
decode(acct_class, 'Checking', tran_amount_sum, tran_amount)
from (
select
sum(tran_amount) over (partition by acct_class) as tran_amount_sum,
tran_amount,
acct_class
from
YOUR_TABLE
)
You can try something like the following, by keeping single rows for some classes, and aggregating for some others:
with test (id, class, amount) as
(
select 1, 'a' , 100 from dual union all
select 2, 'a' , 100 from dual union all
select 3, 'Checking', 100 from dual union all
select 4, 'Checking', 100 from dual union all
select 5, 'c' , 100 from dual union all
select 6, 'c' , 100 from dual union all
select 7, 'c' , 100 from dual union all
select 8, 'd' , 100 from dual
)
select sum(amount), class
from test
group by case
when class = 'Checking' then null /* aggregates elements of class 'b' */
else id /* keeps elements of other classes not aggregated */
end,
class
I have a query like this:
select data_name
into v_name
from data_table
where data_table.type = v_t_id
Normally, this query should return exactly one row. When there's no match on v_t_id, the program fails with a "No data found" exception.
I know I could handle this in PL/SQL, but I was wondering if there's a way to do this only in a query. As a test, I've tried:
select case
when subq.data_name is null then
'UNKNOWN'
else
subq.data_name
end
from (select data_name
from data_table
where data_table.type = '53' /*53 does not exist, will result in 0 rows. Need fix this...*/
) subq;
...but this will obviously not work (because subq being empty is not the same as subq.data_name is null). Is this even possible or should I just check in my PL/SQL solution?
(oracle 10g)
There's ways to make this simpler and cleaner, but this basically spells out the technique:
SELECT data_name
FROM data_table
WHERE data_table.type = v_t_id
UNION ALL
SELECT NULL AS data_name
FROM dual
WHERE NOT EXISTS (
SELECT data_name
FROM data_table
WHERE data_table.type = v_t_id
)
When the first part of the union is empty the second will contain a row, when the first part is not empty, the second will contain no rows.
If the query is takes to much time, use this one:
SELECT * FROM (
SELECT data_name
FROM data_table
WHERE data_table.type = v_t_id
UNION ALL
SELECT NULL AS data_name
FROM dual
) WHERE data_name is not null or ROWNUM = 1
I would prefer to handle the exception. However, this would work as you specify:
select min(data_name) data_name
into v_name
from data_table
where data_table.type = v_t_id
Note that this also "works" if the query returns more than 1 row - i.e. TOO_MANY_ROWS is not raised.
select coalesce(data_table.data_name, d.data_name) data_name
into v_name
from
(SELECT 'UNKNOWN ' as data_name FROM DUAL) d
LEFT JOIN data_table
ON data_table.type = v_t_id
or a.data_table.data_name is null
Here is my simple solution using LEFT OUTER JOIN:
CREATE TABLE data_table(data_name VARCHAR2(20), data_type NUMBER(2));
INSERT INTO data_table(data_name, data_type) VALUES('fifty-one', 51);
SELECT coalesce(data_name, 'unknown')
FROM dual
LEFT OUTER JOIN (SELECT data_name FROM data_table WHERE data_type = 53) o
ON 1 = 1;
SELECT coalesce(data_name, 'unknown')
FROM dual
LEFT OUTER JOIN (SELECT data_name FROM data_table WHERE data_type = 51) o
ON 1 = 1;
https://stackoverflow.com/a/4683045/471149 answer is nice, but there is shorter solution
select * from my_table ce, (select 150 as id from dual) d
where d.id = ce.entry_id (+)
If you always expect zero or one row then you can use a group function i.e.:
select dump(max(dummy)) from dual
where dummy = 'Not Found'
You will always get at least one row and a value of NULL in the case where the record is not found.