I have a sub query that returns one column, showing as GroupType, I then want to do a CASE function on this result within the main query, however I get an invalid column name when using the CASE statement.
Can i do this in SQL to do I have to refer to it by a different name
SELECT CASE
WHEN
(
SELECT column
FROM othertable
) = 1
THEN '1'
ELSE '2'
END
FROM mytable
To reuse the subquery result:
SELECT subvalue, CASE subvalue WHEN 1 THEN 1 ELSE 2 END
FROM (
SELECT (
SELECT column
FROM othertable
) AS subvalue
FROM mytable
) q
Related
I am having problem in part of my code anyway to do this
Only one expression can be specified in the select list when the subquery is not introduced with EXISTS. The update part is working but how to use insert into to calculate if a condition is not meant it will insert.
IF
/* CHECKLIST TO UPDATE*/
(NOT EXISTS
(SELECT *
FROM ENERGY.D_ENERGY_REFERENCE D_ENERGY_REFERENCE
,ENERGY.D_CHECK_LIST D_CHECK_LIST
WHERE D_ENERGY_REFERENCE.ID = D_CHECK_LIST.ID
AND D_ENERGY_REFERENCE.REFERENCE = 19051
)
)
BEGIN
INSERT INTO DB.D_ENERGY_REFERENCE(ID, REFERENCE_NO, REFERENCE,VALUE_INTEGER)
(SELECT ID,
(SELECT ISNULL(MAX(REFERENCE_NO), 0) + 1 FROM DB.D_ENERGY_REFERENCE),
19051, (SELECT D_CHECK_LIST.ID,
CASE
WHEN CAST(COUNT(CASE WHEN D_CHECK_LIST.EVALUATION NOT IN (0,1) THEN EVALUATION ELSE NULL END) AS FLOAT) = 0 THEN NULL
ELSE
(
CAST(COUNT(CASE WHEN D_CHECK_LIST.EVALUATION IN (2, 3, 50001, 50003, 50004, 50005, 50006, 50020, 50027, 50028) THEN EVALUATION ELSE NULL END) AS FLOAT)
/
CAST(COUNT(CASE WHEN D_CHECK_LIST.EVALUATION NOT IN (0,1) THEN EVALUATION ELSE NULL END) AS FLOAT)
) * 100
END FROM DB.D_CHECK_LIST
GROUP BY D_CHECK_LIST.ID)
FROM DB.D_ENERGY_REFERENCE D_ENERGY_REFERENCE
WHERE D_ENERGY_REFERENCE.ID = ID AND D_ENERGY_REFERENCE.REFERENCE = 19051
GROUP BY D_ENERGY_REFERENCE.ID
)
END
Can you please check this following part in the sub query of your script-
.......
19051,
(
SELECT
D_CHECK_LIST.ID, -- This is the column 1
CASE
WHEN -- Here you are generating column 2 in the sub query
......
)
Here you are selecting 2 column - one is "D_CHECK_LIST.ID" and other one is generation through CASE WHEN statement. I think you should SELECT any 1 column from those 2 column. If both are required, you can use separate Sub query for that.
The ERROR code "Only one expression can be specified in the select list when the subquery is not introduced with EXISTS" is self explanatory that you can not implement a Sub Query with more than 1 column selected unless the Sub Query is using inside EXISTS method.
What is better approach to check existence of an object in database?
select count(id) as count from my_table where name="searchedName";
OR
select id from my_table where name="searchedName";
And then check if count > 0 or the object is not null (ORM logic)
EDIT:
select id to be valid for Oracle.
The idea should be to that we only need to find one record in order to say that such record exists. This can be done with an EXISTS clause in standard SQL.
select exists (select * from mytable where name = 'searchedName');
returns true if the table contains a record with 'searchedName' and false otherwise.
If you want 0 for false and 1 for true instead (e.g. if the DBMS does not support booleans):
select case when exists (select * from mytable where name = 'searchedName')
then 1 else 0 end as does_exist;
You say you want this for Oracle. In Oracle you can use above query, but you'd have to select from the table dual:
select case when exists (select * from mytable where name = 'searchedName')
then 1 else 0 end as does_exist
from dual;
But for Oracle we'd usually use rownum instead:
select count(*) as does_exist
from mytable
where name = 'searchedName'
and rownum = 1; -- to find one record suffices and we'd stop then
This also returns 1 if the table contains a record with 'searchedName' and 0 otherwise. This is a very typical way in Oracle to limit lookups and the query is very readable (in my opinion).
I'd just call:
select id from my_table where name='searchedName';
Making sure there is an index for the name column.
And then check whether or not the result is empty.
Try with IF EXISTS (
if exists (select 1 from my_table where name = "searchedName")
begin
....
end
query 1
(select count(*) from CALENDAR)
it returns 15
query 2
(select value from PARAMETER where name = 'PLAN_HORIZON')
it returns 15 too only when my programs runs without error. if error occurs,
it returns 10 or other values.
this↓ is wrong sql, but i want a single query which returns True or False.
select if (query1 == query2)
How can I define 2 sql has same result in a query?
The following SQL statement returns 0 or 1. It runs with SQL Server
SELECT CASE WHEN (select count(*) from CALENDAR) = (select value from PARAMETER where name = 'PLAN_HORIZON') THEN 1 ELSE 0 END
Something like this:
select count(*) = 0
from (
select count(*)
from calendar
except
select value
from parameter
where name = 'PLAN_HORIZON'
) t
You didn't specify your DBMS, but the above is standard SQL.
Try this query !
SELECT
CASE
WHEN (select count(*) from CALENDAR) = (select value from PARAMETER
where name = 'PLAN_HORIZON')
THEN true
ELSE false
END ;
I have to create a new table and inside should be the columns I get from the CASE statement. I do not need the rest of the columns resulting from the select statement
for example:
CREATE TABLE test
AS (
SELECT a.id, ...
CASE WHEN a.id = 1 THEN 2
ELSE 0
END as LegalType
FROM table a, ...
WHERE ...);
now my question how can I select only the column LegalType from the CASE statement? I do not want to have column a.id
You can SELECT INTO
SELECT CASE WHEN a.id = 1 THEN 2 ELSE 0 END as LegalType
....
INTO test
FROM table a
WHERE 1=1);
This will create you a table based on the data returned in the SELECT. see https://msdn.microsoft.com/en-GB/library/ms188029.aspx
I'm trying to create the following WHERE clause:
AND CASE #SomePRarmeter
WHEN 'this' THEN
user_id IN (SELECT * FROM dbo.func_Id1(#User))
WHEN 'that' THEN
user_id IN (SELECT user_id from dbo.func_Ids2(#OrgsForReporter)
END
But I'm getting an error: Incorrect syntax near the keyword 'IN' (in the first condition) , although separately both of those conditions work. What would be the correct way to make such a statement work?
Thanks!
Try
AND (
(#SomePRarmeter = 'this' AND user_id IN (SELECT * FROM dbo.func_Id1(#User)))
OR
(#SomePRarmeter = 'that' AND user_id IN user_id IN (SELECT user_id from dbo.func_Ids2(#OrgsForReporter)))
)
You are doing select * in a subquery. You need to return only one column:
(SELECT * FROM dbo.func_Id1(#User))
to this:
(SELECT YOUR_USER_ID_COLUMN FROM dbo.func_Id1(#User))
A case statement must result in a value, not an expression. So this won't work:
select case when 1=1 then 1 in (1,2,3) end
But this will work;
select case when 1=1 then 1 end
The value can be the result of a subquery. So one solution would be to rewrite the where clause like:
CASE #SomePRarmeter
WHEN 'this' THEN
(SELECT count() FROM dbo.func_Id1(#User) f where f.user_id = t.user_id))
WHEN 'that' THEN
(SELECT count() from dbo.func_Ids2(#OrgsForReporter) f where f.user_id = t.user_id))
END > 1
Now it returns the number of matching rows. You can then filter with case ... end > 1.
I'd break this out:
IF 'this'
SELECT
...
WHERE user_id IN (SELECT * FROM dbo.func_Id1(#User))
ELSE IF 'that'
SELECT
...
WHERE user_id IN (SELECT user_id from dbo.func_Ids2(#OrgsForReporter))
CASE ... END returns an expression, not a piece of literal SQL code. Rather than:
AND CASE foo WHEN bar THEN bla=ble END -- Wrong
... you have to use this:
AND bla = CASE foo WHEN bar THEN ble END -- Right
In your case, you can do something on this line:
-- Untested
AND (
(#SomePRarmeter='this' AND user_id IN (SELECT * FROM dbo.func_Id1(#User)))
OR (#SomePRarmeter='that' AND user_id IN (SELECT user_id from bo.func_Ids2(#OrgsForReporter))
)