i am trying to simply the following union query .Basically i am trying to get all the possible values from same table different column and i have to take value which are not equal to no then replace them with specific text when they are from respective column.
select 'a' from Mytable where a!='no' and id='1'
union
select 'b' from Mytable where b!='no' and id='1'
union select 'c' from Mytable where c!='no' and id='1'
so my table structure will be
id Acolumn BColumn Ccolumn
1 123a no 345v
so my expected result is
a c
so please suggest me to simplify this query thanks in advance
According to what you've written, this might be OK.
select case when a <> 'no' and id = '1' then 'a'
when b <> 'no' and id = '1' then 'b'
when c <> 'no' and id = '1' then 'c'
end
from mytable
where (a <> 'no' and id = '1')
or (b <> 'no' and id = '1')
or (c <> 'no' and id = '1')
Related
I have to do a select query to create a view with specific criteria.
I have multiple tables which contains many many columns and lines.
However, I have extracted a value to use as my key (e.g.: id). I have 7000+ of those unique keys that I extracted from all my tables with the function UNION to avoid duplicates.
Now, I want to add a column INDICATOR_1 which will affect the value YES or NO based on criteria.
This is where I struggle.
I need to find the line in those tables that contain the id. After that, I'd like to check, always in that line, if the field XYZ contains the value 'N' (example). If yes, affect the value 'YES' to INDICATOR_1, else it's no.
In a matter of pseudo-code, what I want to do looks like this :
CASE
WHEN id = (id from table_1) AND (if table_1.xyz = 'N')
THEN 'YES'
ELSE 'NO'
END AS INDICATOR_1
I don't know if I'm clear enough, but your help will be greatly appreciated.
If I understand correctly, you want a separate indicator for each table. Something like this:
select i.*,
(case when exists (select 1
from table1 t1
where t1.id = i.id and t1.xyz = 'N'
)
then 'YES' else 'NO'
end) as indicator_1,
(case when exists (select 1
from table2 t2
where t2.id = i.id and t2.xyz = 'N'
)
then 'YES' else 'NO'
end) as indicator_2,
. . .
from (<your id list here>) i
I think you should fix this in the union, where you have all the data you need. You probably have something like:
SELECT Id
FROM table_1
UNION
SELECT Id
FROM table_2
How about selecting the information you want as well (I use distinct here to clarify):
SELECT DISTINCT Id
, CASE WHEN table_1.xyz = 'N' THEN 'N'
ELSE 'Y'
END INDICATOR_1
FROM table_1
This can lead to more records than you had, if id's can have records of both flavours exist. We can fix that with a row number in an outer query. You end up with something like:
SELECT Id
, INDICATOR_1
FROM (
SELECT Id
, INDICATOR_1
, ROW_NUMBER()OVER(PARTITION BY ID ORDER BY CASE WHEN INDICATOR_1 ='N' THEN 0 ELSE 1 END) RN
FROM (
SELECT Id
, CASE WHEN table_1.xyz = 'N' THEN 'N'
ELSE 'Y'
END INDICATOR_1
FROM table_1
UNION
...
) T
) S
WHERE S.RN = 1
You can in fact shorten that by using the inner most case expression in the ROW_NUMBER expression.
My server was crashed, damaging my database. In one of my tables I have an academic_quality column where I store school grades like A, B, C+, D. Somehow, my grades are not distributed through other columns on some rows. I thought I could create a conditional clause and create a new column, academic_quality_new, and update it after checking other columns. I tried the following query but it did not work.
SELECT academic_quality, acceptance_rate, undergrads, setting, environment, degrees_offered,
CASE WHEN (academic_quality OR acceptance_rate OR undergrads OR setting OR environment OR degrees_offered) = 'A' THEN INSERT 'A' INTO academic_quality_new
CASE WHEN (academic_quality OR acceptance_rate OR undergrads OR setting OR environment OR degrees_offered) = 'C' THEN INSERT 'B' INTO academic_quality_new
FROM [school_List_V4]
Any help would be appreciated!
You can try by adding case..when for all available grades.
First you can execute select query and check result
select * ,
case when academic_quality = 'A' OR acceptance_rate = 'A' then 'A'
else case when academic_quality ='B' OR acceptance_rate = 'B' then 'B'
else case when academic_quality = 'C' OR acceptance_rate = 'C' then 'C'
else '--'
end
end
end
from table1
then try this update query, it will update new column. If 2 cases are true then it will take first case, so case on grades should be from highest to lowest.
update table1
set new =
case when academic_quality = 'A' OR acceptance_rate = 'A' then 'A'
else case when academic_quality ='B' OR acceptance_rate = 'B' then 'B'
else case when academic_quality = 'C' OR acceptance_rate = 'C' then 'C'
else '--'
end
end
end
and final updated new column is select * from table1
academic_quality | acceptance_rate | new
A | NULL | A
NULL | B | B
NULL | NULL | --
A | B | A
C | B | B
I have a huge query and I am wondering if it is in Oracle possible
to get the result of a case-when-statement and use it for comparison? My CASE-STATEMENT is declared in the Select-Statement and it looks like this.
SELECT........
(CASE
WHEN (Select 1 from DUAL) = 1 THEN 'TEST'
ELSE 'TEST2'
END) AS TEST;
Now I want to get the result of this case-statement and use it in the where part? Is it possible? (Sry this may be a dumb question)
If you define your CASE statement in either an inline-view or a common table expression (aka WITH clause), you can refer to it by whatever alias you give it.
For example (inline-view):
SELECT ...
FROM ( SELECT .....
(CASE
WHEN (Select 1 from DUAL) = 1 THEN 'TEST'
ELSE 'TEST2'
END) AS TEST
FROM...
) v
WHERE v.test = 'TEST2';
As a common table expression, it would be:
WITH cte AS ( SELECT........
(CASE
WHEN (Select 1 from DUAL) = 1 THEN 'TEST'
ELSE 'TEST2'
END) AS TEST
FROM ... )
SELECT ...
FROM cte
WHERE test = 'TEST2';
You can use a case statement in the where clause, for eg.:
select * from table
where table.field = (CASE
WHEN (Select 1 from DUAL) = 1 THEN 'TEST'
ELSE 'TEST2'
END)
This will compare the value returned from the case statement with the table field.
I am trying to select different values that depend on different conditions, but I don't exactly know, how one can achieve this in SQL/Oracle..
Here is an example:
SELECT VALUE (I dont exactly know what to write here)
FROM
(SELECT
(CASE
WHEN (Select 1 from DUAL) = 1 THEN 'TEST'
WHEN (Select 1 from DUAL) = 0 THEN 'TEST1'
WHEN (Select 1 from DUAL) = 0 THEN 'TEST2'
ELSE 'N/A'
END)
FROM DUAL);
I want to print different results according to the conditions...For instance, in the example above it should print "TEST"
You need to provide an alias to the CASE statement:
SELECT alias_for_your_case_value
FROM (
SELECT CASE (Select 1 from DUAL)
WHEN 1 THEN 'TEST'
WHEN 0 THEN 'TEST1'
WHEN 0 THEN 'TEST2'
ELSE 'N/A'
END AS alias_for_your_case_value
FROM DUAL
);
I'm trying to do something similar to this:
CASE
WHEN number IN (1,2,3) THEN 'Y' ELSE 'N' END;
Instead I want to have a query in the place of the list, like so:
CASE
WHEN number IN (SELECT num_val FROM some_table) THEN 'Y' ELSE 'N' END;
I can't seem to get this to work. Also, here is an example of the query.
SELECT number, (CASE
WHEN number IN (SELECT num_val FROM some_table) THEN 'Y' ELSE 'N' END) AS YES_NO
FROM some_other_table;
Yes, it's possible. See an example below that would do what you are intending. The difference is that it uses EXISTS instead of IN.
SELECT a.number,
(CASE WHEN EXISTS (SELECT null FROM some_table b where b.num_val = a.number)
THEN 'Y'
ELSE 'N'
END) AS YES_NO
FROM some_other_table a;
EDIT:
I confess: I like the answers given by the others better personally.
However, there will be a difference between this query and the others depending on your data.
If for a value number in the table some_other_table you can have many matching entries of num_val in the table some_table, then the other answers will return duplicate rows. This query will not.
That said, if you take the left join queries given by the others, and add a group by, then you won't get the duplicates.
I suggest using an OUTER JOIN instead of trying to use a subquery in a CASE expression:
SELECT t.NUMBER,
CASE
WHEN s.NUM_VAL IS NOT NULL THEN 'Y'
ELSE 'N'
END AS YES_NO
FROM SOME_OTHER_TABLE t
LEFT OUTER JOIN SOME_TABLE s
ON s.NUM_VAL = t.NUMBER
Best of luck.
Seems like you just need to join the tables and do a decode.
with x as
(
select 1 as num from dual
union
select 2 as num from dual
union
select 3 as num from dual
),
y as
(
select 1 as num from dual
union
select 2 as num from dual
union
select 4 as num from dual
)
select x.num, decode(y.num, null, 'N','Y') as yes_no
from x
left outer join y on (x.num = y.num)
Output:
NUM YES_NO
1 Y
2 Y
3 N
You can use subquery in case statement:
select
case dummy
when 'X' then (select 'TRUE' from dual)
else 'FALSE'
end TEST
from dual;
TEST
TRUE
select
case (select 'XXX' from dual)
when 'XXX' then 'TRUE'
else 'FALSE'
end TEST
from dual;
TEST
TRUE