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Return a value if no record is found
(6 answers)
Get 0 value from a count with no rows
(6 answers)
Closed 7 years ago.
I have a simple query:
Select qty from X where id=....;
this query always return 0 or 1 row.
when it return 1 row everything works.
but if it return 0 rows my query fails as qty is used in calculations. (This is acatually a Sub query in Select statment).
I need somehow to make sure the query always return 1 row.
I tried:
Select coalesce(qty,0) from X where id=....;
but it doesn't help as if there are no rows the coalesce is useless.
if no row found it should give 0
How can I fix it?
You can do this:
SELECT COALESCE( (SELECT qty from X where id=....), 0)
if nothing is returned from the inner SELECT statement, COALESCE will give you 0 in the outer SELECT statement.
Select *.a from (
Select qty, 0 as priority from X where id=....
Union
Select 0, 1 as priority
) a
Order By a.priority Asc
Limit 1
This select basically ensures that at least one row is returned by adding an additional row to the end and by adding the limit statement we just return the first row.
So now there is the case where at least one row is found and the additional row is added to the end. In this case the first row found (see ->) will be returned due to the ascending order by priority:
qty priority
-> 1 0
3 0
4 0
. .
0 1
And then there is the case where no row is found but the additional row is returned:
qty priority
-> 0 1
try this.
SELECT COALESCE((SELECT qty
FROM x
WHERE id = #MyIdVar), 1)
If no records found then its return 'No rows found'
if not exists(Select * from table where condition=...)
Begin
Select * from table where condition=...
End
Else
Begin
Select 'No rows found'
End
Whenever you use this you will get record else no record found message.
Without using COALESCE()
select qty from X where id=1 UNION SELECT 0 order by qty desc limit 1
Demo
Related
I was able to remove the duplicate rows, but I would like to remove the duplicate rows based on one more constraint. I want to keep only a row with a smaller number of NULL values.
Original Table
Ran the SQL Server Query
WITH CTE AS(
SELECT *,
RN = ROW_NUMBER()OVER(PARTITION BY Premise_ID ORDER BY Premise_ID)
FROM sde.Premise_Test
)
DELETE FROM CTE WHERE RN > 1
Result:
But I want to get this result
I have modified the SQL script as per the comment from Aaron. but the result is still the same. DB fiddle is showing NULL from IS NULL getting highlighted.
Update the ROW_NUMBER() function like this (no, there is no shorter way):
RN = ROW_NUMBER() OVER (
PARTITION BY Premise_ID
ORDER BY Premise_ID,
CASE WHEN Division IS NULL THEN 1 ELSE 0 END
+ CASE WHEN InstallationType IS NULL THEN 1 ELSE 0 END
+ CASE WHEN OtherColumn IS NULL THEN 1 ELSE 0 END
...
)
I have a field called RecordType that has three different records, 1, 2, 3. Each hold different records. I want to take the the balance from another field I have called Limit from RecordType 1 and insert it into RecordType 3 but I'm just unsure on how to do this. This will be going into a Crystal Report and I want to be able to suppress the RecordType 1 altogether.
I've tried a simple case statement but that's about it, I can't really think of any other ways to do it (I'm sure there's loads).
CASE
WHEN FA.RecordType = 3 THEN
FA.Limit
END AS LimitTest
Current results
Record Type
Limit
1
5,000,301
2
0
3
0
Expected Results
Record Type
Limit
2
0
3
5,000,301
You seem to want to combine the limit for types 1 and 3. You can do this with aggregation on an expression:
select (case when recordtype = 1 then 3 else recordtype end) as recordtype,
sum(limit) as limit
from t
group by (case when recordtype = 1 then 3 else recordtype end);
You can try using sub-query and a Case statement in your select statement, for example:
SELECT [RecordType],
(CASE [RECORDTYPE] WHEN 3 THEN
(SELECT LIMIT from Table_1 WHERE RECORDTYPE = 1)
ELSE LIMIT END) LimitTest
FROM TABLE_1 WHERE RECORDTYPE <> 1
You said:
Sorry my formatting is terrible I'm not sure how to do it properly. But to answer your question no type 1 & 3 will never have the same value as 3 never has a value. I want to basically move the value from type 1 into type 3
Which makes me think that this would be the simplest:
DELETE FROM table WHERE RecordType = 3
UPDATE table SET RecordType = 3 WHERE RecordType = 1
3 never has a value so let's get rid of them first, then 1 has the value but we want it to be 3 so just update all the 1s to be 3s instead
If you're not into deleting it, just mask it instead:
SELECT 3 as RecordType, Limit FROM table WHERE RecordType = 1
If you want to move value from type 1 to type 3 then do simple update in your query.
update t set t.value= t1.value from table as t , table as t1 where t.recordtype=3 and t1.recordtype=1
or
delete from table where recordtype = 3
update recordtype set recordtype=1 where recordtype=3
This will work may be
SELECT
IIF(A.RECORDTYPE = 1,3,A.RECORDTYPE) AS RECORDTYPE,
A.LIMIT
FROM
(
SELECT 1 RECORDTYPE,5000301 LIMIT UNION ALL
SELECT 2 RECORDTYPE,0 LIMIT UNION ALL
SELECT 3 RECORDTYPE,0 LIMIT
) A
WHERE A.RECORDTYPE IN (1,2)
ORDER BY RECORDTYPE
Check this if works for you.
I have a result set such as:
Code No
1 *
1 -
1 4
1
1
Now i basically want a query that has 2 columns, a count for the total amount and a count for those that dont have numbers.
Code No_Number Total
1 4 5
Im assuming this needs a group by and a count but how can i do the 2 different counts in a query like this?
This is what i had so far, but i am a bit stuck with the rest of it
SELECT CODE,NO
Sum(Case when No IN ('*', '-', '') then 1 else 0 end) as Count
I think you basically just need GROUP BY:
SELECT CODE,
SUM(Case when No IN ('*', '-', '') then 1 else 0 end) as Count,
COUNT(*) as total
FROM t
GROUP BY CODE;
Well, this took a moment :-), however here it is...I have used a CASE statement to create and populate the No_Number column; the database gives the row in the original table a value of 1 if the original table value is a number or gives it a NULL and discards it from the COUNT if not. Then when it makes the count it is only recognising values which were originally numbers and ignoring everything else..
If the result set is in a table or temp table:
SELECT Code,
COUNT(CASE WHEN [No] NOT LIKE '[0-9]' THEN 1 ELSE NULL END) AS No_Number,
COUNT(Code) AS Total
FROM <tablename>
GROUP BY Code
If the result set is the product of a previous query you can use a CTE (Common Table Expression) to arrive at the required result or you could include parts of this code in the earlier query.
I have to check certain rows from table and check if-else condition for each rows
TABLE: report
COLUMNS :
sl.no, count, total_count, calls
Sample Data:
sl.no count total_count calls
----------- ----------- ----------- -----------
1 2 6 4
2 2 7 5
3 4 9 3
Here i have to check if condition
if total_count > 6
select 'Y
else
select 'N'
I get correct answer for single row. If there is multiple row it can't check all, it check only last row of my table.
Use CASE expression
SELECT
*,
CASE WHEN total_count > 6 THEN 'Yes' ELSE 'N' END
FROM report
You must use CASE.It work like if-else in t-SQL. MSDN
For example:
SELECT [num],[count], [total_count], [calls], CASE WHEN [total_count] > 6 THEN 'Y' ELSE 'N' END FROM t
You could use CASE. You can read documentation.
SELECT *,
CASE WHEN total_count > 6 THEN 'Y' ELSE ' N' END
FROM Report
The SQL version of "inline if" is CASE:
SELECT
*,
CASE WHEN total_count > 6 THEN 'Y'
ELSE 'N'
END AS IsTotalCountGreaterThanSix
FROM YourTable;
I need help with writing a select clause query.
For example, lets say I have a query like that:
select value from some_table order by value asc;
as a result I get this:
1
2
3
4
5
6
7
8
9
10
but a special query I want to write, is the one which still will give me sorted values, but will put 5 after 8.
this means I need one value to be out of regular order.
it can be described in other way. lets say I have two groups of numbers (example):
A={ a | 1<=a<=118, a!=78 } B={ b | b>118 }
I have a group C=A U B U {78}
and I need all these values sorted like "A,78,B"
Assuming value is integer, you could do this:
SELECT *
FROM tbl
ORDER BY
CASE
WHEN value = 5 THEN 8.5
ELSE value
END
Or to expand upon DCP's answer...
SELECT *
FROM tbl
ORDER BY
CASE
WHEN (Condition for first grouping) THEN 1
WHEN (Condition for second grouping) THEN 2
WHEN (Condition for third grouping) THEN 3
ELSE 4
END
You can use multiple conditions in your order by:
ORDER BY (value BETWEEN 1 AND 118) AND value != 78 DESC,
value > 118 DESC,
value
This will ensure that values which match the first predicate come first, then values matching the second predicate, and finally values matching none of the predicates. If there is a tie (two numbers matching the same predicate) then these numbers are sorted in ascending order.
Note that I haven't tested this in Oracle. It might be necessary to wrap the predicate in a CASE expression (CASE WHEN predicate THEN 1 ELSE 0 END) to get the sorting to work in Oracle.
ORDER BY
(CASE WHEN ((value BETWEEN 1 AND 118) AND value <> 78) THEN 1 ELSE 0 END) DESC,
(CASE WHEN (value > 118) THEN 1 ELSE 0 END) DESC,
value
Order by some CASE-expression to remap your values.