could you please help?
SELECT
(some columns),
SortOrder = CASE WHEN City = #inParamCity THEN 0 ELSE 1 END
FROM
dbo.addressBook
ORDER BY
SortOrder
I tried this and got:
Incorrect syntax near '=' ' –
SELECT
(some columns)
FROM
dbo.addressBook
ORDER BY
CASE
WHEN City = #inParamCity THEN 0
ELSE 1
END
Shouldn't it be like this?
SELECT (some columns),
CASE City WHEN #inParamCity THEN 0 ELSE 1 END As SortOrder
FROM dbo.addressBook
ORDER BY SortOrder
Related
Given a result set which is in the EAV structure such as :
id | attributeName | stringValue | intValue | BooleanValue
---------------------------------------------------------------
1 stringFoo v1
1 stringFooList v2
1 stringFooList v3
1 intFoo 10
1 intFooList 10
1 intFooList 20
1 booleanFoo true
1 booleanFooList true
1 booleanFooList true
How can I select all the attributes and value pair as a single value in a JSON/JSONB format , which are something likes:
{
"stringFoo" : "v1" ,
"stringFooList" : ["v2","v3"] ,
"intFoo" : 10 ,
"intFooList" : [10,20],
"booleanFoo" : true,
"booleanFooList" : [true,true]
}
If there are multiple attribute value for an attribute such as stringFooList , it will format it as JSON array.
I am using PostgreSQL 9.6
You can do something like this:
select id, jsonb_object_agg(att, value)
from (
select id,
attributename as att,
case
when count(*) > 1 then
jsonb_agg(coalesce(stringvalue,intvalue::text,booleanvalue::text))
else
to_jsonb(min(coalesce(stringvalue,intvalue::text,booleanvalue::text)))
end as value
from eav
group by id, attributename
) t
group by id;
The inner select aggregates multiple values into an JSON array, single values into JSON scalar values. And the outer query then builds a single JSON value of all rows.
Online example: https://rextester.com/TLCRN79815
#a_horse_with_no_name 's answer gives me a good start. I extend his/her answer and come up the following query such that the elements in the JSON array have the same data type of what defined in PostgreSQL.
select id, jsonb_object_agg(att,
case
when strval is not null then strval
when intvalue is not null then intvalue
else boolVal
end
)
from (
select id,
attributename as att,
case when count(*) > 1 then
jsonb_agg(stringvalue) filter (where stringvalue is not null)
else
to_jsonb(min(stringvalue) filter (where stringvalue is not null))
end as strVal,
case when count(*) > 1 then
jsonb_agg(intvalue) filter (where intvalue is not null)
else
to_jsonb(min(intvalue) filter (where intvalue is not null))
end as intvalue,
case when count(*) > 1 then
jsonb_agg(booleanvalue) filter (where booleanvalue is not null)
else
to_jsonb(bool_and(booleanvalue) filter (where booleanvalue is not null))
end as boolVal
from eav
group by id, attributename
) t
group by id;
How is it that this is valid:
ALTER PROCEDURE [StoredProcedure]
#abcID int = null -- optional param
SELECT columnJ, columnK, Count(eID) AS Num, Sum(OutXYZ) as TotalProdXYZ, Sum(RawXYZ) as TotalRawXYZ
FROM [v_ViewTable]
WHERE (#abcID IS NULL OR (abcID = #abcID))
GROUP BY columnJ, columnK
But then this is throwing a "columnJ is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause."
ALTER PROCEDURE [StoredProcedure]
#abcID int = null -- optional param
-- if 0: Group by columnJ, columnK
-- else: Group by columnK, columnJ
, #Grouping int = null
SELECT columnJ, columnK, Count(eID) AS Num, Sum(OutXYZ) as TotalProdXYZ, Sum(RawXYZ) as TotalRawXYZ
FROM [v_ViewTable]
WHERE (#abcID IS NULL OR (abcID = #abcID))
GROUP BY
CASE WHEN #Grouping = 0 THEN columnJ ELSE columnK END
,CASE WHEN #Grouping = 0 THEN columnK ELSE columnJ END
What's wrong with my CASE statement? Basically, if #Grouping = 0, I want the group by to be J, K if anything else, it should be K, J
Thanks in advance for any help!
As the message says columnJ and columnK are not contained in either an aggregate function or the GROUP BY clause in the second case. You should use field or the exact expression in select list AS IS in the GROUP BY section.
So the following statement will be ok:
SELECT CASE WHEN #Grouping = 0 THEN columnJ ELSE columnK END,
CASE WHEN #Grouping = 0 THEN columnK ELSE columnJ END,
Count(eID) AS Num, Sum(OutXYZ) as TotalProdXYZ, Sum(RawXYZ) as TotalRawXYZ
FROM [v_ViewTable]
WHERE (#abcID IS NULL OR (abcID = #abcID))
GROUP BY
CASE WHEN #Grouping = 0 THEN columnJ ELSE columnK END
,CASE WHEN #Grouping = 0 THEN columnK ELSE columnJ END
Can anyone tell me how to translate the following T-SQL statement:
SELECT fileld1 = CASE
WHEN T.option1 THEN -1
ELSE
CASE WHEN T.option2 THEN 0
ELSE 1
END
END
FROM Table1 AS T
The point is I need to validate two different options from the table for a single field in the select statement..
I have tried to do somthing with an IF statement in pl/sql, but it just doesnt work for me:
SELECT IF T.option1 THEN -1
ELSE IF T.option2 THEN 0
ELSE 1
END
FROM Table1 AS T
I am not actually sure how to write IF statement inside the SELECT statement..
And also, I need to do it INSIDE the select statement because I am constructing a view.
Use:
SELECT CASE
WHEN T.option1 = ? THEN -1
WHEN T.option2 = ? THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
I can't get your original TSQL to work - I get:
Msg 4145, Level 15, State 1, Line 4
An expression of non-boolean type specified in a context where a condition is expected, near 'THEN'.
...because there's no value evaluation. If you're checking if the columns are null, you'll need to use:
SELECT CASE
WHEN T.option1 IS NULL THEN -1
WHEN T.option2 IS NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
...or if you need when they are not null:
SELECT CASE
WHEN T.option1 IS NOT NULL THEN -1
WHEN T.option2 IS NOT NULL THEN 0
ELSE 1
END AS field1
FROM Table1 AS T
CASE expressions shortcircuit - if the first WHEN matches, it returns the value & exits handling for that row - so the options afterwards aren't considered.
If I remember correctly, PL/SQL also supports the case. You just would have to move the column alias from "field1=" before the expression to "AS filed1" after the expression.
I have a huge query which uses case/when often. Now I have this SQL here, which does not work.
(select case when xyz.something = 1
then
'SOMETEXT'
else
(select case when xyz.somethingelse = 1)
then
'SOMEOTHERTEXT'
end)
(select case when xyz.somethingelseagain = 2)
then
'SOMEOTHERTEXTGOESHERE'
end)
end) [ColumnName],
Whats causing trouble is xyz.somethingelseagain = 2, it says it could not bind that expression. xyz is some alias for a table which is joined further down in the query. Whats wrong here? Removing one of the 2 case/whens corrects that, but I need both of them, probably even more cases.
SELECT
CASE
WHEN xyz.something = 1 THEN 'SOMETEXT'
WHEN xyz.somethingelse = 1 THEN 'SOMEOTHERTEXT'
WHEN xyz.somethingelseagain = 2 THEN 'SOMEOTHERTEXTGOESHERE'
ELSE 'SOMETHING UNKNOWN'
END AS ColumnName;
As soon as a WHEN statement is true the break is implicit.
You will have to concider which WHEN Expression is the most likely to happen. If you put that WHEN at the end of a long list of WHEN statements, your sql is likely to be slower. So put it up front as the first.
More information here: break in case statement in T-SQL
declare #n int = 7,
#m int = 3;
select
case
when #n = 1 then
'SOMETEXT'
else
case
when #m = 1 then
'SOMEOTHERTEXT'
when #m = 2 then
'SOMEOTHERTEXTGOESHERE'
end
end as col1
-- n=1 => returns SOMETEXT regardless of #m
-- n=2 and m=1 => returns SOMEOTHERTEXT
-- n=2 and m=2 => returns SOMEOTHERTEXTGOESHERE
-- n=2 and m>2 => returns null (no else defined for inner case)
If logical test is against a single column then you could use something like
USE AdventureWorks2012;
GO
SELECT ProductNumber, Category =
CASE ProductLine
WHEN 'R' THEN 'Road'
WHEN 'M' THEN 'Mountain'
WHEN 'T' THEN 'Touring'
WHEN 'S' THEN 'Other sale items'
ELSE 'Not for sale'
END,
Name
FROM Production.Product
ORDER BY ProductNumber;
GO
More information - https://learn.microsoft.com/en-us/sql/t-sql/language-elements/case-transact-sql?view=sql-server-2017
OK, the umpteenth conditional column question:
I'm writing a stored proc that takes an input parameter that's mapped to one of several flag columns. What's the best way to filter on the requested column? I'm currently on SQL2000, but about to move to SQL2008, so I'll take a contemporary solution if one's available.
The table queried in the sproc looks like
ID ... fooFlag barFlag bazFlag quuxFlag
-- ------- ------- ------- --------
01 1 0 0 1
02 0 1 0 0
03 0 0 1 1
04 1 0 0 0
and I want to do something like
select ID, name, description, ...
from myTable
where (colname like #flag + 'Flag') = 1
so if I call the sproc like exec uspMyProc #flag = 'foo' I'd get back rows 1 and 4.
I know I can't do the part in parens directly in SQL. In order to do dynamic SQL, I'll have to stuff the entire query into a string, concatenate the #flag param in the WHERE clause and then exec the string. Aside from the dirty feeling I get when doing dynamic SQL, my query is fairly large (I'm selecting a couple dozen fields, joining 5 tables, calling a couple of functions), so it's a big giant string all because of a single line in a 3-line WHERE filter.
Alternately, I could have 4 copies of the query and select among them in a CASE statement. This leaves the SQL code directly executable (and subject to syntax hilighting, etc.) but at the cost of repeating big chunks of code, since I can't use the CASE on just the WHERE clause.
Are there any other options? Any tricky joins or logical operations that can be applied? Or should I just get over it and exec the dynamic SQL?
There are a few ways to do this:
You can do this with a case statement.
select ID, name, description, ...
from myTable
where CASE
WHEN #flag = 'foo' then fooFlag
WHEN #flag = 'bar' then barFlag
END = 1
You can use IF.
IF (#flag = 'foo') BEGIN
select ID, name, description, ...
from myTable
where fooFlag = 1
END ELSE IF (#flag = 'bar') BEGIN
select ID, name, description, ...
from myTable
where barFlag = 1
END
....
You can have a complicated where clause with a lot of parentheses.
select ID, name, description, ...
from myTable
where (#flag = 'foo' and fooFlag = 1)
OR (#flag = 'bar' and barFlag = 1) OR ...
You can do this with dynamic sql:
DECLARE #SQL nvarchar(4000)
SELECT #SQL = N'select ID, name, description, ...
from myTable
where (colname like ''' + #flag + 'Flag'') = 1'
EXECUTE sp_ExecuteSQL #SQL, N''
There are more, but I think one of these will get you going.
"Alternately, I could have 4 copies of the query and select among them in a CASE statement."
You don't need to copy your entire query 4 times, just add all the possibilities into the where clauses in your single copy of the query:
select ID, name, description, ...
from myTable
where (#flag = 'foo' and fooFlag = 1) OR (#flag = 'bar' and barFlag = 1) OR ...
What I would do is CASE some variables at the beginning. Example:
DECLARE
#fooFlag int,
#barFlag int,
#bazFlag int,
#quuxFlag int
SET #fooFlag = CASE WHEN #flag = 'foo' THEN 1 ELSE NULL END
SET #barFlag = CASE WHEN #flag = 'bar' THEN 1 ELSE NULL END
SET #bazFlag = CASE WHEN #flag = 'baz' THEN 1 ELSE NULL END
SET #quuxFlag = CASE WHEN #flag = 'quux' THEN 1 ELSE NULL END
SELECT ID, name, description, ...
FROM myTable
WHERE (fooFlag >= ISNULL(#fooFlag, 0) AND fooFlag <= ISNULL(#fooFlag, 1))
AND (barFlag >= ISNULL(#barFlag, 0) AND barFlag <= ISNULL(#barFlag, 1))
AND (bazFlag >= ISNULL(#bazFlag, 0) AND bazFlag <= ISNULL(#bazFlag, 1))
AND (quuxFlag >= ISNULL(#quuxFlag, 0) AND quuxFlag <= ISNULL(#quuxFlag, 1))
The good thing about this query is that, because the possible values for "flags" are bounded, you can calculate all your conditionals as prerequisites instead of wrapping columns in them. This guarantees a high-performance index seek on whichever columns are indexed, and doesn't require writing any dynamic SQL. And it's better than writing 4 separate queries for obvious reasons.
You could have a parameter for each possible flag column, then check if the parameter is null or the value in the column is equal to the parameter. Then you pass in a 1 for the flags that you want to check and leave the others null.
select id, name, description, ...
from myTable
where (#fooFlag is null or fooFlag = #fooFlag) AND
(#barFlag is null or barFlag = #barFlag) AND
...
Honestly, though, this seems like an ideal candidate for building a dynamic LINQ query and skipping the SPROC once you get to SQL2008.
int should be accepted as varchar value
declare #CompanyID as varchar(10) = '' -- or anyother value
select * from EmployeeChatTbl chat
where chat.ConversationDetails like '%'+#searchKey+'%'
and
(
(0 = CASE WHEN (#CompanyID = '' ) THEN 0 ELSE 1 END)
or
(chat.CompanyID = #CompanyID)
)
working
when the companyID is present , then filtration based on it is done, other wise , filtration is skipped.
where
case when #value<>0 then Field else 1 end
=
case when #value<>0 then #value else 1 end