I am having problems returning a VARCHAR out of a derived column.
Below are extremely simplified code examples.
I have been able to do this before:
SELECT *, message =
CASE
WHEN (status = 0)
THEN 'aaa'
END
FROM products
But when I introduce a Common Table Expression or Derived Table:
WITH CTE_products AS (SELECT * from products)
SELECT *, message =
CASE WHEN (status = 0)
THEN 'aaa'
END
FROM CTE_products
this seems to fail with the following message:
Conversion failed when converting the varchar value 'aaa' to data type int.
When I tweak the line to say:
WITH CTE_products AS (SELECT * from products)
SELECT *, message =
CASE WHEN (status = 0)
THEN '123'
END
FROM CTE_products
It returns correctly.
...
When I remove all the other clauses prior to it, it also works fine returning 'aaa'.
My preference would be to keep this as a single, stand-alone query.
The problem is that the column is an integer dataype and sql server is trying to convert 'aaa' to integer
one way
WITH CTE_products AS (SELECT * from products)
SELECT *, message =
CASE WHEN (status = 0)
THEN 'aaa' else convert(varchar(50),status)
END
FROM CTE_products
I actually ended up finding the answer.
One of my CASE/WHEN clauses used a derived column from the CTE and that ended up causing the confusion.
Before:
WITH CTE_products AS (SELECT *, qty_a + qty_b as qty_total FROM products)
SELECT *, message =
CASE WHEN (status = 0)
THEN 'Status is 0, the total is: ' + qty_total + '!'
END
FROM CTE_products
Corrected:
WITH CTE_products AS (SELECT *, qty_a + qty_b as qty_total FROM products)
SELECT *, message =
CASE WHEN (status = 0)
THEN 'Status is 0, the total is: ' + CAST(qty_total AS VARCHAR) + '!'
END
FROM CTE_products
I ended up removing WHEN/THEN clauses within the CASE statement right afterwards to see if it was a flukey parentheses error when I realized that in the absence of any of the WHEN/THEN clauses that included the derived column from the CTE, it was able to return VARCHAR.
Related
I am working on migrating data from one database to another for a hospital. In the old database, the doctor's specialty IDs are all in one column (swvar_specialties), each separated by commas. In the new database, each specialty ID will have it's own column (example: Specialty1_PrimaryID, Specialty2_PrimaryID, Specialty3_PrimaryID, etc). I am trying to export the data out of the old database and separate these into these separate columns. I know I can use indexof and substring to do this - I just need help with the syntax.
So this query:
Select swvar_specialties as Specialty1_PrimaryID
From PhysDirectory
might return results similar to 39,52,16. I need this query to display Specialty1_PrimaryID = 39, Specialty2_PrimaryID = 52, and Specialty3_PrimaryID = 16 in the results. Below is my query so far. I will eventually have a join to pull the specialty names from the specialties table. I just need to get this worked out first.
Select pd.ref as PrimaryID, pd.swvar_name_first as FirstName, pd.swvar_name_middle as MiddleName,
pd.swvar_name_last as LastName, pd.swvar_name_suffix + ' ' + pd.swvar_name_degree as NameSuffix,
pd.swvar_birthdate as DateOfBirth,pd.swvar_notes as AdditionalInformation, 'images/' + '' + pd.swvar_photo as ImageURL,
pd.swvar_philosophy as PhilosophyOfCare, pd.swvar_gender as Gender, pd.swvar_specialties as Specialty1_PrimaryID, pd.swvar_languages as Language1_Name
From PhysDirectory as pd
The article Split function equivalent in T-SQL? provides some details on how to use a split function to split a comma-delimited string.
By modifying the table-valued function in presented in this article to provide an identity column we can target a specific row such as Specialty1_PrimaryID:
/*
Splits string into parts delimitered with specified character.
*/
CREATE FUNCTION [dbo].[SDF_SplitString]
(
#sString nvarchar(2048),
#cDelimiter nchar(1)
)
RETURNS #tParts TABLE (id bigint IDENTITY, part nvarchar(2048) )
AS
BEGIN
if #sString is null return
declare #iStart int,
#iPos int
if substring( #sString, 1, 1 ) = #cDelimiter
begin
set #iStart = 2
insert into #tParts
values( null )
end
else
set #iStart = 1
while 1=1
begin
set #iPos = charindex( #cDelimiter, #sString, #iStart )
if #iPos = 0
set #iPos = len( #sString )+1
if #iPos - #iStart > 0
insert into #tParts
values ( substring( #sString, #iStart, #iPos-#iStart ))
else
insert into #tParts
values( null )
set #iStart = #iPos+1
if #iStart > len( #sString )
break
end
RETURN
END
Your query can the utilise this split function as follows:
Select
pd.ref as PrimaryID,
pd.swvar_name_first as FirstName,
pd.swvar_name_middle as MiddleName,
pd.swvar_name_last as LastName,
pd.swvar_name_suffix + ' ' + pd.swvar_name_degree as LastName,
pd.swvar_birthdate as DateOfBirth,pd.swvar_notes as AdditionalInformation,
'images/' + '' + pd.swvar_photo as ImageURL,
pd.swvar_philosophy as PhilosophyOfCare, pd.swvar_gender as Gender,
(Select part from SDF_SplitString(pd.swvar_specialties, ',') where id=1) as Specialty1_PrimaryID,
(Select part from SDF_SplitString(pd.swvar_specialties, ',') where id=2) as Specialty2_PrimaryID,
pd.swvar_languages as Language1_Name
From PhysDirectory as pd
I am developing a TSQL stored proc using SSMS 2008 and am receiving the above error while generating a CTE. I want to add logic to this SP to return every day, not just the days with data. How do I do this? Here is my SP so far:
ALTER Proc [dbo].[rpt_rd_CensusWithChart]
#program uniqueidentifier = NULL,
#office uniqueidentifier = NULL
AS
DECLARE #a_date datetime
SET #a_date = case when MONTH(GETDATE()) >= 7 THEN '7/1/' + CAST(YEAR(GETDATE()) AS VARCHAR(30))
ELSE '7/1/' + CAST(YEAR(GETDATE())-1 AS VARCHAR(30)) END
if exists (
select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#ENROLLEES')
) DROP TABLE #ENROLLEES;
if exists (
select * from tempdb.dbo.sysobjects o where o.xtype in ('U') and o.id = object_id(N'tempdb..#DISCHARGES')
) DROP TABLE #DISCHARGES;
declare #sum_enrollment int
set #sum_enrollment =
(select sum(1)
from enrollment_view A
join enrollment_info_expanded_view C on A.enrollment_id = C.enroll_el_id
where
(#office is NULL OR A.group_profile_id = #office)
AND (#program is NULL OR A.program_info_id = #program)
and (C.pe_end_date IS NULL OR C.pe_end_date > #a_date)
AND C.pe_start_date IS NOT NULL and C.pe_start_date < #a_date)
select
A.program_info_id as [Program code],
A.[program_name],
A.profile_name as Facility,
A.group_profile_id as Facility_code,
A.people_id,
1 as enrollment_id,
C.pe_start_date,
C.pe_end_date,
LEFT(datename(month,(C.pe_start_date)),3) as a_month,
day(C.pe_start_date) as a_day,
#sum_enrollment as sum_enrollment
into #ENROLLEES
from enrollment_view A
join enrollment_info_expanded_view C on A.enrollment_id = C.enroll_el_id
where
(#office is NULL OR A.group_profile_id = #office)
AND (#program is NULL OR A.program_info_id = #program)
and (C.pe_end_date IS NULL OR C.pe_end_date > #a_date)
AND C.pe_start_date IS NOT NULL and C.pe_start_date >= #a_date
;WITH #ENROLLEES AS (
SELECT '7/1/11' AS dt
UNION ALL
SELECT DATEADD(d, 1, pe_start_date) as dt
FROM #ENROLLEES s
WHERE DATEADD(d, 1, pe_start_date) <= '12/1/11')
The most obvious issue (and probably the one that causes the error message too) is the absence of the actual statement to which the last CTE is supposed to pertain. I presume it should be a SELECT statement, one that would combine the result set of the CTE with the data from the #ENROLLEES table.
And that's where another issue emerges.
You see, apart from the fact that a name that starts with a single # is hardly advisable for anything that is not a local temporary table (a CTE is not a table indeed), you've also chosen for your CTE a particular name that already belongs to an existing table (more precisely, to the already mentioned #ENROLLEES temporary table), and the one you are going to pull data from too. You should definitely not use an existing table's name for a CTE, or you will not be able to join it with the CTE due to the name conflict.
It also appears that, based on its code, the last CTE represents an unfinished implementation of the logic you say you want to add to the SP. I can suggest some idea, but before I go on I'd like you to realise that there are actually two different requests in your post. One is about finding the cause of the error message, the other is about code for a new logic. Generally you are probably better off separating such requests into distinct questions, and so you might be in this case as well.
Anyway, here's my suggestion:
build a complete list of dates you want to be accounted for in the result set (that's what the CTE will be used for);
left-join that list with the #ENROLLEES table to pick data for the existing dates and some defaults or NULLs for the non-existing ones.
It might be implemented like this:
… /* all your code up until the last WITH */
;
WITH cte AS (
SELECT CAST('7/1/11' AS date) AS dt
UNION ALL
SELECT DATEADD(d, 1, dt) as dt
FROM cte
WHERE dt < '12/1/11'
)
SELECT
cte.dt,
tmp.[Program code],
tmp.[program_name],
… /* other columns as necessary; you might also consider
enveloping some or all of the "tmp" columns in ISNULLs,
like in
ISNULL(tmp.[Program code], '(none)') AS [Program code]
to provide default values for absent data */
FROM cte
LEFT JOIN #ENROLLEES tmp ON cte.dt = tmp.pe_start_date
;
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
I have the following SP
CREATE PROCEDURE GetAllHouses
set #webRegionID = 2
set #sortBy = 'case_no'
set #sortDirection = 'ASC'
AS
BEGIN
Select
tbl_houses.*
from tbl_houses
where
postal in (select zipcode from crm_zipcodes where web_region_id = #webRegionID)
ORDER BY
CASE UPPER(#sortBy)
when 'CASE_NO' then case_no
when 'AREA' then area
when 'FURNISHED' then furnished
when 'TYPE' then [type]
when 'SQUAREFEETS' then squarefeets
when 'BEDROOMS' then bedrooms
when 'LIVINGROOMS' then livingrooms
when 'BATHROOMS' then bathrooms
when 'LEASE_FROM' then lease_from
when 'RENT' then rent
else case_no
END
END
GO
Now everything in that SP works but I want to be able to choose whether I want to sort ASCENDING or DESCENDING.
I really can't fint no solution for that using SQL and can't find anything in google.
As you can see I have the parameter sortDirection and I have tried using it in multiple ways but always with errors... Tried Case Statements, IF statements and so on but it is complicated by the fact that I want to insert a keyword.
Help will be very much appriciated, I have tried must of the things that comes into mind but haven't been able to get it right.
You could use two order by fields:
CASE #sortDir WHEN 'ASC' THEN
CASE UPPER(#sortBy)
...
END
END ASC,
CASE #sortDir WHEN 'DESC' THEN
CASE UPPER(#sortBy)
...
END
END DESC
A CASE will evaluate as NULL if none of the WHEN clauses match, so that causes one of the two fields to evaluate to NULL for every row (not affecting the sort order) and the other has the appropriate direction.
One drawback, though, is that you'd need to duplicate your #sortBy CASE statement. You could achieve the same thing using dynamic SQL with sp_executesql and writing a 'ASC' or 'DESC' literal depending on the parameter.
That code is going to get very unmanageable very quickly as you'll need to double nest your CASE WHEN's... one set for the Column to order by, and nested set for whethers it's ASC or DESC
Might be better to consider using Dynamic SQL here...
DECLARE #sql nvarchar(max)
SET #sql = '
Select
tbl_houses.*
from tbl_houses
where
postal in (select zipcode from crm_zipcodes where web_region_id = ' + #webRegionID + ') ORDER BY '
SET #sql = #sql + ' ' + #sortBy + ' ' + #sortDirection
EXEC (#sql)
You could do it with some dynamic SQL and calling it with an EXEC. Beware SQL injection though if the user has any control over the parameters.
CREATE PROCEDURE GetAllHouses
set #webRegionID = 2
set #sortBy = 'case_no'
set #sortDirection = 'ASC'
AS
BEGIN
DECLARE #dynamicSQL NVARCHAR(MAX)
SET #dynamicSQL =
'
SELECT
tbl_houses.*
FROM
tbl_houses
WHERE
postal
IN
(
SELECT
zipcode
FROM
crm_zipcodes
WHERE
web_region_id = ' + CONVERT(nvarchar(10), #webRegionID) + '
)
ORDER BY
' + #sortBy + ' ' + #sortDirection
EXEC(#dynamicSQL)
END
GO