I want to add condition in 'where' clause depends upon 'if' condition like below
Declare #strSQLClause varchar(50)
If (#QMasterCompanyId='09' and #State='FL' and (#LOB='HO' or #LOB='HP'))
Begin
Declare #strMonthsOccupied char(1)
select Distinct #strMonthsOccupied=sm.MonthsOccupiedDesc from HOStructureRating sr
join HOSeleMonthsOccupied sm on sr.MonthsOccupied=sm.MonthsOccupiedCd
where AppId=#AppId
If(CONVERT(int,LTRIM(RTrim(#strMonthsOccupied))) > 9)
Begin
set #strSQLClause ='AND QuestionCd!=Q8'
End
Else
set #strSQLClause =''
End
so that in my Query will work as
select * from SHSeleQuestions where MasterCompanyId='09' + #strSQLClause
But this approach is not working fine, can anyone please help me on this.
There are two ways to do this one is use dynamic sql or other one is below mention :
select *
from SHSeleQuestions
where MasterCompanyId='09' AND
1 = CASE WHEN LEN(#strSQLClause) > 0 AND QuestionCd != 'Q8' THEN 1
WHEN LEN(#strSQLClause) = 0 THEN 1 END
Using Dynamic SQL
EXEC('select * from SHSeleQuestions where MasterCompanyId=''09''' + #strSQLClause ')
You would need to use dynamic SQL, but why not just have two statements that execute SQL, so rather than set #strSQLClause = 'AND ...', simply have a select statement here with the condition(s) you need
IF (#QMasterCompanyId='09' AND #State='FL' AND (#LOB='HO' OR #LOB='HP'))
BEGIN
DECLARE #strMonthsOccupied CHAR(1)
SELECT DISTINCT #strMonthsOccupied = sm.MonthsOccupiedDesc
FROM HOStructureRating sr
INNER JOIN HOSeleMonthsOccupied sm
ON sr.MonthsOccupied=sm.MonthsOccupiedCd
WHERE AppId=#AppId;
IF(CONVERT(INT,LTRIM(RTRIM(#strMonthsOccupied))) > 9)
BEGIN
SELECT *
FROM SHSeleQuestions
WHERE MasterCompanyId='09'
AND QuestionCd!='Q8';
RETURN;
END
END
SELECT *
FROM SHSeleQuestions
WHERE MasterCompanyId='09';
That being said, there are so many issues with the above I don't really know where to begin. You declare your variable then assign it an indeterminate value:
DECLARE #strMonthsOccupied CHAR(1)
SELECT DISTINCT #strMonthsOccupied = sm.MonthsOccupiedDesc
FROM HOStructureRating sr
INNER JOIN HOSeleMonthsOccupied sm
ON sr.MonthsOccupied=sm.MonthsOccupiedCd
WHERE AppId=#AppId;
If the query returns multiple rows then there is no clear logic for which value the variable should be assigned. The nex issue is that this CHAR(1) variable is clearly a number based on your attempted conversion:
IF(CONVERT(INT,LTRIM(RTRIM(#strMonthsOccupied))) > 9)
Why not just cut out the middle man and declare an INT to begin with. The next point is that it is a CHAR(1) so isn't actually big enough to store anything greater than 9, so your above condition will never be true.
Even if sm.MonthsOccupiedDesc, was 10, the variable would simply be truncated to 1, which is smaller than 9, so fails the condition, e.g.
DECLARE #strMonthsOccupied CHAR(1) = '10';
IF(CONVERT(INT,LTRIM(RTRIM(#strMonthsOccupied))) > 9)
PRINT 'TRUE';
ELSE
PRINT 'FALSE';
Related
DECLARE #sql_string varchar(7000)
set #sql_string = (select top 1 statement from queries where name = 'report name')
EXECUTE (#sql_string)
#sql_string is holding another SQL statement. This query works for me. It returns all the values from the query from the statement on the queries table. From this, I need to figure out how to only return the results IF the number of rows returned exceeds a threshold (for my particular case, 25). Else return nothing. I can't quite figure out how to get this conditional statement to work.
Much appreciated for any direction on this.
If all the queries return the same columns, you could simply store the data in a temporary table or table variable and then use logic such as:
select t.*
from #t t
where (select count(*) from #t) > 25;
An alternative is to try constructing a new query from the existing query. I don't recommend trying to parse the existing string, if you can avoid that. Assuming that the query does not use CTEs or have an ORDER BY clause, for instance, something like this should work:
set #sql = '
with q as (
' + #sql + '
)
select q.*
from q
where (select count(*) from q) > 25
';
That did the trick #Gordon. Here was my final:
DECLARE #report_name varchar(100)
DECLARE #sql_string varchar(7000)
DECLARE #sql varchar(7000)
DECLARE #days int
set #report_name = 'Complex Pass Failed within 1 day'
set #days = 5
set #sql_string = (select top 1 statement from queries where name = #report_name )
set #sql = 'with q as (' + #sql_string + ') select q.* from q where (select count(*) from q) > ' + convert(varchar(100), #days)
EXECUTE (#sql)
Worked with 2 nuances.
The SQL returned could not include an end ";" charicter
The statement cannot include an "order by" statement
I've created a stored procedure that filters and paginates for a DataTable.
Problem: I need to set an OUTPUT variable for #TotalRecords found before an OFFSET occurs, otherwise it sets #TotalRecord to #RecordPerPage.
I've messed around with CTE's and also simply trying this:
SELECT *, #TotalRecord = COUNT(1)
FROM dbo
But that doesn't work either.
Here is my stored procedure, with most of the stuff pulled out:
ALTER PROCEDURE [dbo].[SearchErrorReports]
#FundNumber varchar(50) = null,
#ProfitSelected bit = 0,
#SortColumnName varchar(30) = null,
#SortDirection varchar(10) = null,
#StartIndex int = 0,
#RecordPerPage int = null,
#TotalRecord INT = 0 OUTPUT --NEED TO SET THIS BEFORE OFFSET!
AS
BEGIN
SET NOCOUNT ON;
SELECT *
FROM
(SELECT *
FROM dbo.View
WHERE (#ProfitSelected = 1 AND Profit = 1)) AS ERP
WHERE
((#FundNumber IS NULL OR #FundNumber = '')
OR (ERP.FundNumber LIKE '%' + #FundNumber + '%'))
ORDER BY
CASE
WHEN #SortColumnName = 'FundNumber' AND #SortDirection = 'asc'
THEN ERP.FundNumber
END ASC,
CASE
WHEN #SortColumnName = 'FundNumber' AND #SortDirection = 'desc'
THEN ERP.FundNumber
END DESC
OFFSET #StartIndex ROWS
FETCH NEXT #RecordPerPage ROWS ONLY
Thank you in advance!
You could try something like this:
create a CTE that gets the data you want to return
include a COUNT(*) OVER() in there to get the total count of rows
return just a subset (based on your OFFSET .. FETCH NEXT) from the CTE
So your code would look something along those lines:
-- CTE definition - call it whatever you like
WITH BaseData AS
(
SELECT
-- select all the relevant columns you need
p.ProductID,
p.ProductName,
-- using COUNT(*) OVER() returns the total count over all rows
TotalCount = COUNT(*) OVER()
FROM
dbo.Products p
)
-- now select from the CTE - using OFFSET/FETCH NEXT, get only those rows you
-- want - but the "TotalCount" column still contains the total count - before
-- the OFFSET/FETCH
SELECT *
FROM BaseData
ORDER BY ProductID
OFFSET 20 ROWS FETCH NEXT 15 ROWS ONLY
As a habit, I prefer non-null entries before possible null. I did not reference those in my response below, and limited a working example to just the two inputs you are most concerned with.
I believe there could be some more clean ways to apply your local variables to filter the query results without having to perform an offset. You could return to a temp table or a permanent usage table that cleans itself up and use IDs that aren't returned as a way to set pages. Smoother, with less fuss.
However, I understand that isn't always feasible, and I become frustrated myself with those attempting to solve your use case for you without attempting to answer the question. Quite often there are multiple ways to tackle any issue. Your job is to decide which one is best in your scenario. Our job is to help you figure out the script.
With that said, here's a potential solution using dynamic SQL.
I'm a huge believer in dynamic SQL, and use it extensively for user based table control and ease of ETL mapping control.
use TestCatalog;
set nocount on;
--Builds a temp table, just for test purposes
drop table if exists ##TestOffset;
create table ##TestOffset
(
Id int identity(1,1)
, RandomNumber decimal (10,7)
);
--Inserts 1000 random numbers between 0 and 100
while (select count(*) from ##TestOffset) < 1000
begin
insert into ##TestOffset
(RandomNumber)
values
(RAND()*100)
end;
set nocount off;
go
create procedure dbo.TestOffsetProc
#StartIndex int = null --I'll reference this like a page number below
, #RecordsPerPage int = null
as
begin
declare #MaxRows int = 30; --your front end will probably manage this, but don't trust it. I personally would store this on a table against each display so it can also be returned dynamically with less manual intrusion to this procedure.
declare #FirstRow int;
--Quick entry to ensure your record count returned doesn't excede max allowed.
if #RecordsPerPage is null or #RecordsPerPage > #MaxRows
begin
set #RecordsPerPage = #MaxRows
end;
--Same here, making sure not to return NULL to your dynamic statement. If null is returned from any variable, the entire statement will become null.
if #StartIndex is null
begin
set #StartIndex = 0
end;
set #FirstRow = #StartIndex * #RecordsPerPage
declare #Sql nvarchar(2000) = 'select
tos.*
from ##TestOffset as tos
order by tos.RandomNumber desc
offset ' + convert(nvarchar,#FirstRow) + ' rows
fetch next ' + convert(nvarchar,#RecordsPerPage) + ' rows only'
exec (#Sql);
end
go
exec dbo.TestOffsetProc;
drop table ##TestOffset;
drop procedure dbo.TestOffsetProc;
I have 2 stored procedures which return the same columns that I am trying to merge into a single procedure. They both have a different set of parameters and both have different WHERE clauses, but they use the same tables and select the exact same rows.
WHERE clause 1: (uses #UIOID, and #Level)
WHERE ( #UIOID = CASE WHEN #Level = 'Single' THEN C.C_UIOID_PK
WHEN #Level = 'Children' THEN CLC.UIOL_P
WHEN #Level = 'Parent' THEN CLP.UIOL_C
END
OR ( #UIOID = '0'
AND #Level = 'All'
)
)
Where clause 2: (Uses #TeamCode, #Year, #IncludeQCodes)
WHERE C.C_IsChild = 0
AND C.C_MOA <> 'ADD'
AND #TeamCode = C.C_OffOrg
AND C.C_Active = 'Y'
AND ( #Year BETWEEN dbo.f_GetAcYearByDate(C.C_StartDate) AND dbo.f_GetAcYearByDate(C.C_EndDate)
OR #Year = 0 )
AND ( C.C_InstCode NOT LIKE 'Q%'
OR #IncludeQCodes = 1 )
Ideally I want to add a new parameter which basically tells it which of the two WHERE clauses to run, but I can't seem to recreate that with CASE statement because as far as I can tell, they only work for a single WHERE clause, not a whole set of different clauses
I want to do this without having to repeat the select statement again and putting the whole thing in IF statements, and i don't want to put the query into a string either. I just want one select statement ideally.
The problem with using temp tables is the query itself takes a while to run without any parameters and is used in a live website, so I don't want it to have to put all records in a temp table and then filter it.
The problem with using a CTE is you can't follow it with an IF statement, so that wouldn't work either.
Here is the sort of logic I am trying to achieve:
SELECT A
B
C
FROM X
IF #WhichOption = 1 THEN
WHERE ( #UIOID = CASE WHEN #Level = 'Single' THEN C.C_UIOID_PK
WHEN #Level = 'Children' THEN CLC.UIOL_P
WHEN #Level = 'Parent' THEN CLP.UIOL_C
END
OR ( #UIOID = '0'
AND #Level = 'All'
)
)
ELSE IF #WhichOption = 2 THEN
WHERE C.C_IsChild = 0
AND C.C_MOA <> 'ADD'
AND #TeamCode = C.C_OffOrg
AND C.C_Active = 'Y'
AND ( #Year BETWEEN dbo.f_GetAcYearByDate(C.C_StartDate) AND dbo.f_GetAcYearByDate(C.C_EndDate)
OR #Year = 0 )
AND ( C.C_InstCode NOT LIKE 'Q%'
OR #IncludeQCodes = 1 )
Save the following process in a procedure. You can also directly insert into a physical table.
declare #varTable Table (columns exactly as Procedures return)
if(condition is met)
begin
insert into #varTable
exec proc1
end
else
begin
insert into #varTable
exec proc2
end
Add the parameter that you said that it would indicate what filter apply :
select XXXXX
from XXXXX
where (#Mode = 1 and ( filter 1 ))
or
(#Mode = 2 and ( filter 2 ))
option(recompile)
If the #Mode parameter is 1 then it will evaluate the filter 1, otherwise it will evaluate the filter 2.
Add an option(recompile) at the end of the statement, so the SQL engine will replace the variables with their values, eliminate the filter that won't be evaluated, and generate an execution plant for just the filter that you want to apply.
PS: Please notice that although these catchall queries are very easy to code and maintain, and generate a perfectly functional and optimal execution, they are not advised for high-demand applications. The option(recompile) forces the engine to recompile and generate a new execution plan at every execution and that would have a noticeable effect on performance if your query needs to be executed hundreds of times per minute. But for the occasional use it's perfectly fine.
Try to use dynamic SQL:
DECLARE #sql NVARCHAR(max), #where NVARCHAR(max), #WhichOption INT = 1;
SET #sql = 'SELECT A
B
C
FROM X';
IF #WhichOption = 1
SET #where = 'WHERE ( #UIOID = CASE WHEN #Level = ''Single'' THEN C.C_UIOID_PK
WHEN #Level = ''Children'' THEN CLC.UIOL_P
WHEN #Level = ''Parent'' THEN CLP.UIOL_C
END
OR ( #UIOID = ''0''
AND #Level = ''All''
)
)';
ELSE IF #WhichOption = 2
SET #where = ' WHERE C.C_IsChild = 0
AND C.C_MOA <> ''ADD''
AND #TeamCode = C.C_OffOrg
AND C.C_Active = ''Y''
AND ( #Year BETWEEN dbo.f_GetAcYearByDate(C.C_StartDate)
AND dbo.f_GetAcYearByDate(C.C_EndDate)
OR #Year = 0 )
AND ( C.C_InstCode NOT LIKE ''Q%''
OR #IncludeQCodes = 1 ) ';
SET #sql = CONCAT(#sql,' ', #where)
PRINT #sql
EXECUTE sp_executesql #sql
How can i find the occurrences of 'e' at then end only of a string in sql?
For example:
abcdeee, occurrences: 3
aecdeae, occurrences: 1
Thanks.
The goal is going to be to avoid looping if at all possible, since SQL Server works much better with sets of data rather than processing things sequentially. With that in mind, I would generate a virtual table that gives you all of the counts that you might find. To be safe, it should be the same length as your column. In my example, I've stopped at 10 characters. I use a CTE to generate the virtual table. You can use a variable in there instead of the hard-coded 'e' of course. Also, the CAST()s are important to avoid data type mismatches with the recursive CTE, but you may need to adjust them, especially if you're using NVARCHAR.
;WITH CTE_Characters AS
(
SELECT
CAST('e' AS VARCHAR(10)) AS my_char, 1 AS cnt
UNION ALL
SELECT
CAST(my_char + 'e' AS VARCHAR(10)), cnt + 1
FROM
CTE_Characters
WHERE
cnt <= 9
)
SELECT
MT.my_string,
MAX(CTE.cnt) AS number_of_occurrences
FROM
My_Table MT
INNER JOIN CTE_Characters CTE ON REVERSE(MT.my_string) LIKE CTE.my_char + '%'
GROUP BY
MT.my_string
Here is a loop that will count the instances of 'e' on the end of an incoming string:
DECLARE #str nvarchar(50) = 'abcdeee'; --incoming string
DECLARE #ctr int = 0; --to count instances
DECLARE #rts nvarchar(50) = REVERSE(#str); --reverse the incoming string to start from the end
DECLARE #ind int = CHARINDEX('e',#rts,1); --find the first instance of e
WHILE #ind = 1 --only continue to count consecutive instances
BEGIN
SET #ctr += 1;
SET #rts = RIGHT(#rts,LEN(#rts)-1); --remove first character and re-run
SET #ind = CHARINDEX('e',#rts,1); --find next e
END
SELECT #ctr AS ctr
I've heard that in some programming languages it is faster to check if the length of a string is 0, than to check if the content is "". Is this also true for T-SQL?
Sample:
SELECT user_id FROM users WHERE LEN(user_email) = 0
vs.
SELECT user_id FROM users WHERE user_email = ''
Edit
You've updated your question since I first looked at it. In that example I would say that you should definitely always use
SELECT user_id FROM users WHERE user_email = ''
Not
SELECT user_id FROM users WHERE LEN(user_email) = 0
The first one will allow an index to be used. As a performance optimisation this will trump some string micro optimisation every time! To see this
SELECT * into #temp FROM [master].[dbo].[spt_values]
CREATE CLUSTERED INDEX ix ON #temp([name],[number])
SELECT [number] FROM #temp WHERE [name] = ''
SELECT [number] FROM #temp WHERE LEN([name]) = 0
Execution Plans
Original Answer
In the code below (SQL Server 2008 - I "borrowed" the timing framework from #8kb's answer here) I got a slight edge for testing the length rather than the contents below when #stringToTest contained a string. They were equal timings when NULL. I probably didn't test enough to draw any firm conclusions though.
In a typical execution plan I would imagine the difference would be negligible and if you're doing that much string comparison in TSQL that it will be likely to make any significant difference you should probably be using a different language for it.
DECLARE #date DATETIME2
DECLARE #testContents INT
DECLARE #testLength INT
SET #testContents = 0
SET #testLength = 0
DECLARE
#count INT,
#value INT,
#stringToTest varchar(100)
set #stringToTest = 'jasdsdjkfhjskdhdfkjshdfkjsdehdjfk'
SET #count = 1
WHILE #count < 10000000
BEGIN
SET #date = GETDATE()
SELECT #value = CASE WHEN #stringToTest = '' then 1 else 0 end
SET #testContents = #testContents + DATEDIFF(MICROSECOND, #date, GETDATE())
SET #date = GETDATE()
SELECT #value = CASE WHEN len(#stringToTest) = 0 then 1 else 0 end
SET #testLength = #testLength + DATEDIFF(MICROSECOND, #date, GETDATE())
SET #count = #count + 1
END
SELECT
#testContents / 1000000. AS Seconds_TestingContents,
#testLength / 1000000. AS Seconds_TestingLength
I would be careful about using LEN in a WHERE clause as it could lead to table or index scans.
Also note that if the field is NULLable that LEN(NULL) = NULL, so you would need to define the behaviour, e.g.:
-- Cost .33
select * from [table]
where itemid = ''
-- Cost .53
select * from [table]
where len(itemid) = 0
-- `NULL`able source field (and assuming we treat NULL and '' as the same)
select * from [table]
where len(itemid) = 0 or itemid is NULL
I just tested it in a very limited scenario and execution plan ever so slightly favours comparing it to an empty string. (49% to 51%). This is working with stuff in memory though so it would probably be different if comparing against data from a table.
DECLARE #testString nvarchar(max)
SET #testString = ''
SELECT
1
WHERE
#testString = ''
SELECT
1
WHERE
LEN(#testString) = 0
Edit: This is with SQL Server 2005.
I suspect the answer depends largely on the context. For example, I have been working with expressions in the SELECT list and in user-defined functions. Knowing what I do about the Microsoft .NET Base Class Library and the legacy that Transact-SQL owes to Visual Basic, I suspect that in such circumstances, LEN ( string ) gets the nod.