Conditional operator in Transact-sql - sql

Is there a way to do this shorter, for instance using some sort of conditional operator in Transact-sql?
IF #ParentBinaryAssetStructureId = -1
BEGIN
SET #ParentBinaryAssetStructureId = NULL
END
UPDATE BinaryAssets.BinaryAssetStructures
SET ParentBinaryAssetStructureId = #ParentBinaryAssetStructureId
WHERE BinaryAssetStructureId = #OriginalBinaryAssetStructureId


USE NULLIF()
UPDATE BinaryAssets.BinaryAssetStructures
SET ParentBinaryAssetStructureId = NULLIF(#ParentBinaryAssetStructureId,-1)
WHERE BinaryAssetStructureId = #OriginalBinaryAssetStructureId


The ternary (conditional) operator in c like languages:
x = doSomething ? 5 : 7
would be written like this in SQL:
SELECT #x = CASE WHEN #doSomething = 1 THEN 5 ELSE 0 END
There can be multiple cases (when clauses):
SELECT #x = CASE WHEN #doSomething = 1 THEN 5 WHEN #somethingElse = 1 THEN 20 ELSE 0 END


UPDATE BinaryAssets.BinaryAssetStructures
SET ParentBinaryAssetStructureId =
CASE ParentBinaryAssetStructureId
WHEN -1 THEN NULL
ELSE ParentBinaryAssetStructureId
END
WHERE BinaryAssetStructureId = #OriginalBinaryAssetStructureId
Give that a whirl

Related

SQL - WHERE with CASE statement

SELECT TOP 1
CostValue
FROM
[~client_table~].[dbo].[CostRules] AS CostRule
WHERE
(CASE
WHEN DATALENGTH(CostRule.ModelName) = 0
THEN
CostRule.Type = 1
AND CostRule.Manufacturer = Printer.ManufacturerId
AND CostRule.ColorType = 1
ELSE
CostRule.Type = 2
AND CostRule.ModelName = Printer.ModelName
AND CostRule.ColorType = 1
END
)
) AS MonoCost
I want to define my where statement depending on the datalength of CostRule.ModelName. But i got an error: Incorrect syntax near '='. in CostRule.Type = 1 and i got a error in the ELSE statement.

Must be like this:
...
WHERE
(DATALENGTH(CostRule.ModelName) = 0
AND CostRule.Type = 1
AND CostRule.Manufacturer = Printer.ManufacturerId
AND CostRule.ColorType = 1)
OR
(DATALENGTH(CostRule.ModelName) != 0
AND CostRule.Type = 2
AND CostRule.ModelName = Printer.ModelName
AND CostRule.ColorType = 1)
The CASE-style from your query cannot work.

you can change your statement like this:
SELECT TOP 1
CostValue
FROM
[~client_table~].[dbo].[CostRules] AS CostRule
WHERE CostRule.ColorType=1
AND CostRule.Type=CASE WHEN DATALENGTH(CostRule.ModelName) = 0 THEN 1 ELSE 2 END
AND CostRule.Manufacturer=CASE WHEN DATALENGTH(CostRule.ModelName) = 0 THEN Printer.ManufacturerId ELSE Printer.ModelName END

You can't use a CASE statement to define where conditions like that. It will be easier to just use some boolean logic
SELECT *
FROM your_table
WHERE (DATALENGTH(CostRule.ModelName) = 0
AND CostRule.Type = 1
AND CostRule.Manufacturer = Printer.ManufacturerId
AND CostRule.ColorType = 1)
OR (DATALENGTH(CostRule.ModelName) != 0
AND CostRule.Type = 2
AND CostRule.ModelName = Printer.ModelName
AND CostRule.ColorType = 1)
There are some other things that could be removed (like CostRule.ColorType = 1 since it is the same in both branches) but I've left them in here to illustrate how to transform your CASE statement into a boolean logic set.

It looks like you would just need to change the WHERE statement:
It looks like you will just need to change your WHERE statement to use OR and remove the CASE Statement.
(SELECT TOP 1
CostValue
FROM
[~client_table~].[dbo].[CostRules] AS CostRule
WHERE
DATALENGTH(CostRule.ModelName) = 0
CostRule.Type = 1
AND CostRule.Manufacturer = Printer.ManufacturerId
AND CostRule.ColorType = 1
OR
DATALENGTH(CostRule.ModelName) <> 0
AND CostRule.Type = 2
AND CostRule.ModelName = Printer.ModelName
AND CostRule.ColorType = 1
) AS MonoCost

Rewrite subquery with calculation in SQL to CASE statement

I have, as a part of a bigger query, some subqueries that I would like to convert to CASE statements instead.
The subquery looks like this (and works):
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM [F0001].[dbo].[ProdTr] WHERE AcYrPr = '201601' AND ProdTr.TrTp = 1 AND [F0001].[dbo].[ProdTr].CustNo = '12773') AS dg_period_1
However, I don't seem to find any logical way to put this into a CASE-statement.
Any help would be appreciated!

(
SELECT CASE
WHEN SUM(t1.DAm) <> 0
THEN (SUM(t1.DAm) + SUM(t1.StcCst)) * 100 / SUM(t1.DAm)
ELSE 0 /* or whatever you want to have in this case */
END AS 'DG'
FROM [F0001].[dbo].[ProdTr] t1
WHERE t1.AcYrPr = '201601' AND
t1.TrTp = 1 AND
t1.CustNo = '12773'
) AS dg_period_1
I also removed some unneeded parentheses and simplified an operation (x - (y * -1) = x + y)

You could use the following statement with CASE provided you want to return a null when SUM(DAm) is null or 0.
(SELECT CASE
WHEN SUM(DAm) IS NOT NULL and SUM(DAm) <> 0 THEN (((SUM(DAm) - (SUM(StcCst) * -1)) * 100) /SUM(DAm))
ELSE NULL
END AS 'DG'
FROM [F0001].[dbo].[ProdTr]
WHERE AcYrPr = '201601'
AND ProdTr.TrTp = 1
AND [F0001].[dbo].[ProdTr].CustNo = '12773') AS dg_period_1

Is there a way to ignore the AND in a CASE when something is true?

I have this Where clause
Select * From Student_Info si
Inner Join Certifications cc
Inner Join Cert_Earned ce
Where si.grad_date = #grad_date
AND cc.org_no = #org_no
but I need an additional AND that should be ignored if it turns out the value is false, I will want ALL certificates
AND cc.industrial = CASE WHEN #industrial = 0 THEN Do Nothing
Else #industrial

This would normally be expressed as:
AND (#industrial = 0 OR ccc.industrial = #industrial)

It sounds like you just want to add a predicate that does an OR between two different conditions
AND (#industrial = 0 or ccc.industrial = #industrial)

You can do something like this with CASE functions:
AND 1 = (CASE WHEN #industrial = 0 THEN 1
ELSE CASE WHEN cc.industrial = #industrial THEN 1 END
END)
or if cc.industrial is not nullable, then maybe:
AND cc.industrial = CASE WHEN #industrial = 0 THEN cc.industrial
Else #industrial END

Combining Case Statements in a View

I have these two case statements and can not for the life of me figure out how to combine them to show in a MSSQL view. Any help would be great.
CASE WHEN [ordertype] = '2' THEN [CommissionAmt1] * - 1 ELSE [CommissionAmt1] END
and
CASE WHEN (is_member('Buyer') = 1 OR is_member('CustomerService') = 1) THEN 0 ELSE CommissionAmt1 END

Just adding the first case to wherever the CommissionAmt1 is referenced in the second statement.
CASE WHEN (is_member('Buyer') = 1 OR is_member('CustomerService') = 1) THEN
0
ELSE
CASE WHEN [ordertype] = '2' THEN
[CommissionAmt1] * - 1
ELSE
[CommissionAmt1]
END
END
Or going the other way. It was hard to understand which way the calculation needs to be performed. The only hint was []
CASE WHEN [ordertype] = '2' THEN
(
CASE WHEN (is_member('Buyer') = 1 OR is_member('CustomerService') = 1) THEN
0
ELSE
CommissionAmt1
END
) * - 1
ELSE
CASE WHEN (is_member('Buyer') = 1 OR is_member('CustomerService') = 1) THEN
0
ELSE
CommissionAmt1
END
END
Either way, you would be able to save some calculations by sub querying the dependent value.
SELECT
*,
ValueWithDependant=CASE WHEN (Dependant>0) THEN (SomeValue / Dependant) ELSE NULL END
FROM
(
SELECT
X,Y,Z,
Dependant=CASE WHEN SomeValue=1 THEN 1 ELSE 0 END
FROM
SomeTable
)AS DETAIL

SQL Server : IF Condition in WHERE clause

I have a bit parameter
#IsInRetry
If it is false I have to set the where condition to
attempts = 0
else if it is true I have to set the where condition to
attempts > 0
How could this be done?

Try this way:
( (#IsInRetry = 0 and attempts = 0) or (#IsInRetry = 1 and attempts > 0) )

Try this:
WHERE (attempts = #IsInRetry or (#IsInRetry = 1 and attempts > 0))

Try this, should work also for negative attempts :-)
#IsInRetry = (attempts > 0)
Greetings.

This:
if #IsInRetry = 0x0
BEGIN
SELECT * FROM dbo.tbl
WHERE attempts = 0
END
ELSE
BEGIN
SELECT * FROM dbo.tbl
WHERE attempts = 1
END