In the OR section of a WHERE clause I have something like this:
COALESCE(Table2.FireDate, Table1.HireDate,'06/06/2079') = ISNULL(Table3.DeathDate,'06/06/2079')
I wanted to see is there a way to avoid COALESCE call and still achieve the same result? My hope is gaining some performance if possible.
I don't sure that performance will be better. But you can get rid from coalesce as you want:
declare #fireDate date = null -- '01/20/2017'
declare #hireDate date = '01/20/2017'
declare #deathDate date = '01/20/2017'
if (COALESCE(#fireDate, #hireDate, '06/06/2079') = ISNULL(#deathDate, '06/06/2079'))
begin
select '+'
end;
if(#fireDate is null and #hireDate is null and #deathDate is null)
or (#fireDate = #deathDate)
or (#fireDate is null and #hireDate = #deathDate) begin
select '+'
end;
Related
Have two variable StatusTypeTestID and StatusTestID want to set them as optional in where clause as like bellow,but optional option not work for int variable.
Note: default value for int variable is 0
DECLARE #StatusTypeTestID as int
SET #StatusTypeTestID = 1
DECLARE #StatusTestID as int
SET #StatusTestID = 0
select *
from LiveCustomerStatus
where (StatusType=#StatusTypeTestID
and (Status = #StatusTestID or #StatusTestID is null))
As you were already trying, you can check if your parameters have been set as null or if they match the correspondent field.
This way you can leave a parameter as null if you want it to be optional, not affecting the result.
select *
from LiveCustomerStatus
where (#StatusTypeTestID is null or StatusType=#StatusTypeTestID)
and (#StatusTestID is null or Status = #StatusTestID)
option(recompile)
I have added a option(recompile) clause that will force SQL Server to recompile the query at every execution. This way it will use the appropriate indexes to optimize it depending of the value of the parameters (wether they are null or not).
You can comment both set statements and below query will work:
select * from LiveCustomerStatus
where (#StatusTypeTestID is null or StatusType=#StatusTypeTestID)
and (#StatusTestID is null or Status = #StatusTestID)
Use CASE Statement in WHERE clause :
SELECT *
FROM LiveCustomerStatus
WHERE StatusType = CASE WHEN ISNULL(#StatusTypeTestID,'') = '' THEN
StatusType ELSE #StatusTypeTestID END
AND Status = CASE WHEN ISNULL(#StatusTestID,'')= '' THEN Status ELSE
#StatusTestID END
I'm trying to compare if my variable datetime is NULL, but it doesn't work, I'm new making comparising in SQL, so could someone said me how is the good way. This is my code:
declare #FechaInicial datetime
set #FechaInicial = (select FecharIncialDescarga
from Contenedores where Id_Contenedor=#IdContenedor)
if(#FechaInicial = NULL) ---
begin
end
The direct answer to your question is is null:
if (#FechaInicial IS NULL)
This is because almost any comparison to NULL returns NULL, and NULL is treated as false.
However, I want to point out that you might really intend this logic:
if (not exists (select 1 from Contenedores where Id_Contenedor = #IdContenedor))
begin
. . .
end;
Although there is nothing wrong with assigning the value to a variable and checking for NULL, this is clearer and can be more efficient.
You can try this with if(#FechaInicial IS NULL) as below.
declare #FechaInicial datetime
set #FechaInicial = (select FecharIncialDescarga from Contenedores
where Id_Contenedor=#IdContenedor)
if(#FechaInicial IS NULL) ---
begin
end
If you want to check NULL and also empty, you can try if(ISNULL(#FechaInicial, '') = '') as below.
declare #FechaInicial datetime
set #FechaInicial = (select FecharIncialDescarga
from Contenedores where Id_Contenedor=#IdContenedor)
if(ISNULL(#FechaInicial, '') = '') ---
begin
end
Also a recommendation, Instead of a SET used above, you can refactor it as below with a SELECT
SELECT #FechaInicial = FecharIncialDescarga
FROM Contenedores WHERE Id_Contenedor = #IdContenedor
I am trying to come up with a sql statement which converts the odometer if stored in km to miles. If the odometer is stored in miles, it leaves as it is.
After the conversion, it then needs to check for Search paramters i.e Mileage.
The steps I have taken is using the Case Statement.
Here is my snippet of the select statement that I am using currently:
DECLARE
#Mileage NVARCHAR(75) = NULL,
#IsMiles BIT = 1,
#Converted NVARCHAR(75) = NULL
SELECT [Id],Odometer,IsMiles,
CASE IsMiles when 0 THEN OdometerValue * 0.62137
else Odometer end
FROM [dbo].[Vehicle]
where IsMiles = 0
Is there anyway to pass the Result of the case statement to ConvertedOdometer. I want to use that value to evaluate against the search Mileage parameters.
Something like this with this condition:
(ConvertedOdometer >=0 AND ConvertedOdometer <= #Mileage)
I am new to Case statement so have used these guides:
StackOverflow
Sql School
Some Blog
Perhaps something like this ...
DECLARE
#Mileage NVARCHAR(75) = NULL,
#IsMiles BIT = 1,
#Converted NVARCHAR(75) = NULL
select a.* from
(SELECT [Id],Odometer,IsMiles,
CASE when IsMiles=0 THEN OdometerValue * 0.62137 else Odometer end as ConvertedOdometer
FROM [dbo].[Vehicle]
where IsMiles = 0)a
where a.ConvertedOdometer >=0 AND
a.ConvertedOdometer <= #Mileage
I have a code in VB.Net application which I would like to move to stored procedure.
VB code looks something like this :
if(id == 3)
{
var year = Year(invoiceDate)
updatedDate = DateSerial(dueYear, DueDateMonth, DueDateDay)
If updatedDate < invoiceDate Then
updatedDate += 1
updatedDate = DateSerial(updatedDate , getMonthFromDBTable, getDayFromDBTable)
End If
}
This is part of a condition which I am trying to resolve.
Currently in SQL I have the following
DECLARE #tmpCalendarDate DATETIME;
DECLARE #tmpYear int;
SET #tmpCalendarDate = convert(varchar(10), getdate(),120);
SET #tmpYear = DATEPART(yyyy, #tmpCalendarDate);
SELECT COALESCE (
CASE WHEN tt.ID = 1 THEN DATEADD(day, t.DaysUntilDue, r.InvoiceDate) END,
CASE WHEN tt.ID = 3 THEN -- This is where I need to add the condition.
I was thinking of setting the #tmpCalendarDate with the values to look something like
CASE WHEN tt.ID = 3 THEN #tmpCalendarDate = '#tmpYear-t.DueDateMonth-t.DueDateDay'
where t is a table.
This value cannot be changed, so I would rather calculate and fetch it once rather than calculating it every time binding changes (wpf application).
Any help is greatly appreciated.
UPDATE: I realized maybe I am vague with my question, so here it is
How do i set #tmpCalendarDate? I tried
SELECT #tmpCalendarDate = '#tmpYear-t.DueDateMonth-t.DueDateDay' FROM table t
and I get an error 'Conversion failed when converting date and/or time from character string.' Instead I am expecting something like #tmpCalendarDate to be set to '2016-03-12'
Also, can I add an If..Else condition inside CASE.Then
In my example:
CASE WHEN tt.ID = 3 THEN #tmpCalendarDate = '#tmpYear-t.DueDateMonth-t.DueDateDay'
IF (#tmpCalendarDate > InvoiceDate)
BEGIN
--Do some logic
END
ELSE
--Do some logic
BEGIN
END
You can use DATEFROMPARTS
#tmpCalendarDate = DATEFROMPARTS(#tmpyear, t.DueDateMonth, t.DueDateDay)
Your mistake in your original attempt is you are setting #tempCalendarDate to actual string #tmpYear-t.DueDateMonth-t.DueDateDay which results in a conversion error.
I am writing a stored proc that calculates a WHOLE bunch of different things, but I have a bit in it, that is repeated about 9 times.
eg:
if #argA = 1 (true)
select Count(samples) from dbo.X where type = #argAType
if #argB = 1 (true)
select Count(samples) from dbo.X where type = #argBType
if #argC = 1
select Count(samples) from dbo.X where type = #argCType
and so on...
how can I write a function (or something similar) that I can pass in a bit (true or false), and other argument, and only return the result set if true???
Is this what you're looking for? This is the best I can deduce based on the question as it's currently posted.
SELECT COUNT(samples)
FROM dbo.X
WHERE
(type=#argAType AND #argA=1)
OR
(type=#argBType AND #argB=1)
OR
(type=#argCType AND #argC=1)
In function form, I think this is right:
CREATE FUNCTION GetCount(#n AS BIGINT) RETURNS BIGINT
AS
BEGIN
DECLARE #count BIGINT
SELECT #count = COUNT(samples)
FROM dbo.X
WHERE
(type=#argAType AND #argA=1)
OR
(type=#argBType AND #argB=1)
OR
(type=#argCType AND #argC=1)
RETURN #count
END