This query works, but seems terribly inefficient. There has to be a better way?
What I am trying to do is select 4 different columns from a MarketRates table based on which territory a company is in. There are only 4 Territories, stored as an integer 1-4 in the Company table. So for instance, if the Territory is "1", then I want to select the 4 Southern California columns (column names are SCA*), but if the Territory is "2", then I want to select the 4 Norhtern California columns (column names are NCA*), etc.
I know the tables should be constructed differently, but this is what I have to deal with.
The MarketRates table contains these columns (SCA = Southern California, NCA = Northern California, SNV = Southern Nevada, NAZ = Northern Arizona:
- EndingDate - date
- SCA_MRK - decimal (8,2)
- SCA_RATE - decimal (8,2)
- SCA_COMP - decimal (8,2)
- SCA_NEG - decimal (8,2)
- NCA_MRK - decimal (8,2)
- NCA_RATE - decimal (8,2)
- NCA_COMP - decimal (8,2)
- NCA_NEG - decimal (8,2)
- SNV_MRK - decimal (8,2)
- SNV_RATE - decimal (8,2)
- SNV_COMP - decimal (8,2)
- SNV_NEG - decimal (8,2)
- NAZ_MRK - decimal (8,2)
- NAZ_RATE - decimal (8,2)
- NAZ_COMP - decimal (8,2)
- NAZ_NEG - decimal (8,2)
This is the current query that I am using:
Select CompanyName
, case TerritoryNumber
when 1 then (Select top 1 coalesce(SCA_MRK,0) From MarketRates Order by EndingDate desc)
when 2 then (Select top 1 coalesce(NCA_MRK,0) From MarketRates Order by EndingDate desc)
when 3 then (Select top 1 coalesce(SNV_MRK,0) From MarketRates Order by EndingDate desc)
when 4 then (Select top 1 coalesce(NAZ_MRK,0) From MarketRates Order by EndingDate desc)
end AS MRK
, case TerritoryNumber
when 1 then (Select top 1 coalesce(SCA_RATE,0) From MarketRates Order by EndingDate desc)
when 2 then (Select top 1 coalesce(NCA_RATE,0) From MarketRates Order by EndingDate desc)
when 3 then (Select top 1 coalesce(SNV_RATE,0) From MarketRates Order by EndingDate desc)
when 4 then (Select top 1 coalesce(NAZ_RATE,0) From MarketRates Order by EndingDate desc)
end AS RATE
, case TerritoryNumber
when 1 then (Select top 1 coalesce(SCA_COMP,0) From MarketRates Order by EndingDate desc)
when 2 then (Select top 1 coalesce(NCA_COMP,0) From MarketRates Order by EndingDate desc)
when 3 then (Select top 1 coalesce(SNV_COMP,0) From MarketRates Order by EndingDate desc)
when 4 then (Select top 1 coalesce(NAZ_COMP,0) From MarketRates Order by EndingDate desc)
end AS COMP
, case TerritoryNumber
wh开发者_JS百科en 1 then (Select top 1 coalesce(SCA_NEG,0) From MarketRates Order by EndingDate desc)
when 2 then (Select top 1 coalesce(NCA_NEG,0) From MarketRates Order by EndingDate desc)
when 3 then (Select top 1 coalesce(SNV_NEG,0) From MarketRates Order by EndingDate desc)
when 4 then (Select top 1 coalesce(NAZ_NEG,0) From MarketRates Order by EndingDate desc)
end AS NEG
from Company
where CompanyID = 'THISID'
You should only have to select your 1 row from MarketRates once since you're referencing the same row each time. Select it in a sub-query and join to it and you can reference that throughout the query. I re-wrote what MRK would look like, similar syntax/logic for the other columns as well.
Select CompanyName
, case TerritoryNumber
when 1 then coalesce(SCA_MRK,0)
when 2 then coalesce(NCA_MRK,0)
when 3 then coalesce(SNV_MRK,0)
when 4 then coalesce(NAZ_MRK,0)
end AS MRK
, ...etc
from Company
cross join (select top 1 * from MarketRates order by EndingDate desc) MarketRates
where CompanyID = 'THISID'
DECLARE
@TerritoryID INT,
@CompanyName VARCHAR(32);
SELECT
@CompanyName = CompanyName,
@TerritoryID = TerritoryNumber
FROM Company
WHERE CompanyID = 'THISID';
SELECT TOP 1
CompanyName = @CompanyName,
MRK = CASE @TerritoryID
WHEN 1 THEN SCA_MRK
WHEN 2 THEN NCA_MRK
WHEN 3 THEN SNV_MRK
WHEN 4 THEN NAZ_MRK END,
RATE = CASE @TerritoryID
WHEN 1 THEN SCA_RATE
WHEN 2 THEN NCA_RATE
WHEN 3 THEN SNV_RATE
WHEN 4 THEN NAZ_RATE END,
COMP = CASE @TerritoryID
WHEN 1 THEN SCA_COMP
WHEN 2 THEN NCA_COMP
WHEN 3 THEN SNV_COMP
WHEN 4 THEN NAZ_COMP END,
NEG = CASE @TerritoryID
WHEN 1 THEN SCA_NEG
WHEN 2 THEN NCA_NEG
WHEN 3 THEN SNV_NEG
WHEN 4 THEN NAZ_NEG END
FROM MarketRates
ORDER BY EndingDate DESC;
You could keep it clean and faster with one case block. (You can replace the variable types to match your column datatype.) Check the dynamic SQL created below.
DECLARE @CompanyName varchar(50), @TerritoryNum int, @ColumnType varchar(10), @SQL VARCHAR(1000);
SELECT @CompanyName = CompanyName ,@TerritoryNum = TerritoryNumber
FROM Company WHERE CompanyID = 'THISID'
SET @ColumnType = CASE @TerritoryNum WHEN 1 THEN 'SCA_'
WHEN 2 THEN 'NCA_'
WHEN 3 THEN 'SNV_'
WHEN 4 THEN 'NAZ_'
END
SET @SQL = '
SELECT
''' + @CompanyName + ''' AS CompanyName,
COALESCE(' + @ColumnType + 'MRK,0) AS MRK,
COALESCE(' + @ColumnType + 'RATE,0) AS RATE,
COALESCE(' + @ColumnType + 'COMP,0) AS COMP,
COALESCE(' + @ColumnType + 'NEG,0) AS NEG
FROM MarketRates
'
PRINT @SQL
EXEC(@SQL)
The dynamic query (can be seen from the Print) would be as simple as below where the Company table has 'Comp' in CompanyName column and 2 in TerritoryNumber column. Try changing this to other numbers in the Company table and the appropriate MarketRates columns should figure in the dynamic query.
SELECT
'Comp' AS CompanyName,
COALESCE(NCA_MRK,0) AS MRK,
COALESCE(NCA_RATE,0) AS RATE,
COALESCE(NCA_COMP,0) AS COMP,
COALESCE(NCA_NEG,0) AS NEG
FROM MarketRates
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