how can i make this proc better? - sql

Question

i want to know how i can rewrite this SQL into a single select using joins. i have a long drawn out way as seen below to basically get the min date of a "project inception milestone" and max date for a "production go-live" milestone.
some background is the sql is for a project management application that tracks projects milestones against a release baseline set of milestones. I need to have a proc that takes a CSV list of projectIDs and have it select the min startDate for the project inception milestone (StatusCode.cid =37) and the max production go-live milestone(StatusCode.cid =77)
here is my dummy SQL i have working now:
CREATE PROC rpt_rainbow
#ProjectIDs NVARCHAR(1000)
AS
DECLARE #MinBRSProjectStartDate DATETIME
DECLARE #MinBRSReleaseStartDate DATETIME
DECLARE #MaxProdProjectEndDate DATETIME
DECLARE #MaxProdReleaseEndDate DATETIME
SELECT #MinBRSProjectStartDate = MIN (pm.startDate)
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID AND pm.ProjectID IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
WHERE sc.cid =37
SELECT #MinBRSReleaseStartDate = MIN(rel.startDate)
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID AND rel.milestonecid IN (37)
WHERE ProjectId IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
SELECT #MaxProdProjectEndDate = MAX (pm.endDate)
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID AND pm.ProjectID IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
WHERE sc.cid =77
SELECT #MaxProdReleaseEndDate = MAX(rel.endDate)
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID AND rel.milestonecid IN (77)
WHERE ProjectId IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
select isnull(#MinBRSProjectStartDate, #MinBRSReleaseStartDate) as MinBRS_StartDate,
isnull(#MaxProdProjectEndDate, #MaxProdReleaseEndDate) as MaxProd_EndDate
here is my split function:
CREATE FUNCTION dbo.Split
( #Delimiter varchar(5),
#List varchar(8000)
)
RETURNS #TableOfValues table
( RowID smallint IDENTITY(1,1),
[Value] varchar(50)
)
AS
BEGIN
DECLARE #LenString int
WHILE len( #List ) > 0
BEGIN
SELECT #LenString =
(CASE charindex( #Delimiter, #List )
WHEN 0 THEN len( #List )
ELSE ( charindex( #Delimiter, #List ) -1 )
END
)
INSERT INTO #TableOfValues
SELECT substring( #List, 1, #LenString )
SELECT #List =
(CASE ( len( #List ) - #LenString )
WHEN 0 THEN ''
ELSE right( #List, len( #List ) - #LenString - 1 )
END
)
END
RETURN
END
and here are the definitions for the tables involved:
CREATE TABLE [dbo].[ProjectMilestone](
[ProjectMilestoneId] [int] NOT NULL,
[ProjectId] [int] NOT NULL,
[MilestoneCID] [int] NOT NULL,
[StartDate] [datetime] NOT NULL,
[EndDate] [datetime] NOT NULL,
[RAGStatusCID] [int] NOT NULL,
[CompletionStatusCID] [int] NOT NULL,
[StatusText] [nvarchar](max) NOT NULL,
[ReportingPriority] [int] NULL,
[Owner] [nvarchar](50) NOT NULL,
[Added] [datetime] NOT NULL,
[LastUpdate] [datetime] NOT NULL,
[UpdateBy] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_ProjectMilestone] PRIMARY KEY CLUSTERED
(
[ProjectMilestoneId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[ProjectMilestone] WITH CHECK ADD CONSTRAINT [FK_ProjectMilestone_Project] FOREIGN KEY([ProjectId])
REFERENCES [dbo].[Project] ([ProjectId])
GO
ALTER TABLE [dbo].[ProjectMilestone] CHECK CONSTRAINT [FK_ProjectMilestone_Project]
-----------------------------------------------------------------------------------------------
CREATE TABLE [dbo].[Project](
[ProjectId] [int] NOT NULL,
[ProjectName] [nvarchar](255) NOT NULL,
[ProjectRegistration] [nvarchar](50) NOT NULL,
[CaseManagerBenId] [nvarchar](50) NOT NULL,
[ClarityId] [nvarchar](50) NOT NULL,
[ParentProjectId] [int] NULL,
[ReleaseId] [int] NOT NULL,
[CompletionStatusCID] [int] NOT NULL,
[ProjectTypeCID] [int] NOT NULL,
[Budget] [money] NOT NULL,
[BusinessObjective] [nvarchar](max) NOT NULL,
[Benefit] [nvarchar](max) NOT NULL,
[Added] [datetime] NOT NULL,
[LastUpdate] [datetime] NOT NULL,
[UpdateBy] [nvarchar](50) NOT NULL,
[StakeholderList] [nvarchar](1000) NULL,
CONSTRAINT [PK_Project] PRIMARY KEY CLUSTERED
(
[ProjectId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[Project] WITH CHECK ADD CONSTRAINT [FK_Project_Project] FOREIGN KEY([ParentProjectId])
REFERENCES [dbo].[Project] ([ProjectId])
GO
ALTER TABLE [dbo].[Project] CHECK CONSTRAINT [FK_Project_Project]
GO
ALTER TABLE [dbo].[Project] WITH CHECK ADD CONSTRAINT [FK_Project_Release] FOREIGN KEY([ReleaseId])
REFERENCES [dbo].[Release] ([ReleaseId])
GO
ALTER TABLE [dbo].[Project] CHECK CONSTRAINT [FK_Project_Release]
--------------------------------------------------------------------------------------------
CREATE TABLE [dbo].[StatusCode](
[CID] [int] NOT NULL,
[CodeName] [nvarchar](50) NOT NULL,
[Description] [nvarchar](max) NOT NULL,
[SCID] [int] NOT NULL,
[ReportingPriority] [int] NULL,
CONSTRAINT [PK_StatusCode] PRIMARY KEY CLUSTERED
(
[CID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
--------------------------------------------------------------------------------------------
CREATE TABLE [dbo].[ReleaseSchedule](
[ReleaseScheduleID] [int] NOT NULL,
[ReleaseID] [int] NOT NULL,
[MilestoneCID] [int] NOT NULL,
[StartDate] [datetime] NOT NULL,
[EndDate] [datetime] NOT NULL,
[Added] [datetime] NOT NULL,
[LastUpdate] [datetime] NOT NULL,
[UpdateBy] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_ReleaseSchedule] PRIMARY KEY CLUSTERED
(
[ReleaseScheduleID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[ReleaseSchedule] WITH CHECK ADD CONSTRAINT [FK_ReleaseSchedule_Release] FOREIGN KEY([ReleaseID])
REFERENCES [dbo].[Release] ([ReleaseId])
GO
ALTER TABLE [dbo].[ReleaseSchedule] CHECK CONSTRAINT [FK_ReleaseSchedule_Release]

Answer 1

There are two things of note, the first is that you could reduce the 4 queries to 2
SELECT
#MinBRSProjectStartDate = MIN (CASE WHEN sc.cid=37 then pm.startDate END),
#MaxProdProjectEndDate = MAX (CASE WHEN sc.cid=77 then pm.endDate END)
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID
AND pm.ProjectID IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
WHERE sc.cid in (37,77)
SELECT
#MinBRSReleaseStartDate = MIN(CASE WHEN rel.milestonecid=37 then rel.startDate end),
#MaxProdReleaseEndDate = MAX(CASE WHEN rel.milestonecid=77 then rel.endDate end)
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID AND rel.milestonecid IN (37,77)
WHERE ProjectId IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
There is really no way to join between these two sets, so there is no point trying. But you could CROSS JOIN the two single-row results to get all 4 columns in a single select:
SELECT ISNULL(A,C) as MinBRS_StartDate, ISNULL(B,D) AS MaxProd_EndDate
FROM
(
SELECT
MIN (CASE WHEN sc.cid=37 then pm.startDate END) A,
MAX (CASE WHEN sc.cid=77 then pm.endDate END) B
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID
AND pm.ProjectID IN (SELECT value FROM fn_Split(#ProjectIDs, ','))
WHERE sc.cid in (37,77)
) X,
(
SELECT
MIN(CASE WHEN rel.milestonecid=37 then rel.startDate end) C,
MAX(CASE WHEN rel.milestonecid=77 then rel.endDate end) D
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID AND rel.milestonecid IN (37,77)
WHERE ProjectId IN (SELECT value FROM fn_Split(#ProjectIDs, ','))) Y
But since you are using ISNULL across the 2 pairs, it may be better to keep the 4 targeted index-able selects and to just subquery them. Since you are using the SPLIT values 4 times, it makes sense to cache it in a temp table. The ISNULL should be smart enough not to need to evaluate the 2nd select once the first returns a value.
declare #ids table (id int)
insert #ids SELECT distinct value FROM fn_Split(',', #ProjectIDs) V
SELECT
ISNULL(
(SELECT MIN (pm.startDate)
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID
INNER JOIN #ids I ON pm.ProjectID = I.ID
WHERE sc.cid =37),
(SELECT MIN(rel.startDate)
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID
INNER JOIN #ids I ON p.ProjectID = I.ID
WHERE rel.milestonecid IN (37))) AS MinBRS_StartDate,
ISNULL(
(SELECT MAX (pm.endDate)
FROM StatusCode sc
INNER JOIN ProjectMilestone pm ON sc.CID = pm.MilestoneCID
INNER JOIN #ids I ON pm.ProjectID = I.ID
WHERE sc.cid =77),
(SELECT MAX(rel.endDate)
FROM Project p
INNER JOIN ReleaseSchedule rel ON rel.ReleaseID = p.ReleaseID
INNER JOIN #ids I ON p.ProjectID = I.ID
WHERE rel.milestonecid IN (77))) AS MaxProd_EndDate