CODEWITHSUNDEEP
sql-servert-sqlconstraints
mark1234
mark1234

Reputation: 1121

T-SQL what kind of constraint to use

I have the following two tables (only relevant key columns shown)

CREATE TABLE [dbo].[Jobs](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [JobNo] [nvarchar](50) NOT NULL,
 CONSTRAINT [PK_Jobs] PRIMARY KEY CLUSTERED 
(
    [ID] 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].[Items](
    [JobID] [int] NOT NULL,
    [BarcodeNo] [nvarchar](50) NOT NULL,
    [SerialNo] [nvarchar](50) NOT NULL,

 CONSTRAINT [PK_Items_1] PRIMARY KEY CLUSTERED 
(
    [JobID] ASC,
    [BarcodeNo] ASC,
    [SerialNo] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

I need to make sure that when an item is entered, the JobID matches an ID in the Jobs table. It seems, I can't use a FK because the PK in the items table is a composite key of 3 columns.

TIA

Mark What kind of constraint can I use for this?

Upvotes: 1

Views: 80

Answers (1)

Martin Smith
Martin Smith

Reputation: 453047

A foreign key works fine.

There's no problem with having the single column [dbo].[Items].[JobID] reference the PK of jobs.

CREATE TABLE [dbo].[Jobs]
  (
     [ID]    [INT] IDENTITY(1, 1) NOT NULL,
     [JobNo] [NVARCHAR](50) NOT NULL,
     CONSTRAINT [PK_Jobs] PRIMARY KEY CLUSTERED ( [ID] 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].[Items]
  (
     [JobID]     [INT] NOT NULL REFERENCES [dbo].[Jobs]([ID]), /*<-- FK declaration*/
     [BarcodeNo] [NVARCHAR](50) NOT NULL,
     [SerialNo]  [NVARCHAR](50) NOT NULL,
     CONSTRAINT [PK_Items_1] PRIMARY KEY CLUSTERED ( [JobID] ASC, [BarcodeNo] ASC, [SerialNo] ASC )
    WITH (PAD_INDEX = OFF, 
          STATISTICS_NORECOMPUTE = OFF, 
          IGNORE_DUP_KEY = OFF, 
          ALLOW_ROW_LOCKS = ON, 
          ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
  )
ON [PRIMARY]

Upvotes: 6

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