Question

I have a table like the following one

CREATE TABLE [dbo].[MyTable](
    [MyTableID]    [int]           IDENTITY(1,1) NOT NULL,
    [ContainerID]  [int]           NOT NULL,
    [FIELD_A]      [nvarchar](15)  NOT NULL,
    [FIELD_B]      [nvarchar](15)  NOT NULL,
    [FIELD_C]      [nvarchar](15)  NOT NULL,
    [FIELD_D]      [nvarchar](50)  NULL,
 CONSTRAINT [PK_MyTable] PRIMARY KEY CLUSTERED ( [MyTableID] ASC )
    WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF,
    ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 80) ON [PRIMARY]
) ON [PRIMARY]

In simple terms FIELD_A, FIELD_B, FIELD_C and FIELD_D are grouped by ContainerID.

Considering that each container contains about 2k records, I would like to execute a query that returns the differences between two ContainerID. For example, while comparing container 1 and container 2, I need to know:

• How many records are present in 1 and not in 2 and vice versa
• How many records are present in both containers

Which is the simplest way to get those results?
Thanks!

Answer 1

Here is a start:

-- rows for 1 but not in 2:

SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 1
EXCEPT
SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 2;

-- rows for 2 but not in 1:

SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 2
EXCEPT
SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 1;

-- rows in both:

SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 1
INTERSECT
SELECT FIELD_A, FIELD_B, FIELD_C, FIELD_D FROM dbo.MyTable WHERE ContainerID = 2;