How to Update Columns of a Table with two instance in one update Statement.

  • I have two tables Table1 and Table2 with ID in both tables. I want to update records of First table that matched with second table and also does not match with second Table.

    Currently, I am using two Statements to achieve this goal. I want this in one statement.

    Below script will explain whole things,

    CREATE TABLE [dbo].[Table2](

    [ID] [int] NULL,

    [Name2] [varchar](50) NULL

    ) ON [PRIMARY]

    GO

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (1, N'ABC')

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (2, N'CDE')

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (4, N'JKL')

    /****** Object: Table [dbo].[Table1] Script Date: 12/31/2012 16:39:43 ******/

    CREATE TABLE [dbo].[Table1](

    [ID] [int] NULL,

    [Name1] [varchar](50) NULL

    ) ON [PRIMARY]

    GO

    SET ANSI_PADDING OFF

    GO

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (1, N'ABC')

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (2, N'CDE')

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (3, N'XYZ')

    --Updat values in first table that exists in both tables

    update T1

    set

    T1.Name1='abc'

    from Table2 T2

    inner join Table1 T1 on t1.ID=T2.ID

    where T1.ID=1

    --Updat values in first table that exists in only first table tables

    Update T1

    set

    T1.Name1='xyz'

    from Table2 T2

    right outer join Table1 T1 on t1.ID=T2.ID

    where T2.ID is null

    AND T1.ID=3

    I need the updates in one statement instead of Two updates.

    Thanks in Advance.

  • I think the MERGE statement may work for you here. Have you tried that?

    John

  • no,

    would you please give me any clue of merge.

  • azhar.iqbal499 (12/31/2012)


    I have two tables Table1 and Table2 with ID in both tables. I want to update records of First table that matched with second table and also does not match with second Table.

    Currently, I am using two Statements to achieve this goal. I want this in one statement.

    Below script will explain whole things,

    CREATE TABLE [dbo].[Table2](

    [ID] [int] NULL,

    [Name2] [varchar](50) NULL

    ) ON [PRIMARY]

    GO

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (1, N'ABC')

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (2, N'CDE')

    INSERT [dbo].[Table2] ([ID], [Name2]) VALUES (4, N'JKL')

    /****** Object: Table [dbo].[Table1] Script Date: 12/31/2012 16:39:43 ******/

    CREATE TABLE [dbo].[Table1](

    [ID] [int] NULL,

    [Name1] [varchar](50) NULL

    ) ON [PRIMARY]

    GO

    SET ANSI_PADDING OFF

    GO

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (1, N'ABC')

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (2, N'CDE')

    INSERT [dbo].[Table1] ([ID], [Name1]) VALUES (3, N'XYZ')

    --Updat values in first table that exists in both tables

    update T1

    set

    T1.Name1='abc'

    from Table2 T2

    inner join Table1 T1 on t1.ID=T2.ID

    where T1.ID=1

    --Updat values in first table that exists in only first table tables

    Update T1

    set

    T1.Name1='xyz'

    from Table2 T2

    right outer join Table1 T1 on t1.ID=T2.ID

    where T2.ID is null

    AND T1.ID=3

    I need the updates in one statement instead of Two updates.

    Thanks in Advance.

    The CASE statement can help:

    UPDATE

    dbo.Table1

    SET

    Name1 = CASE WHEN T2.ID IS NULL THEN 'XYZ' ELSE 'ABC' END

    FROM

    dbo.Table1 T1

    LEFT OUTER JOIN

    dbo.Table2 T2

    ON

    T1.ID = T2.ID;

    Roland Alexander 
    The Monday Morning DBA 
    There are two means of refuge from the miseries of life: music and cats. ~ Albert Schweitzer

  • That code wasn't quite right:

    UPDATE

    dbo.Table1

    SET

    Name1 = CASE

    WHEN (T2.ID IS NULL AND T1.ID = 3) THEN 'XYZ'

    WHEN T1.ID = 3 THEN 'ABC'

    ELSE Name1 END

    FROM

    dbo.Table1 T1

    LEFT OUTER JOIN

    dbo.Table2 T2

    ON

    T1.ID = T2.ID;

    Roland Alexander 
    The Monday Morning DBA 
    There are two means of refuge from the miseries of life: music and cats. ~ Albert Schweitzer

  • Roland, I tweaked your query a little to include a WHERE clause & was consequently able to simplify the CASE construct. Also, your update needed to reference the alias (t1) rather than the table name:

    update T1

    set Name1 = case

    when T2.ID is null

    then 'XYZ'

    else 'ABC'

    end

    from dbo.Table1 T1

    left join dbo.Table2 T2 on T1.ID = T2.ID

    where (

    t1.Id = 1

    and t2.id is not null

    )

    or (

    t1.id = 3

    and t2.id is null

    )

    The absence of evidence is not evidence of absence
    - Martin Rees
    The absence of consumable DDL, sample data and desired results is, however, evidence of the absence of my response
    - Phil Parkin

  • Nicely done, Phil, thanks!

    Roland Alexander 
    The Monday Morning DBA 
    There are two means of refuge from the miseries of life: music and cats. ~ Albert Schweitzer

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