合并以更新所有目标表列

Question

I have the same table in 2 Databases

-----------------------------------
|           table                 |
-----------------------------------
| ID | col1 | col2 | ... | col(n) |

I need merge statement to update rows with matched IDs like this statement:

MERGE [DB1]..[table]
USING [DB2]..[table] ON [DB1]..[table].[ID] = [DB2]..[table].[ID]
WHEN MATCHED THEN
    UPDATE SET [DB1]..[table].[*] = [DB1]..[table].[*]

the problem is I have more than 30 columns so its difficult to set values column by column .

Answer 1

There is no way to use a wildcard to specify the target update columns and mappings (even if all columns are identical). You can get a head start on all the typing by clicking on the Columns node in Object Explorer, and dragging it (and hence the column names) onto your query window:

So now you don't have all that much typing to do, just a bunch of manipulation and copying and pasting.

And I wouldn't use MERGE for this anyway, for various reasons (including the fact that the syntax is rather cumbersome when only an UPDATE is involved), and as mentioned in my comment above. See this post for details .

UPDATE trg
  SET col1 = src.col1,
      col2 = src.col2, 
      ...
  FROM DB1.dbo.table AS trg
  INNER JOIN DB2.dbo.table AS src
    ON trg.ID = src.ID;

Answer 2

I think @AaronBertrand is right for this question. MERGE Statement is not required. You can just write simple update statement(with join if necessary).

1) Simple update

       UPDATE TableName
          SET col1 ='what you want to update'

2) Two or multiple Updates

  UPDATE t2
    SET t2.col2 =t.col2,
       t2.col3 =t1.col3,
       t2.col4 =t.col5

    FROM Table t 
    INNER JOIN Table1 t1 on t1.col1=t.col1 
    INNER JOIN Table2 t2 on t2.col1=t1.col1