根据字段1中的唯一值在SQL表中多次插入同一行

Question

I currently have a table where column 1 is a unique identifier for the remaining columns and I need to insert a new value into the table for each unique identifier. The example is as follows:

Column 1   Column 2   Column 3 
10         Address    True 
10         City       False
10         State      True
20         Address    True
20         City       True
20         State      True

I need to insert a new row based upon each unique identifier in Column 1, like so:

Column 1   Column 2   Column 3
10         Address    True
10         City       False
10         State      True
*10         NEW        NEW*
20         Address    True
20         City       True
20         State      True
*20         NEW        NEW*

For some reason, the SQL script for the quick lookup and insert is just escaping me on a Monday morning. Any help would be appreciated.

Thanks!

Answer 1

insert into table-name
(Column1, Column2, Column3)
select Column1, 'NEW', 'NEW*' from table-name group by Column1

You can alternatively use a distinct in the sub-select, but I have started switching to group by, which can be more flexible if I want to change a query to count or something.

Answer 2

You can try at variant of Marlin Pierce's suggestion of:

INSERT INTO [table-name]
([Column 1], [Column 2], [Column 3])
SELECT [Column 1], 'NEW', 'NEW*' from [table-name] where [Column 2] = 'Address' group by [Column 1];

This creates a single new row for each of your existing rows.

See the SqlFiddle for executable sample.