Usage of output in Sqlsevrer

Recently, see the code in the output wording, do not know its meaning, after a search, finally found the reason, its role is to modify the effect of the results to output.

For example, the UPDATE statement, in addition to modifying the data, can also return the value of the column before and after it has been updated. In other cases, such as troubleshooting, auditing, etc., such a feature is useful.

An INSERT statement with output.

@ @identity can only return the identity column that was last produced by the current session. If you insert more than one statement at a time. You need to return the identity columns for these automated productions. Then the OUTPU comes in handy.

int, v nvarchar (200))

into T1 (Datacol)

Output Inserted.keycol, Inserted.datacol

Into @temp

where country=' UK '

From @temp

Usage of output in Sqlsevrer