Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
ronstone
Starting Member
32 Posts |
 Posted - 2004-02-27 : 10:00:26
|
| If someone knows the behavior, it would save me time in testing this out...If I truncate a table that has an identity column, then insert into the table (from an identical table with less rows) with identity_insert ON, will SQL be smart enough to know which identity to correctly use for subsequent row inserts?I need to copy the identity column because this column is used as a foreign key on another table.Thanks!Ron |
|
|
ronstone
Starting Member
32 Posts |
Posted - 2004-02-27 : 10:14:31
|
| Update!First I truncated the table.Ran DBCC CHECKIDENT (tablename, noreseed). This reports the current identity. It was reset to 1.Imported the table with the identity_insert ON. Ran DBCC CHECKIDENT (tablename, noreseed) again. It showed the current max(identitycolumnvalue). So, it looks like on the insert, it reseeded to the maximum value. |
 |
|
|
ronstone
Starting Member
32 Posts |
Posted - 2004-02-27 : 10:28:27
|
| Sorry, another update.When you DELETE FROM Table, the Identity does NOT get reseeded. TRUNCATE does reseed to 1. |
|
|
|
nr
SQLTeam MVY
12543 Posts |
Posted - 2004-02-27 : 10:54:05
|
| Truncate will set the seed to the original value.When a row is inserted with identity_insert - if the value is greater than the current seed (or less if the value is set to decrease) then the new value is used if not the seed is unchanged.==========================================Cursors are useful if you don't know sql.DTS can be used in a similar way.Beer is not cold and it isn't fizzy. |
|
|
|
|
|
|
TRUNCATING and Enabling INDENTITY_INSERT