从表中获取最后一条记录 ID 的最安全方法

Question

In SQL Server 2008 and higher what is the best/safest/most correct way

1. to retrieve the ID (based on autoincrementing primary key) out of the database table?
2. to retrieve the value of the last row of some other column (like, SELECT TOP 1 FROM Table ORDER BY DESC)?

Answer 1

SELECT IDENT_CURRENT('Table')

You can use one of these examples:

SELECT * FROM Table 
WHERE ID = (
    SELECT IDENT_CURRENT('Table'))

SELECT * FROM Table
WHERE ID = (
    SELECT MAX(ID) FROM Table)

SELECT TOP 1 * FROM Table
ORDER BY ID DESC

But the first one will be more efficient because no index scan is needed (if you have index on Id column).

The second one solution is equivalent to the third (both of them need to scan table to get max id).

Answer 2

1.  SELECT MAX(Id) FROM Table

Answer 3

Safest way will be to output or return the scope_identity() within the procedure inserting the row, and then retrieve the row based on that ID. Use of @@Identity is to be avoided since you can get the incorrect ID when triggers are in play.

Any technique of asking for the maximum value / top 1 suffers a race condition where 2 people adding at the same time, would then get the same ID back when they looked for the highest ID.

Answer 4

You can try:

SELECT id FROM your_table WHERE id = (SELECT MAX(id) FROM your_table)

Where id is a primary key of the your_table

Answer 5

I think this one will also work:

SELECT * FROM ORDER BY id DESC LIMIT 0 , 1

Answer 6

One more way -

select * from <table> where  id=(select max(id) from <table>)

Also you can check on this link -

http://msdn.microsoft.com/en-us/library/ms175098.aspx

Answer 7

如果你的意思是选择最后插入的记录的 ID，它的

SELECT @@IDENTITY FROM table

Answer 8

SELECT LAST(row_name) FROM table_name