Scope_identity() in batched sqlclient commands

北城余情 提交于 2019-12-31 05:01:06

问题


I usually use a stored procedure when inserting records to make sure I get the correct scope_identity() value. I have a requirement to get the id field of an inserted record when using SqlClient now.

My understanding is that if I batch the scope_identity() command with the insert then it will still be in the same scope as the insert command? Something like below. Hard to verify though... Will I 100% get the correct id value with this..?

(id field is an auto-incrementing bigint - Sql Server)

long newid = 0;

using (SqlConnection conn = new SqlConnection(....))
{
    conn.Open();
    using (SqlCommand comm = new SqlCommand ("insert into .... ; select SCOPE_IDENTITY();", conn))
    {
        SqlDataReader reader = comm.ExecuteReader();
        if (reader.HasRows)
        {
            reader.Read();
            newid = Convert.ToInt64(reader[0]);
        }
    }
}

回答1:


From the documentation for SCOPE_IDENTITY (emphasis mine):

Returns the last identity value inserted into an identity column in the same scope. A scope is a module: a stored procedure, trigger, function, or batch. Therefore, two statements are in the same scope if they are in the same stored procedure, function, or batch.

In this case, your command:

"insert into .... ; select SCOPE_IDENTITY();"

Is a batch, and therefore, you will get the last inserted identity value in that batch, which in this case is the identity value in the insert, since it's the only other statement in the batch.



来源:https://stackoverflow.com/questions/9675364/scope-identity-in-batched-sqlclient-commands

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