Cannot insert explicit value for identity column in table 'Department' when IDENTITY_INSERT is set to OFF.

It may be that the connection pool uses different connections. After execution SET identity_insert [Table] ON, it explicitly inserts the identity column reports an error, even request in the same transaction.

  it('mssql -> trans identity_insert on', async () => {
    dbConfig.server = dbConfig.host
    const pool = await require('mssql').connect(dbConfig)
    const trans = pool.transaction()
    await trans.begin()
    try {
      const req = trans.request()
      await req.query('SET identity_insert [Items] ON')
      const req2 = trans.request()
      // id is the identity column
      await req2.query("INSERT INTO [Items](Fid, Fname) VALUES(1, 'aName')")
      // throw error: Cannot insert explicit value for identity column in table 'Department' when IDENTITY_INSERT is set to OFF.
      await trans.commit()
    } catch (ex) {
      await trans.rollback()
      throw ex
    }
  })

[jacargentina]

@dhensby I’ve refactored to this, and it works!

await req.query('SET identity_insert [Items] ON; INSERT items(Oid....) VALUES(1, ....)')

[dhensby]

You would need to use a transaction. There is no guarantee that the pool will release the same connection both times so each query will be run on different connections.