Источник ошибки net sqlclient data provider

By default login failed error message is nothing but a client user connection has been refused by the server due to mismatch of login credentials. First task you might check is to see whether that user has relevant privileges on that SQL Server instance and relevant database too, thats good. Obviously if the necessary prvileges are not been set then you need to fix that issue by granting relevant privileges for that user login.

Althought if that user has relevant grants on database & server if the Server encounters any credential issues for that login then it will prevent in granting the authentication back to SQL Server, the client will get the following error message:

Msg 18456, Level 14, State 1, Server <ServerName>, Line 1
Login failed for user '<Name>'

Ok now what, by looking at the error message you feel like this is non-descriptive to understand the Level & state. By default the Operating System error will show ‘State’ as 1 regardless of nature of the issues in authenticating the login. So to investigate further you need to look at relevant SQL Server instance error log too for more information on Severity & state of this error. You might look into a corresponding entry in log as:

2007-05-17 00:12:00.34 Logon     Error: 18456, Severity: 14, State: 8.
or

2007-05-17 00:12:00.34 Logon     Login failed for user '<user name>'.

As defined above the Severity & State columns on the error are key to find the accurate reflection for the source of the problem. On the above error number 8 for state indicates authentication failure due to password mismatch. Books online refers: By default, user-defined messages of severity lower than 19 are not sent to the Microsoft Windows application log when they occur. User-defined messages of severity lower than 19 therefore do not trigger SQL Server Agent alerts.

Sung Lee, Program Manager in SQL Server Protocols (Dev.team) has outlined further information on Error state description:The common error states and their descriptions are provided in the following table:

ERROR STATE       ERROR DESCRIPTION
------------------------------------------------------------------------------
2 and 5           Invalid userid
6                 Attempt to use a Windows login name with SQL Authentication
7                 Login disabled and password mismatch
8                 Password mismatch
9                 Invalid password
11 and 12         Valid login but server access failure
13                SQL Server service paused
18                Change password required


Well I'm not finished yet, what would you do in case of error:

2007-05-17 00:12:00.34 Logon     Login failed for user '<user name>'.

You can see there is no severity or state level defined from that SQL Server instance’s error log. So the next troubleshooting option is to look at the Event Viewer’s security log [edit because screen shot is missing but you get the

idea, look in the event log for interesting events].

случилось первый раз 3 недели назад
веб запрос типа:

1

cmd.CommandText = "UPDATE  Заявки SET [приоритет] = @приоритет, [Срок] = '" + Срок + "' WHERE ([ID_Заявка] = " + номер + ")";

на изменение записи в таблице SQL сервера выдал ошибку.
в тоже самое время изменение других записей этой же таблице отрабатывается нормально.
пробую изменить «противную» строку через SQL Server Management Studio прямо в таблице…
ага.
«Строки не были обновлены.
Данные в строке не были зафиксированы.
Источник ошибки: .Net SqlClient Data Provider.
Сообщение об ошибке: Время ожидания выполнения истекло…»

запросом:

1
2
3

UPDATE [dbo].[Заявки]
SET [приоритет] = 'Низкий ' 
WHERE [ID_Заявка] = '1836'

— выполнение зависает, долго не жду — останавливаю, так как «подвисает» вся база.

ничего толкового сделать не успел. проблема «рассосалась» сама через некоторое время.
сегодня повторилось тоже самое.

что с этим делать? как бороться?

SQL Server Express (64-bit) 2012

Здравствуйте, хотел запустить sql сервер от имени пользователя sa, и наткнулся на ошибку, прошу помощи, кто сталкивался?

Не удается подключиться к SQL1.

===================================

Ошибка входа пользователя «sa». (.Net SqlClient Data Provider)

——————————
Чтобы получить справку, щелкните: go.microsoft.com/fwlink?ProdName=Microsoft%20SQL%2…

——————————
Имя сервера: SQL1
Номер ошибки: 18456
Серьезность: 14
Состояние: 1
Номер строки: 65536

Hello Team,

I have create SQL user «Test02» to connect SQL 2014 database using SQL Studio. 
Server Role: Public & user mapping: testdatabase and public membership.
When i am trying to login with «test» user with passwor, the system is showing below error.
Login failed for user ‘Test02’. (.Net SqlClient Data Provider)

——————————
For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft%20SQL%20Server&EvtSrc=MSSQLServer&EvtID=18456&LinkId=20476

——————————
Server Name: LCSRVR03LCSQLEXP
Error Number: 18456
Severity: 14
State: 1
Line Number: 65536

——————————
Program Location:

   at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance,
SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling)
   at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at Microsoft.SqlServer.Management.SqlStudio.Explorer.ObjectExplorerService.ValidateConnection(UIConnectionInfo ci, IServerType server)
   at Microsoft.SqlServer.Management.UI.ConnectionDlg.Connector.ConnectionThreadUser()

I have verified authentication mode also (Mixed mode), but still throwing the same error.

Waiting for advises.

Thanks
Santhosh G