---
title: "EventLog Event Class | Microsoft Docs"
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ms.date: "06/13/2017"
ms.prod: "sql-server-2014"
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ms.topic: conceptual
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  - "EventLog event class"
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author: stevestein
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---
# EventLog Event Class
  The EventLogevent class indicates that events have been logged in the [!INCLUDE[msCoName](../../includes/msconame-md.md)] Windows event log.  
  
## EventLog Event Class Data Columns  
  
|Data column name|Data type|Description|Column ID|Filterable|  
|----------------------|---------------|-----------------|---------------|----------------|  
|ApplicationName|`nvarchar`|Name of the client application that created the connection to an instance of [!INCLUDE[msCoName](../../includes/msconame-md.md)] [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)]. This column is populated with the values passed by the application rather than the displayed name of the program.|10|Yes|  
|BinaryData|`image`|Binary value dependent on the event class captured in the trace.|2|Yes|  
|ClientProcessID|`int`|ID assigned by the host computer to the process where the client application is running. This data column is populated if the client provides the client process ID.|9|Yes|  
|DatabaseID|`int`|ID of the database specified by the USE *database* statement or the default database if no USE *database* statement has been issued for a given instance. [!INCLUDE[ssSqlProfiler](../../includes/sssqlprofiler-md.md)] displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function.|3|Yes|  
|DatabaseName|`nvarchar`|Name of the database in which the user statement is running.|35|Yes|  
|Error|`int`|Error number of a given event, if available.|31|Yes|  
|EventClass|`int`|Type of event = 21.|27|No|  
|EventSequence|`int`|Sequence of a given event within the request.|51|No|  
|HostName|`nvarchar`|Name of the computer on which the client is running. This data column is populated if the client provides the host name. To determine the host name, use the HOST_NAME function.|8|Yes|  
|IsSystem|`int`|Indicates whether the event occurred on a system process or a user process. 1 = system, 0 = user.|60|Yes|  
|LoginName|`nvarchar`|Name of the login of the user (either [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] security login or the Windows login credentials in the form of DOMAIN\username).|11|Yes|  
|LoginSid|`image`|Security identifier (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server.|41|Yes|  
|NTDomainName|`nvarchar`|Windows domain to which the user belongs.|7|Yes|  
|NTUserName|`nvarchar`|Windows user name.|6|Yes|  
|RequestID|`int`|ID of the request containing the statement.|49|Yes|  
|ServerName|`nvarchar`|Name of the instance of [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] being traced.|26|No|  
|SessionLoginName|`nvarchar`|Login name of the user who originated the session. For example, if you connect to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] using Login1 and execute a statement as Login2, SessionLoginName shows Login1 and LoginName shows Login2. This column displays both [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] and Windows logins.|64|Yes|  
|Severity|`int`|Severity level of an exception.|20|Yes|  
|SPID|`int`|ID of the session on which the event occurred.|12|Yes|  
|StartTime|`datetime`|Time at which the event started, if available.|14|Yes|  
|TextData|`ntext`|Text of the error message, if available.|1|Yes|  
|TransactionID|`bigint`|System-assigned ID of the transaction.|4|Yes|  
  
## See Also  
 [Extended Events](../extended-events/extended-events.md)   
 [sp_trace_setevent (Transact-SQL)](/sql/relational-databases/system-stored-procedures/sp-trace-setevent-transact-sql)