sys.dm_exec_connections (Transact-SQL)
https://docs.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-views/sys-dm-exec-connections-transact-sql?view=sql-server-2017
APPLIES TO: 
SQL Server Azure SQL Database 
Azure SQL Data Warehouse Parallel Data Warehouse
Returns information about the connections established to this instance of SQL Server and the details of each connection. Returns server wide connection information for SQL Server. Returns current database connection information for SQL Database.
Note
To call this from Azure SQL Data Warehouse or Parallel Data Warehouse, use sys.dm_pdw_exec_connections (Transact-SQL).
| Column name | Data type | Description |
|---|---|---|
| session_id | int | Identifies the session associated with this connection. Is nullable. |
| most_recent_session_id | int | Represents the session ID for the most recent request associated with this connection. (SOAP connections can be reused by another session.) Is nullable. |
| connect_time | datetime | Timestamp when connection was established. Is not nullable. |
| net_transport | nvarchar(40) | Always returns Session when a connection has multiple active result sets (MARS) enabled.
Note: Describes the physical transport protocol that is used by this connection. Is not nullable. |
| protocol_type | nvarchar(40) | Specifies the protocol type of the payload. It currently distinguishes between TDS (TSQL) and SOAP. Is nullable. |
| protocol_version | int | Version of the data access protocol associated with this connection. Is nullable. |
| endpoint_id | int | An identifier that describes what type of connection it is. This endpoint_id can be used to query the sys.endpoints view. Is nullable. |
| encrypt_option | nvarchar(40) | Boolean value to describe whether encryption is enabled for this connection. Is not nullable. |
| auth_scheme | nvarchar(40) | Specifies SQL Server/Windows Authentication scheme used with this connection. Is not nullable. |
| node_affinity | smallint | Identifies the memory node to which this connection has affinity. Is not nullable. |
| num_reads | int | Number of byte reads that have occurred over this connection. Is nullable. |
| num_writes | int | Number of byte writes that have occurred over this connection. Is nullable. |
| last_read | datetime | Timestamp when last read occurred over this connection. Is nullable. |
| last_write | datetime | Timestamp when last write occurred over this connection. Not Is nullable. |
| net_packet_size | int | Network packet size used for information and data transfer. Is nullable. |
| client_net_address | varchar(48) | Host address of the client connecting to this server. Is nullable.
Prior to V12 in Azure SQL Database, this column always returns NULL. |
| client_tcp_port | int | Port number on the client computer that is associated with this connection. Is nullable.
In Azure SQL Database, this column always returns NULL. |
| local_net_address | varchar(48) | Represents the IP address on the server that this connection targeted. Available only for connections using the TCP transport provider. Is nullable.
In Azure SQL Database, this column always returns NULL. |
| local_tcp_port | int | Represents the server TCP port that this connection targeted if it were a connection using the TCP transport. Is nullable.
In Azure SQL Database, this column always returns NULL. |
| connection_id | uniqueidentifier | Identifies each connection uniquely. Is not nullable. |
| parent_connection_id | uniqueidentifier | Identifies the primary connection that the MARS session is using. Is nullable. |
| most_recent_sql_handle | varbinary(64) | The SQL handle of the last request executed on this connection. The most_recent_sql_handle column is always in sync with the most_recent_session_id column. Is nullable. |
| pdw_node_id | int | Applies to: Azure SQL Data Warehouse, Parallel Data Warehouse
The identifier for the node that this distribution is on. |
Permissions
On SQL Server, requires VIEW SERVER STATE permission.
On SQL Database Premium Tiers, requires the VIEW DATABASE STATE permission in the database. On SQL Database Standard and Basic Tiers, requires the Server admin or an Azure Active Directory admin account.
Physical Joins
Relationship Cardinalities
| dm_exec_sessions.session_id | dm_exec_connections.session_id | One-to-one |
| dm_exec_requests.connection_id | dm_exec_connections.connection_id | Many to one |
| dm_broker_connections.connection_id | dm_exec_connections.connection_id | One to one |
Examples
Typical query to gather information about a queries own connection.
SQLCopy
SELECT
c.session_id, c.net_transport, c.encrypt_option,
c.auth_scheme, s.host_name, s.program_name,
s.client_interface_name, s.login_name, s.nt_domain,
s.nt_user_name, s.original_login_name, c.connect_time,
s.login_time
FROM sys.dm_exec_connections AS c
JOIN sys.dm_exec_sessions AS s
ON c.session_id = s.session_id
WHERE c.session_id = @@SPID;
See Also
Execution Related Dynamic Management Views and Functions (Transact-SQL)
原文地址：https://www.cnblogs.com/jinanxiaolaohu/p/11451592.html