
Explanation:

Step 1: ALTER EVENT SESSION Contoso1 ON SERVER
Step 2: ADD EVENT ...
Step 3: (ACTION ...
Step 4: WHERE...
Step 5: ) GO
Example: To start an Extended Events sessions in order to trap SQL Server errors with severity greater than 10,just run the following script:
CREATE EVENT SESSION [error_trap] ON SERVER
ADD EVENT sqlserver.error_reported
(
ACTION
(package0.collect_system_time,package0.last_error,sqlserver.client_app_name,sqlserver.c lient_hostname,sqlserver.database_id,sqlserver.database_name,sqlserver.nt_username, sqlserver.plan_handle,sqlserver.query_hash,sqlserver.session_id,sqlserver.sql_text,sqlser ver.tsql_frame,sqlserver.tsql_stack,sqlserver.username)
WHERE ([severity]>10)
)
ADD TARGET package0.event_file
(
SET filename=N'D:\Program Files\Microsoft SQL
Server\MSSQL11.MSSQLSERVER\MSSQL\XEvents\error_trap.xel'
)
WITH
(
STARTUP_STATE=OFF
)
GO
References: