Merge pull request #1194 from BYHAM/patch-50

CREATE TRIGGER, formatting

Author: v-thepet

docs/t-sql/statements/create-trigger-transact-sql.md

@@ -2,7 +2,7 @@
 title: "CREATE TRIGGER (Transact-SQL) | Microsoft Docs"
 ms.custom: 
   - "SQL2016_New_Updated"
-ms.date: "12/16/2016"
+ms.date: "04/11/2017"
 ms.prod: "sql-non-specified"
 ms.reviewer: ""
 ms.suite: ""
@@ -52,7 +52,6 @@ manager: "jhubbard"
 ## Syntax  
 
 ```  
-  
 -- SQL Server Syntax  
 -- Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger)  
   
@@ -76,7 +75,8 @@ AS { sql_statement  [ ; ] [ ,...n ] | EXTERNAL NAME <method specifier [ ; ] > }
 
 ```  
 -- SQL Server Syntax  
--- Trigger on an INSERT, UPDATE, or DELETE statement to a table (DML Trigger on memory-optimized tables)  
+-- Trigger on an INSERT, UPDATE, or DELETE statement to a 
+-- table (DML Trigger on memory-optimized tables)  
   
 CREATE [ OR ALTER ] TRIGGER [ schema_name . ]trigger_name   
 ON { table }   
@@ -93,7 +93,8 @@ AS { sql_statement  [ ; ] [ ,...n ] }
 ```  
 
 ```  
--- Trigger on a CREATE, ALTER, DROP, GRANT, DENY, REVOKE or UPDATE statement (DDL Trigger)  
+-- Trigger on a CREATE, ALTER, DROP, GRANT, DENY, 
+-- REVOKE or UPDATE statement (DDL Trigger)  
   
 CREATE [ OR ALTER ] TRIGGER trigger_name   
 ON { ALL SERVER | DATABASE }   
@@ -142,7 +143,8 @@ ON { table | view }
 
 ```  
 -- Windows Azure SQL Database Syntax  
--- Trigger on a CREATE, ALTER, DROP, GRANT, DENY, REVOKE, or UPDATE STATISTICS statement (DDL Trigger)   
+-- Trigger on a CREATE, ALTER, DROP, GRANT, DENY, 
+-- REVOKE, or UPDATE STATISTICS statement (DDL Trigger)   
   
 CREATE [ OR ALTER ] TRIGGER trigger_name   
 ON { DATABASE }   
@@ -156,9 +158,7 @@ AS { sql_statement  [ ; ] [ ,...n ]  [ ; ] }
 
 ## Arguments
 OR ALTER  
- ||  
-|-|  
-|**Applies to**: Azure [!INCLUDE[ssSDS](../../includes/sssds-md.md)], [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] (starting with [!INCLUDE[ssSQL15](../../includes/sssql15-md.md)] SP1).| 
+ **Applies to**: Azure [!INCLUDE[ssSDS](../../includes/sssds-md.md)], [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] (starting with [!INCLUDE[ssSQL15](../../includes/sssql15-md.md)] SP1). 
 
  Conditionally alters the trigger only if it already exists. 
 
@@ -175,16 +175,12 @@ OR ALTER
  Applies the scope of a DDL trigger to the current database. If specified, the trigger fires whenever *event_type* or *event_group* occurs in the current database.  
 
  ALL SERVER  
- ||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+ **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
  Applies the scope of a DDL or logon trigger to the current server. If specified, the trigger fires whenever *event_type* or *event_group* occurs anywhere in the current server.  
 
  WITH ENCRYPTION  
- ||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+ **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
  Obfuscates the text of the CREATE TRIGGER statement. Using WITH ENCRYPTION prevents the trigger from being published as part of [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] replication. WITH ENCRYPTION cannot be specified for CLR triggers.  
 
@@ -225,9 +221,7 @@ OR ALTER
  For INSTEAD OF triggers, the DELETE option is not allowed on tables that have a referential relationship specifying a cascade action ON DELETE. Similarly, the UPDATE option is not allowed on tables that have a referential relationship specifying a cascade action ON UPDATE.  
 
  WITH APPEND  
- ||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssKilimanjaro](../../includes/sskilimanjaro-md.md)].|  
+ **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssKilimanjaro](../../includes/sskilimanjaro-md.md)].  
 
  Specifies that an additional trigger of an existing type should be added. WITH APPEND cannot be used with INSTEAD OF triggers or if AFTER trigger is explicitly stated. WITH APPEND can be used only when FOR is specified, without INSTEAD OF or AFTER, for backward compatibility reasons. WITH APPEND cannot be specified if EXTERNAL NAME is specified (that is, if the trigger is a CLR trigger).  
 
@@ -240,9 +234,7 @@ OR ALTER
  After the CREATE TRIGGER has finished running, *event_group* also acts as a macro by adding the event types it covers to the sys.trigger_events catalog view.  
 
  NOT FOR REPLICATION  
- ||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+ **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
  Indicates that the trigger should not be executed when a replication agent modifies the table that is involved in the trigger.  
 
@@ -271,18 +263,14 @@ SELECT * FROM deleted;
  For triggers on memory-optimized tables, the only *sql_statement* allowed at the top level is an ATOMIC block. The T-SQL allowed inside the ATOMIC block is limited by the T-SQL allowed inside native procs.  
 
  < method_specifier >  
- ||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+ **Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
  For a CLR trigger, specifies the method of an assembly to bind with the trigger. The method must take no arguments and return void. *class_name* must be a valid [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] identifier and must exist as a class in the assembly with assembly visibility. If the class has a namespace-qualified name that uses '.' to separate namespace parts, the class name must be delimited by using [ ] or " " delimiters. The class cannot be a nested class.  
 
 > [!NOTE]  
 >  By default, the ability of [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] to run CLR code is off. You can create, modify, and drop database objects that reference managed code modules, but these references will not execute in an instance of [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] unless the [clr enabled Option](../../database-engine/configure-windows/clr-enabled-server-configuration-option.md) is enabled by using [sp_configure](../../relational-databases/system-stored-procedures/sp-configure-transact-sql.md).  
   
-## Remarks  
-  
-## DML Triggers  
+## Remarks DML Triggers  
  DML triggers are frequently used for enforcing business rules and data integrity. [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] provides declarative referential integrity (DRI) through the ALTER TABLE and CREATE TABLE statements. However, DRI does not provide cross-database referential integrity. Referential integrity refers to the rules about the relationships between the primary and foreign keys of tables. To enforce referential integrity, use the PRIMARY KEY and FOREIGN KEY constraints in ALTER TABLE and CREATE TABLE. If constraints exist on the trigger table, they are checked after the INSTEAD OF trigger execution and before the AFTER trigger execution. If the constraints are violated, the INSTEAD OF trigger actions are rolled back and the AFTER trigger is not fired.  
 
  The first and last AFTER triggers to be executed on a table can be specified by using sp_settriggerorder. Only one first and one last AFTER trigger for each INSERT, UPDATE, and DELETE operation can be specified on a table. If there are other AFTER triggers on the same table, they are randomly executed.  
@@ -337,7 +325,7 @@ SELECT * FROM deleted;
 > [!NOTE]  
 >  Because [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] does not support user-defined triggers on system tables, we recommend that you do not create user-defined triggers on system tables.  
   
-## DDL Triggers  
+## Remarks DDL Triggers  
  DDL triggers, like standard triggers, execute stored procedures in response to an event. But unlike standard triggers, they do not execute in response to UPDATE, INSERT, or DELETE statements on a table or view. Instead, they primarily execute in response to data definition language (DDL) statements. These include CREATE, ALTER, DROP, GRANT, DENY, REVOKE, and UPDATE STATISTICS statements. Certain system stored procedures that perform DDL-like operations can also fire DDL triggers.  
 
 > [!IMPORTANT]  
@@ -444,8 +432,8 @@ GO
  The following example creates a DML trigger in the AdventureWorks2012 database. This trigger checks to make sure the credit rating for the vendor is good (not 5) when an attempt is made to insert a new purchase order into the `PurchaseOrderHeader` table. To obtain the credit rating of the vendor, the `Vendor` table must be referenced. If the credit rating is too low, a message is displayed and the insertion does not execute.  
 
 ```  
--- This trigger prevents a row from being inserted in the Purchasing.PurchaseOrderHeader table  
--- when the credit rating of the specified vendor is set to 5 (below average).  
+-- This trigger prevents a row from being inserted in the Purchasing.PurchaseOrderHeader 
+-- table when the credit rating of the specified vendor is set to 5 (below average).  
   
 CREATE TRIGGER Purchasing.LowCredit ON Purchasing.PurchaseOrderHeader  
 AFTER INSERT  
@@ -506,9 +494,7 @@ GO
 ### E. Using a server-scoped DDL trigger  
  The following example uses a DDL trigger to print a message if any CREATE DATABASE event occurs on the current server instance, and uses the `EVENTDATA` function to retrieve the text of the corresponding [!INCLUDE[tsql](../../includes/tsql-md.md)] statement. For more examples that use EVENTDATA in DDL triggers, see [Use the EVENTDATA Function](../../relational-databases/triggers/use-the-eventdata-function.md).  
 
-||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
 ```  
 CREATE TRIGGER ddl_trig_database   
@@ -526,9 +512,7 @@ GO
 ### F. Using a logon trigger  
  The following logon trigger example denies an attempt to log in to [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] as a member of the *login_test* login if there are already three user sessions running under that login.  
 
-||  
-|-|  
-|**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].|  
+**Applies to**: [!INCLUDE[ssKatmai](../../includes/sskatmai-md.md)] through [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)].  
 
 ```  
 USE master;