Keywords + NULL Columns

Moved keywords that can also be IDs, added NULL as a column element as "select null as column_name" is valid.

Author: ShortIsLong

sql/tsql/TSqlLexer.g4

@@ -105,7 +105,6 @@ CURRENT_TIMESTAMP:                     'CURRENT_TIMESTAMP';
 CURRENT_USER:                          'CURRENT_USER';
 CURSOR:                                'CURSOR';
 CYCLE:                                 'CYCLE';
-DATA:                                  'DATA';
 DATA_COMPRESSION:                      'DATA_COMPRESSION';
 DATA_SOURCE:                           'DATA_SOURCE';
 DATABASE:                              'DATABASE';
@@ -328,13 +327,11 @@ SAVE:                                  'SAVE';
 SCHEDULER:                             'SCHEDULER';
 SCHEMA:                                'SCHEMA';
 SCHEME:                                'SCHEME';
-SECURITY:                              'SECURITY';
 SECURITYAUDIT:                         'SECURITYAUDIT';
 SELECT:                                'SELECT';
 SEMANTICKEYPHRASETABLE:                'SEMANTICKEYPHRASETABLE';
 SEMANTICSIMILARITYDETAILSTABLE:        'SEMANTICSIMILARITYDETAILSTABLE';
 SEMANTICSIMILARITYTABLE:               'SEMANTICSIMILARITYTABLE';
-SEQUENCE:                              'SEQUENCE';
 SERVER:                                'SERVER';
 SERVICE:                               'SERVICE';
 SERVICE_BROKER:                        'SERVICE_BROKER';
@@ -364,7 +361,6 @@ STOP:                                  'STOP';
 STOPPED:                               'STOPPED';
 STOP_ON_ERROR:                         'STOP_ON_ERROR';
 SUPPORTED:                             'SUPPORTED';
-SYSTEM:                                'SYSTEM';
 SYSTEM_USER:                           'SYSTEM_USER';
 TABLE:                                 'TABLE';
 TABLESAMPLE:                           'TABLESAMPLE';
@@ -485,6 +481,7 @@ CREDENTIAL:                            'CREDENTIAL';
 CRYPTOGRAPHIC:                         'CRYPTOGRAPHIC';
 CURSOR_CLOSE_ON_COMMIT:                'CURSOR_CLOSE_ON_COMMIT';
 CURSOR_DEFAULT:                        'CURSOR_DEFAULT';
+DATA:                                  'DATA';
 DATE_CORRELATION_OPTIMIZATION:         'DATE_CORRELATION_OPTIMIZATION';
 DATEADD:                               'DATEADD';
 DATEDIFF:                              'DATEDIFF';
@@ -740,12 +737,14 @@ SECONDARY_ONLY:                        'SECONDARY_ONLY';
 SECONDARY_ROLE:                        'SECONDARY_ROLE';
 SECONDS:                               'SECONDS';
 SECRET:                                'SECRET';
+SECURITY:                              'SECURITY';
 SECURITY_LOG:                          'SECURITY_LOG';
 SEEDING_MODE:                          'SEEDING_MODE';
 SELF:                                  'SELF';
 SEMI_SENSITIVE:                        'SEMI_SENSITIVE';
 SEND:                                  'SEND';
 SENT:                                  'SENT';
+SEQUENCE:                              'SEQUENCE';
 SERIALIZABLE:                          'SERIALIZABLE';
 SESSION_TIMEOUT:                       'SESSION_TIMEOUT';
 SETERROR:                              'SETERROR';
@@ -776,6 +775,7 @@ SUSPEND:                               'SUSPEND';
 SYMMETRIC:                             'SYMMETRIC';
 SYNCHRONOUS_COMMIT:                    'SYNCHRONOUS_COMMIT';
 SYNONYM:                               'SYNONYM';
+SYSTEM:                                'SYSTEM';
 TAKE:                                  'TAKE';
 TARGET_RECOVERY_TIME:                  'TARGET_RECOVERY_TIME';
 TB:                                    'TB';

sql/tsql/TSqlParser.g4

@@ -3041,7 +3041,7 @@ asterisk
     ;
 
 column_elem
-    : (table_name '.')? (column_name=id | '$' IDENTITY | '$' ROWGUID) as_column_alias?
+    : (table_name '.')? (column_name=id | '$' IDENTITY | '$' ROWGUID | NULL) as_column_alias?
     ;
 
 udt_elem
@@ -3703,6 +3703,7 @@ simple_id
     | CRYPTOGRAPHIC
     | CURSOR_CLOSE_ON_COMMIT
     | CURSOR_DEFAULT
+    | DATA
     | DATA_COMPRESSION
     | DATE_CORRELATION_OPTIMIZATION
     | DATEADD
@@ -3971,12 +3972,14 @@ simple_id
     | SECONDARY_ROLE
     | SECONDS
     | SECRET
+    | SECURITY
     | SECURITY_LOG
     | SEEDING_MODE
     | SELF
     | SEMI_SENSITIVE
     | SEND
     | SENT
+    | SEQUENCE
     | SERIALIZABLE
     | SERVER
     | SESSION_TIMEOUT
@@ -4012,6 +4015,7 @@ simple_id
     | SYMMETRIC
     | SYNCHRONOUS_COMMIT
     | SYNONYM
+    | SYSTEM
     | TAKE
     | TARGET
     | TARGET_RECOVERY_TIME