add alias for subquery grammar (#4588)

shardingsphere-sql-parser/shardingsphere-sql-parser-mysql/src/main/antlr4/imports/mysql/DMLStatement.g4

@@ -223,7 +223,7 @@ tableReference
     ;
 
 tableFactor
-    : tableName partitionNames_? (AS? alias)? indexHintList_? | subquery columnNames? | LP_ tableReferences RP_
+    : tableName partitionNames_? (AS? alias)? indexHintList_? | subquery AS? alias columnNames? | LP_ tableReferences RP_
     ;
 
 partitionNames_ 

shardingsphere-sql-parser/shardingsphere-sql-parser-oracle/src/main/antlr4/imports/oracle/DMLStatement.g4

@@ -149,7 +149,7 @@ tableReference
     ;
 
 tableFactor
-    : tableName (AS? alias)? | subquery columnNames? | LP_ tableReferences RP_
+    : tableName (AS? alias)? | subquery AS? alias columnNames? | LP_ tableReferences RP_
     ;
 
 joinedTable

shardingsphere-sql-parser/shardingsphere-sql-parser-postgresql/src/main/antlr4/imports/postgresql/DMLStatement.g4

@@ -125,7 +125,7 @@ tableReference
     ;
 
 tableFactor
-    : tableName (AS? alias)? | subquery columnNames? | LP_ tableReferences RP_
+    : tableName (AS? alias)? | subquery AS? alias columnNames? | LP_ tableReferences RP_
     ;
 
 joinedTable

shardingsphere-sql-parser/shardingsphere-sql-parser-postgresql/src/main/antlr4/imports/postgresql/Keyword.g4

@@ -550,4 +550,4 @@ NUMERIC
 
 TEXT
     : T E X T
-    ;
\ No newline at end of file
+    ;

shardingsphere-sql-parser/shardingsphere-sql-parser-sql92/src/main/antlr4/imports/sql92/DMLStatement.g4

@@ -121,7 +121,7 @@ tableReference
     ;
 
 tableFactor
-    : tableName (AS? alias)? | subquery columnNames? | LP_ tableReferences RP_
+    : tableName (AS? alias)? | subquery AS? alias columnNames? | LP_ tableReferences RP_
     ;
 
 joinedTable

shardingsphere-sql-parser/shardingsphere-sql-parser-sqlserver/src/main/antlr4/imports/sqlserver/DMLStatement.g4

@@ -121,7 +121,7 @@ tableReference
     ;
 
 tableFactor
-    : tableName (AS? alias)? | subquery columnNames? | LP_ tableReferences RP_
+    : tableName (AS? alias)? | subquery AS? alias columnNames? | LP_ tableReferences RP_
     ;
 
 joinedTable