anchor.diff:                            | expr ( ',' expr )*
                             )? 
                         ')'
  -                    | ( database_name '.' )? table_name )
  +                    | table_name )
    | ( ( K_NOT )? K_EXISTS )? '(' select_stmt ')'
    | K_CASE expr? ( K_WHEN expr K_THEN expr )+ ( K_ELSE expr )? K_END
    | raise_function
  
positive.code:  : any_name
   ;
  
  database_name
   : any_name
   ;
  
  table_name 
   : IDENTIFIER
   ;
  
negative.code:  ;
  
  alter_table_stmt
   : K_ALTER K_TABLE table_name
     ( K_RENAME K_TO new_table_name
     | K_ADD K_COLUMN? column_def
     )
   ;
  
  analyze_stmt
   : K_ANALYZE table_or_index_name
   ;
  
  create_index_stmt
   : K_CREATE K_UNIQUE? K_INDEX ( K_IF K_NOT K_EXISTS )?
     index_name K_ON table_name '(' indexed_column ( ',' indexed_column )* ')'
     ( K_WHERE expr )?
   ;
  
  create_table_stmt
   : K_CREATE ( K_TEMP | K_TEMPORARY )? K_TABLE ( K_IF K_NOT K_EXISTS )?
     table_name
     ( '(' column_def ( ',' column_def )* ( ',' table_constraint )* ')' ( K_WITHOUT IDENTIFIER )?
     | K_AS select_stmt 
     )
  