anchor.diff:      : columnName (ASC | DESC)?
       ;
   
  -columnNameGeneratedClause
  -    : columnNameGenerated DEFAULT simpleExpr (WITH VALUES)? COMMA_ columnNameGenerated
  -    ;
  -
  -columnNameGenerated
  +
  +generatedColumnNameClause
  +    : generatedColumnName DEFAULT simpleExpr (WITH VALUES)? COMMA_ generatedColumnName
  +    ;
  +
  +generatedColumnName
       : columnName dataTypeName_ GENERATED ALWAYS AS ROW (START | END)? HIDDEN_? (NOT NULL)? (CONSTRAINT ignoredIdentifier_)?
       ;
   
  
positive.code:     ;
  
  addColumnSpecification
      : (WITH (CHECK | NOCHECK))? ADD (alterColumnAddOption (COMMA_ alterColumnAddOption)* | (columnNameGeneratedClause COMMA_ periodClause| periodClause COMMA_ columnNameGeneratedClause))
      ;
  
  alterColumnAddOption
  
negative.code:     ;
  
  alterClause_
      : modifyColumnSpecification | addColumnSpecification | alterDrop | alterCheckConstraint | alterTrigger | alterSwitch | alterSet | alterTableTableOption | REBUILD
      ;
  
  
  