anchor.diff:    const SequenceGenerator(this.name, {this.allocationSize, this.initialValue: 1, this.sequenceName, this.schema, this.catalog});
   }
   
  -/** For class: specifies the mapping of the result of a native SQL query.
  - * + [name] - the query result name use to associate with real Query.
  - * + [columns] - specifies the result set mapping to scalar values.
  - * + [entities] - specifies the result set mapping to entities.
  - */
  +/// For class: specifies the mapping of the result of a native SQL query.
  +/// + [name] - the query result name use to associate with real Query.
  +/// + [columns] - specifies the result set mapping to scalar values.
  +/// + [entities] - specifies the result set mapping to entities.
   //@Target(value:"TYPE")
   class SqlResultSetMapping {
     final String name;
  
positive.code:   const SecondaryTable(this.name, {this.schema, this.catalog, this.uniqueConstraints, this.pkJoinColumns});
  }
  
  /** For class: specifies multiple secndary tables for the entity class. */
  //@Target(value:"TYPE")
  class SecondaryTables {
    final List<SecondaryTable> tables;
  
negative.code:   const _Blob();
  }
  
  /// For field: defines a many-to-many association.
  /// + [mappedBy] - the feild that owns the relationship
  /// + [targetEntity] - the entity class that is the target of the association.
  /// + [fetch] - the fetch type; see [FetchType]
  /// + [cascade] - the operations specified here shall be cascaded to the
  /// other side; see [CascadeType]
  //@Target(vlaue="FIELD")
  class ManyToMany {
    final String mappedBy;
  