merge abstract method
      
Future<bool> 
merge(
    
    
- List<Map< sourceData, {String, dynamic> >
- required List<String> matchOn,
- ConflictAction whenMatched = ConflictAction.update,
- ConflictAction whenNotMatched = ConflictAction.ignore,
- ConflictAction? whenNotMatchedBySource,
- List<String> ? updateColumns,
- List<String> ? insertColumns,
- Map<String, dynamic> ? additionalValues,
Implementation
Future<bool> merge(
  List<Map<String, dynamic>> sourceData, {
  required List<String> matchOn,
  ConflictAction whenMatched = ConflictAction.update,
  ConflictAction whenNotMatched = ConflictAction.ignore,
  ConflictAction? whenNotMatchedBySource,
  List<String>? updateColumns,
  List<String>? insertColumns,
  Map<String, dynamic>? additionalValues,
});