delphi - 从 delphi 7 迁移到 delphi XE4 时出现 TSQLDataset 错误

Question

TSQLDataSet我的 Delphi 7 应用程序中有以下内容。它从表 MyTable 中获取 2 个字段（ID 和名称）。

object SQLDataSet: TSQLDataSet
    GetMetadata = False
    CommandText = 'select * from MyTable'
    MaxBlobSize = -1
    Params = <>
    SQLConnection = mySQLConnection

    object SQLDataSetID: TIntegerField
      FieldName = 'ID'
      ProviderFlags = [pfInUpdate, pfInWhere, pfInKey]
      Required = True
    end
    object SQLDataSetNAME: TStringField
      FieldName = 'NAME'
      Required = True
      Size = 50
    end
end

当我迁移到 Delphi XE4 时，出现以下错误：

class EDatabaseError with message 'SQLDataSet: Type mismatch for field 'NAME', expecting: String actual:WideString'

这个问题的可能原因是什么，我应该如何摆脱它？

注意：我正在使用firebird 2.5.2.

Answer 1

更改TStringField为TWideTStringfield

object SQLDataSet: TSQLDataSet
    GetMetadata = False
    CommandText = 'select * from MyTable'
    MaxBlobSize = -1
    Params = <>
    SQLConnection = mySQLConnection

    object SQLDataSetID: TIntegerField
      FieldName = 'ID'
      ProviderFlags = [pfInUpdate, pfInWhere, pfInKey]
      Required = True
    end
    object SQLDataSetNAME: **TWideStringField**
      FieldName = 'NAME'
      Required = True
      Size = 50
    end
end