C#的float型，竟然与SQL中float型不对应

最新推荐文章于 2022-03-08 17:07:53 发布

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最新推荐文章于 2022-03-08 17:07:53 发布

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文章标签：数据库 c/c++ c#

本文介绍了SQL中的数据类型与C#中的对应类型，特别指出SQL中的float类型在C#中应映射为double而非float。文章通过一个具体的转换函数示例，帮助开发者正确理解和使用不同类型之间的转换。

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使用NBearMapping做测试，才发现SQL中的float不能被自动Map到实体类型为float字段中。
搜索了一下，才发现SQL中的float对应到C#的double，我晕了。
http://www.cnblogs.com/xkforever/archive/2007/04/27/729858.html

        /// <summary>
         /// 数据库中与C#中的数据类型对照
         /// </summary>
         /// <param name="type"></param>
         /// <returns></returns>
         private string ChangeToCSharpType( string type)
        {
             string reval = string .Empty;
             switch (type.ToLower())
            {
                 case " int " :
                    reval = " Int32 " ;
                     break ;
                 case " text " :
                    reval = " String " ;
                     break ;
                 case " bigint " :
                    reval = " Int64 " ;
                     break ;
                 case " binary " :
                    reval = " System.Byte[] " ;
                     break ;
                 case " bit " :
                    reval = " Boolean " ;
                     break ;
                 case " char " :
                    reval = " String " ;
                     break ;
                 case " datetime " :
                    reval = " System.DateTime " ;
                     break ;
                 case " decimal " :
                    reval = " System.Decimal " ;
                     break ;
                 case " float " :
                    reval = " System.Double " ;
                     break ;
                 case " image " :
                    reval = " System.Byte[] " ;
                     break ;
                 case " money " :
                    reval = " System.Decimal " ;
                     break ;
                 case " nchar " :
                    reval = " String " ;
                     break ;
                 case " ntext " :
                    reval = " String " ;
                     break ;
                 case " numeric " :
                    reval = " System.Decimal " ;
                     break ;
                 case " nvarchar " :
                    reval = " String " ;
                     break ;
                 case " real " :
                    reval = " System.Single " ;
                     break ;
                 case " smalldatetime " :
                    reval = " System.DateTime " ;
                     break ;
                 case " smallint " :
                    reval = " Int16 " ;
                     break ;
                 case " smallmoney " :
                    reval = " System.Decimal " ;
                     break ;
                 case " timestamp " :
                    reval = " System.DateTime " ;
                     break ;
                 case " tinyint " :
                    reval = " System.Byte " ;
                     break ;
                 case " uniqueidentifier " :
                    reval = " System.Guid " ;
                     break ;
                 case " varbinary " :
                    reval = " System.Byte[] " ;
                     break ;
                 case " varchar " :
                    reval = " String " ;
                     break ;
                 case " Variant " :
                    reval = " Object " ;
                     break ;
                 default :
                    reval = " String " ;
                     break ;
            }
             return reval;
        }

唉，基础不好，更重要的是脑子的内存坏了，一睡醒就丢失资料。