如何在C＃中动态创建FileUploads的查询？

Posted 2021-05-06

如何减少下面代码中的代码冗余？我正在尝试根据上传的动态附件数量构建查询。用户最多可以添加5个附件。程序需要根据输入附件的数量检查查询并构建查询。示例代码如下所示：

            StringBuilder sbView5SaveQuery = new StringBuilder();
            sbView5SaveQuery.Append("update Master set ");

            if (FileUpload1.HasFile)
            {
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("SupportDoc1 = @SupportDoc1");
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("CanPublishDoc1 = @CanPublishDoc1");
                sbView5SaveQuery.Append(" ");
            }

            if (FileUpload2.HasFile)
            {
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("SupportDoc2 = @SupportDoc2");
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("CanPublishDoc2 = @CanPublishDoc2");
                sbView5SaveQuery.Append(" ");
            }
            if (FileUpload3.HasFile)
            {
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("SupportDoc3 = @SupportDoc3");
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("CanPublishDoc3 = @CanPublishDoc3");
                sbView5SaveQuery.Append(" "); ;
            }
            if (FileUpload4.HasFile)
            {
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("SupportDoc4 = @SupportDoc4");
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("CanPublishDoc4 = @CanPublishDoc4");
                sbView5SaveQuery.Append(" ");
            }
            if (FileUpload5.HasFile)
            {
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("SupportDoc5 = @SupportDoc5");
                sbView5SaveQuery.Append(",");
                sbView5SaveQuery.Append("CanPublishDoc5 = @CanPublishDoc5");
                sbView5SaveQuery.Append(" ");
            }
            sbView5SaveQuery.Append("where MasterID = @MasterID");

答案

在类中创建一个方法并将值传递给它，而不是重复每次上传的代码：

public class MyClass 
{
    private StringBuilder sbView5SaveQuery;

    private void BuildQuery(string supportDoc, string canPublishDoc)
    {
        sbView5SaveQuery.Append(",");
        sbView5SaveQuery.Append(supportDoc + " = @" + supportDoc);
        sbView5SaveQuery.Append(",");
        sbView5SaveQuery.Append(canPublishDoc + " = @" + canPublishDoc);
        sbView5SaveQuery.Append(" ");
    }

    public string MyMethod()
    {
        sbView5SaveQuery = new StringBuilder();
        sbView5SaveQuery.Append("update Master set ");

        if (FileUpload1.HasFile)
        {
            BuildQuery("SupportDoc1", "CanPublishDoc1");
        }

        if (FileUpload2.HasFile)
        {
             BuildQuery("SupportDoc2", "CanPublishDoc2");
        }

        // and so one...

        return sbView5SaveQuery.ToString();
    }
}