Question

如何检查IsNullOrEmpty中的RawSQL。如果控制号和发送方ID都具有值，则检查两者的条件。如果单独拥有发送方ID，则像单独检查发送方ID的条件，如果它单独拥有controlnumber，就像仅检查controlnumber的条件一样。它显示类似

的错误

*附近的语法不正确

using (var context = new BSoftWEDIIContext())
                {

                    if (!string.IsNullOrEmpty(controlNumber))
                    {
                        controlNumber = "*" + controlNumber + "*";
                    }
                    if (!string.IsNullOrEmpty(senderNumber))
                    {
                        senderNumber = "*" + senderNumber + "*";
                    }

                    var fileDetail = context.FileDetails
                        .SqlQuery("select * from FileDetails where @" + controlNumber.ToString()
                        +" is not null OR CONVERT(varchar(max), RawData) like '%" + controlNumber.ToString() 
                        + "%' AND CONVERT(varchar(max), RawData) like '%" + senderNumber.ToString()+"%'").ToList();
                    matchedFileId = fileDetail?.Select(a => a.Id).ToList();

                }

Answer 1

您追加的*过多，结果查询无法正确构建。相应地检查条件：

using (var context = new BSoftWEDIIContext())
            {

                if (!string.IsNullOrEmpty(controlNumber))
                {
                    controlNumber = controlNumber;
                }
                if (!string.IsNullOrEmpty(senderNumber))
                {
                    senderNumber = senderNumber;
                }

                var fileDetail = context.FileDetails.SqlQuery("select * from FileDetails where " + controlNumber.ToString() + " is not null" + " OR CONVERT(varchar(max), RawData) like '%" + controlNumber.ToString() + "%' AND CONVERT(varchar(max), RawData) like '%" + senderNumber.ToString() + "%'").ToList();
                matchedFileId = fileDetail?.Select(a => a.Id).ToList();
            }

注意：此方法易于进行SQL注入，因此完全不建议使用。请通过以下链接阅读有关参数化查询和最佳做法的信息：

https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/ef/how-to-execute-a-parameterized-entity-sql-query-using-entitycommand

how to change sql statement to parameterized query?

如何在原始SQL中为表中未分配的值使用null或空值？

1 个答案: