Question

如何在Entity Framework中编写参数化的原始sql查询？我尝试了以下内容：

string dateQueryString = String.Join(",", chartModelData.GetFormattedDateList());
//Dates returned in format of 20140402,20140506,20140704

const string selectQuery = 
    @"SELECT 
         MAX(DATA_SEQ) AS MaxSeq, MIN(DATA_SEQ) AS MinSeq, COUNT(1) AS TotSampleCnt
      FROM SPCDATA_TB
      WHERE DATA_WDATE IN @DateParam  
      AND LINE_CODE = @LineCode
      AND MODEL_NO = @ModelNumber
      AND LOT_NO = @LotNumber
      AND EQUIP_NO LIKE @EquipNumber";

SPCDataSeqCntInfo dataSeqCntInfo = _dbContext.Database.SqlQuery<SPCDataSeqCntInfo>(
      selectQuery,
      new SqlParameter("@DateParam",   dateQueryString),
      new SqlParameter("@LineCode",    chartModelData.LineCode),
      new SqlParameter("@ModelNumber", chartModelData.ModelNum),
      new SqlParameter("@EquipNumber", equipmentNumber),
      new SqlParameter("@LotNumber",   chartModelData.LotNum)
  ).SingleOrDefault() ?? new SPCDataSeqCntInfo();

但正如预期的那样，它会在DateParam上抛出一个错误，因为它期望一个值。

Answer 1

这不是特定于实体框架的问题，您可以通过动态生成自己的参数名来解决它。

var parameters = new List<SqlParameter> {
    new SqlParameter("@DateParam", dateQueryString),
    new SqlParameter("@LineCode", chartModelData.LineCode),
    new SqlParameter("@ModelNumber", chartModelData.ModelNum),
    new SqlParameter("@EquipNumber", equipmentNumber),
    new SqlParameter("@LotNumber", chartModelData.LotNum)   
};

var dateParameters = chartModelData
    .GetFormattedDateList()
    .Select((date, index) => new SqlParameter("@date" + index, date));

parameters.AddRange(dateParameters);

var inValues = string.Join(", ", dateParameters.Select(p => p.ParameterName));

var query = @"SELECT MAX(DATA_SEQ) AS MaxSeq, 
   MIN(DATA_SEQ) AS MinSeq, 
   COUNT(1) AS TotSampleCnt
   FROM SPCDATA_TB
   WHERE DATA_WDATE IN (" + inValues + @")  
   AND LINE_CODE = @LineCode
   AND MODEL_NO = @ModelNumber
   AND LOT_NO = @LotNumber
   AND EQUIP_NO LIKE @EquipNumber";

var myResult = _dbContext.Database
    .SqlQuery<SPCDataSeqCntInfo>(query, parameters.ToArray());

发送到SQL-Server的结果查询如下所示：

SELECT 
   MAX(DATA_SEQ) AS MaxSeq, 
   MIN(DATA_SEQ) AS MinSeq, 
   COUNT(1) AS TotSampleCnt
FROM SPCDATA_TB
WHERE DATA_WDATE IN (@date0, @date1, @date2)  
AND LINE_CODE = @LineCode
AND MODEL_NO = @ModelNumber
AND LOT_NO = @LotNumber
AND EQUIP_NO LIKE @EquipNumber

通常，您希望在编写查询时避免执行字符串操作，但是，我相信这个示例在sql-injection中是安全的。

Answer 2

以下是在SQL中编写查询的方法。

select *
    from MyTable
    where dateColumn in ('2014-01-01', '2014-02-01', '2014-03-01')

因此，除了必须用括号完全分隔这个字符串之外，我们不会指望。

var dateQueryString = string.Join(",", chartModelData.GetFormattedDateList());
// Dates shall be returned as DateTime.ToShortDateTimeString() as follows:
// '2014-01-01', '2014-02-01', '2014-03-01'

然后只留下用括号括起来。

var sql = @"select max(data_seq)    as MaxSeq
                    , min(data_seq) as MinSeq
                    , count(1)      as TotSampleCnt
                from spcdata_tb
                where data_wadate in (@DateParam)
                    and line_code  =  @LineCode
                    and model_no   =  @ModelNumber
                    and lot_no     =  @LotNumber
                    and equip_no like @EquipNumber";

为每个命名参数提供参数值，然后瞧！这应该做到！

Answer 3

我会写一个存储过程，而不是接受你的参数，然后将proc添加到你的edmx。

然后，在edmx中 - ＆gt;模型浏览器 - ＆gt;功能导入 - ＆gt; ...将存储过程的返回类型更改为SPCDataSeqCntInfo。

实体框架将负责传递您的参数。

e.g。

public static List<SPCDataSeqCntInfo> GetSPCDataSeqCntInfo(DateTime dateParam, string lineCode, int modelNum, int equipmentNumber, int lotNum)
{
    using (var db = new NameOfMyEntites())
    {
        return db.sp_GetSPCDataSeqCntInfo(dateParam, lineCode, modelNum, equipmentNumber, lotNum).ToList();
    }
}

如何在Entity Framework中编写参数化的原始sql查询

3 个答案: