sql.Append("SELECT  * FROM FixThing");

  sql.Append(" AND fixingDate BETWEEN ");
            sql.Append(" 'fixQsdate=@fixQsdate'");
            sql.Append(" AND");
            sql.Append(" 'fixJsdate=@fixJsdate'");

SqlParameter[] Param = new SqlParameter[] { 
             new SqlParameter("@fixQsdate",SqlDbType.VarChar,50),
            new SqlParameter("@fixJsdate",SqlDbType.VarChar,50),
            };
                              
             Param[0].Value = fixthingdata.fixQsdate;
            Param[].Value = fixthingdata.fixJsdate;

这样查询时老是报错， 字符串向dateTime转化失败。。。 求高手。。