Question

sql c# 出现错误字符串向时间转换失败！！

string sql = string.Format("select * from certificateManage where certificateNo ='{0}'or personName = '{1}' or startCertificateDate ='convert(varchar(12) , {2}, 111 )' or" +
" levelName = '{3}' or healthlevelName = '{4}' or categoryProtectName = '{5}'",CFManage.CertificateNo,CFManage.PersonName,CFManage.StartCertificateDate,CFManage.LevelName,CFManage.HealthlevelName,CFManage.CategoryProtectName);

Answer 1

单引号内的convert只会当做字符串来处理，而不是函数。
做如下修改：
string sql = string.Format("select * from certificateManage where certificateNo ='{0}'or personName = '{1}' or startCertificateDate ='{2}' or" +
" levelName = '{3}' or healthlevelName = '{4}' or categoryProtectName = '{5}'",CFManage.CertificateNo,CFManage.PersonName,CFManage.StartCertificateDate.ToString("yyyy-MM-dd"),CFManage.LevelName,CFManage.HealthlevelName,CFManage.CategoryProtectName);

Answer 2

你做个判断处理下，如果这个字符串不是时间格式的，就赋值为null 就可以了。