使用like查询text类型字段

最新推荐文章于 2025-07-11 17:18:35 发布

18790970257

最新推荐文章于 2025-07-11 17:18:35 发布

阅读量527

点赞数

CC 4.0 BY-SA版权

文章标签：数据库

原文链接：http://www.cnblogs.com/cuihongyu3503319/p/5053863.html

本文介绍了如何使用SQL中的Like操作符来查询Text类型的字段，并通过具体的C#代码示例展示了如何实现模糊匹配。此外，还提供了一种方法来查找未被特定用户阅读的消息。

使用like查询text类型字段

        public bool Exists(GetReadType GRT, ClientMessageGetRead TypeID, string MessageID, string UserID)
        {
            int ThisGRT = Convert.ToInt32(GRT);
            int ThisTypeID = Convert.ToInt32(TypeID);
            string strSql = @"
                            select 
                                count(1) 
                            from 
                                Client_Message_GetRead 
                            where 
                                GetRead = @GetRead 
                            and 
                                TypeID = @TypeID 
                            and 
                                MessageID like '%'+@MessageID+'%' 
                            and 
                                UserID = @UserID
                            ";

            SqlParameter[] parameters = {
                    new SqlParameter("@GetRead", SqlDbType.Int,4),
                    new SqlParameter("@TypeID", SqlDbType.Int,4),
                    new SqlParameter("@MessageID", SqlDbType.Char,36),
                    new SqlParameter("@UserID", SqlDbType.Char,36)
                                        };
            parameters[0].Value = ThisGRT;
            parameters[1].Value = ThisTypeID;
            parameters[2].Value = MessageID;
            parameters[3].Value = UserID;

            return DbHelperSQL.Exists(strSql.ToString(), parameters);
        }


        public DataSet NotExists1(GetReadType GRT, string CompanyID, string UserID)
        {
            int ThisGRT = Convert.ToInt32(GRT);
            int ThisTypeID = Convert.ToInt32(ClientMessageGetRead.公益团体消息);
            string strSql = @"
                            select 
                                *
                            from 
                                Company_Company_Message
                            where 
                                CompanyID = @CompanyID
                            and
                            (
                            select 
                                top 1 MessageID 
                            from 
                                Client_Message_GetRead 
                            where 
                                GetRead = @GetRead
                            and 
                                TypeID = @TypeID
                            and 
                                UserID = @UserID
                            )
                            not like '%'+MessageID +'%'
                            ";

            SqlParameter[] parameters = {
                    new SqlParameter("@GetRead", SqlDbType.Int,4),
                    new SqlParameter("@TypeID", SqlDbType.Int,4),
                    new SqlParameter("@CompanyID", SqlDbType.Char,36),
                    new SqlParameter("@UserID", SqlDbType.Char,36)
                                        };
            parameters[0].Value = ThisGRT;
            parameters[1].Value = ThisTypeID;
            parameters[2].Value = CompanyID;
            parameters[3].Value = UserID;

            return DbHelperSQL.Query(strSql.ToString(), parameters);
        }