asp.net将sql语句封装在类库中

将sql语句封装在cs中，通过类库的引用使用他的select、update、insert

源代码（cs）：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

//包括from、where、group by、order by...
namespace BLL
{//------------------------------------------------------------------------------------------------
    /// <summary>
    /// 构建 SQL 语句
    /// </summary>
    [Serializable]
    public class BuildSQL
    {

        #region 字段

        private int g_intStart;
        private int g_intRowCnt;
        private string g_strField;
        private string g_strFrom;
        private string g_strWhere;
        private string g_strOrderBy;
        private string g_strGroupBy;
        private string g_strOther;

        #endregion

        #region 属性

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 取得数据开始编号
        /// </summary>
        public int Start
        {
            get { return g_intStart; }
            set { g_intStart = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 取得记录数
        /// </summary>
        public int RowCnt
        {
            get { return g_intRowCnt; }
            set { g_intRowCnt = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 字段名
        /// </summary>
        public string Field
        {
            get { return g_strField; }
            set { g_strField = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 表名
        /// </summary>
        public string From
        {
            get { return g_strFrom; }
            set { g_strFrom = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 条件
        /// </summary>
        public string Where
        {
            get { return g_strWhere; }
            set { g_strWhere = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 排序
        /// </summary>
        public string OrderBy
        {
            get { return g_strOrderBy; }
            set { g_strOrderBy = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 分组
        /// </summary>
        public string GroupBy
        {
            get { return g_strGroupBy; }
            set { g_strGroupBy = value; }
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 其它
        /// </summary>
        public string Other
        {
            get { return g_strOther; }
            set { g_strOther = value; }
        }

        #endregion

        #region 方法

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        public BuildSQL()
        {
            g_strField = "*";
            g_strFrom = "";
            g_strWhere = "";
            g_strOrderBy = "";
            g_strGroupBy = "";
            g_strOther = "";
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strFrom">表名</param>
        public BuildSQL(string m_strFrom)
            : this()
        {
            g_strFrom = m_strFrom;
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strField">字段名</param>
        /// <param name="m_strFrom">表名</param>
        public BuildSQL(string m_strField, string m_strFrom)
            : this()
        {
            g_strField = m_strField;
            g_strFrom = m_strFrom;
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strField">字段名</param>
        /// <param name="m_strFrom">表名</param>
        /// <param name="m_strWhere">条件</param>
        public BuildSQL(string m_strField, string m_strFrom, string m_strWhere)
            : this()
        {
            g_strField = m_strField;
            g_strFrom = m_strFrom;
            g_strWhere = m_strWhere;

        }

        public BuildSQL(string m_strField, string m_strFrom, string m_strWhere, string m_strGroupBy)
            : this()
        {
            g_strField = m_strField;
            g_strFrom = m_strFrom;
            g_strWhere = m_strWhere;
            g_strGroupBy = m_strGroupBy;

        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strField">字段名</param>
        /// <param name="m_strFrom">表名</param>
        /// <param name="m_strWhere">条件</param>
        /// <param name="m_strOrderBy">排序</param>
        //public BuildSQL(string m_strField, string m_strFrom, string m_strWhere, string m_strOrderBy)
        //    : this()
        //{
        //    g_strField = m_strField;
        //    g_strFrom = m_strFrom;
        //    g_strWhere = m_strWhere;
        //    g_strOrderBy = m_strOrderBy;
        //}

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strField">字段名</param>
        /// <param name="m_strFrom">表名</param>
        /// <param name="m_strWhere">条件</param>
        /// <param name="m_strOrderBy">排序</param>
        /// <param name="m_strGroupBy">分组</param>
        public BuildSQL(string m_strField, string m_strFrom,
                        string m_strWhere, string m_strOrderBy, string m_strGroupBy)
            : this()
        {
            g_strField = m_strField;
            g_strFrom = m_strFrom;
            g_strWhere = m_strWhere;
            g_strOrderBy = m_strOrderBy;
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 初始化构建 SQL 语句
        /// </summary>
        /// <param name="m_strField">字段名</param>
        /// <param name="m_strFrom">表名</param>
        /// <param name="m_strWhere">条件</param>
        /// <param name="m_strOrderBy">排序</param>
        /// <param name="m_strGroupBy">分组</param>
        /// <param name="m_strOther">其它</param>
        public BuildSQL(string m_strField, string m_strFrom, string m_strWhere,
                        string m_strOrderBy, string m_strGroupBy, string m_strOther)
            : this()
        {
            g_strField = m_strField;
            g_strFrom = m_strFrom;
            g_strWhere = m_strWhere;
            g_strOrderBy = m_strOrderBy;
            g_strOther = m_strOther;
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 获取统计记录数的 SQL 语句
        /// </summary>
        /// <returns>返回 SQL 语句</returns>
        public string getRowTotalSQL()
        {
            return "SELECT COUNT(1) " + getFromSQL();
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 构建 SQL 语句
        /// </summary>
        /// <returns>返回 SQL 语句</returns>
        public string getSQL()
        {
            return "SELECT " + g_strField + getFromSQL()
                             + (g_strOrderBy != "" ? " ORDER BY " + g_strOrderBy : "")
                             + (g_strGroupBy != "" ? " GROUP BY " + g_strGroupBy : "")
                             + g_strOther;
        }

        //--------------------------------------------------------------------------------------------
        /// <summary>
        /// 获取除字段信息外的 SQL 语句
        /// </summary>
        /// <returns>返回 SQL 语句</returns>
        private string getFromSQL()
        {
            return " FROM " + g_strFrom
                            + (g_strWhere != "" ? " WHERE " + g_strWhere : "");
        }

        #endregion

    }
}

实例：将sql server数据库中的数据导入到station的gridview中

连接到数据库：

<appSettings>
    <!--数据库连接字符串-->
    <add key="DBConnString" value="Data Source=localhost;database=manager;uid=sa;pwd=sa;" />
  </appSettings>

在station页面page_load时加载dataBind(sender,e)方法：

 private void dataBind(object sender, System.EventArgs e)
    {
        #region SELECT FIELD 语句

        StringBuilder sbField = new StringBuilder();
        sbField.Append(" a.id");
        sbField.Append(" ,a.tname");
        sbField.Append(" ,a.agency ");
        sbField.Append(" ,a.province");
        sbField.Append(" ,a.city");
        sbField.Append(" ,a.address");
        sbField.Append(" ,a.long");
        sbField.Append(" ,a.lat");
        sbField.Append(" ,a.error");
        sbField.Append(" ,a.tperson");
        sbField.Append(" ,a.perphone");
        sbField.Append(" ,b.sname");
        sbField.Append(" ,b.sperson");
        sbField.Append(" ,b.sphone");
        sbField.Append(" ,a.bgtime");
        sbField.Append(" ,a.endtime");
        sbField.Append(" ,a.ctime");

        #endregion SELECT FIELD 语句

        #region SELECT FROM 语句

        StringBuilder sbFrom = new StringBuilder();
        sbFrom.Append(" station a ");
        //将left join语句添加至此
        sbFrom.Append(" left join service b on b.id = a.service ");
        //sbFrom.Append(" left join engineer c on c.service = b.id ");

        #endregion SELECT FROM 语句

        #region SELECT WHERE 语句

        List<SqlParameter> paramList = new List<SqlParameter>();
        StringBuilder sbWhere = new StringBuilder();

        sbWhere.Append(" 1 = 1 ");

        if (!string.IsNullOrWhiteSpace(TextBox1.Text))
        {
            sbWhere.Append(" and a.tname like @tname ");
            paramList.Add(new SqlParameter("@tname", "%" + TextBox1.Text + "%"));
        }
        if (!string.IsNullOrWhiteSpace(TextBox2.Text))
        {
            sbWhere.Append(" and a.city like @city ");
            paramList.Add(new SqlParameter("@city", "%" + TextBox2.Text + "%"));
        }

        #endregion SELECT WHERE 语句

        //StringBuilder sbGroupBy = new StringBuilder();
        //sbGroupBy.Append(" group by a.tname ");

        #region SELECT 语句

        //SQL语句
        BuildSQL bsSQL = new BuildSQL
            (sbField.ToString(), sbFrom.ToString(), sbWhere.ToString());
        //传递参数
        SqlParameter[] bsParam = paramList.ToArray();

        #endregion SELECT 语句

        #region 分页绑定

        uc_GvPage.RowTotal = GvDataBind.getRowTotal(bsSQL, bsParam);
        uc_GvPage.init_Lbl();

        //获取显示的数据
        bsSQL.Start = uc_GvPage.RowNum;
        bsSQL.RowCnt = uc_GvPage.RowCount;
        GvDataBind.dataBind(GridView1, bsSQL, bsParam);

        #endregion 分页绑定
    }

至此，实例分析完毕。

源码网址：这里写链接内容

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