同一个SqlHelper链接不同的数据库

先创建一个基本的SqlHelperBase，用于继承和实现数据库操作功能：

using System.Data;
using System.Data.SqlClient;
using System.Text;namespace RongZi.DBUtility
{public class SqlHelperBase{#region 属性public string ConnStr;private SqlConnection conn = null;//数据库链接对象 private SqlCommand cmd = null;//数据库操作private SqlDataReader sdr = null;//数据集#endregion 属性#region 基本用法/// <summary>/// 链接数据库/// </summary>/// <returns></returns>private SqlConnection GetConn(){conn = new SqlConnection(ConnStr);if (conn.State == ConnectionState.Closed){conn.Open();}return conn;}/// <summary>/// 增删改 INSERT|DELETE|UPDATE/// SqlParameter[] paras = new SqlParameter[]{new SqlParameter("@Name",DBNull.Value),}; /// </summary>public int ExecuteNonQuery(string sqlStr, SqlParameter[] sqlparas = null){using (cmd = new SqlCommand(sqlStr, GetConn())){//cmd.CommandTimeout = 600;if (sqlparas != null) cmd.Parameters.AddRange(sqlparas);int res = cmd.ExecuteNonQuery();conn.Close();return res;}}/// <summary>/// 查 SELECT/// SqlParameter[] paras = new SqlParameter[]{new SqlParameter("@Name",DBNull.Value),}; /// </summary>public DataTable ExecuteReader(string sqlStr, SqlParameter[] sqlparas = null){using (cmd = new SqlCommand(sqlStr, GetConn())){cmd.CommandTimeout = 600;DataTable dt = new DataTable();if (sqlparas != null) cmd.Parameters.AddRange(sqlparas);using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection)){dt.Load(sdr);}conn.Close();return dt;}}/// <summary>/// 执行查询，并返回查询所返回的结果集中第一行的第一列。 如：/// insert一条数据，返回自增的id值：insert into table([NAME])values ('名字');Select @@Identity;/// </summary>public object ExecuteScalar(string sqlStr, SqlParameter[] sqlparas = null){using (cmd = new SqlCommand(sqlStr, GetConn())){cmd.CommandTimeout = 600;if (sqlparas != null) cmd.Parameters.AddRange(sqlparas);object res = cmd.ExecuteScalar();conn.Close();return res;}}#endregion 基本用法#region 存储过程/// <summary>/// 执行存储过程/// </summary>/// <param name="proc">存储过程名称</param>/// <param name="spArr">参数</param>/// <returns>受影响的行数</returns>public int ExecuteNonQuery_ForProc(string proc, SqlParameter[] spArr = null){cmd = new SqlCommand(proc, GetConn());//cmd.CommandTimeout = 600;cmd.CommandType = CommandType.StoredProcedure;if (spArr != null) cmd.Parameters.AddRange(spArr);int i = cmd.ExecuteNonQuery();conn.Close();return i;}/// <summary>/// 执行存储过程-带输出参数(最后一个参数)/// </summary>/// <param name="proc">存储过程名称</param>/// <param name="spArr">参数</param>/// <returns>输出参数的值</returns>public object ExecuteNonQuery_ForProc_Output(string ProcName, SqlParameter[] parm){cmd = new SqlCommand(ProcName, GetConn());//cmd.CommandTimeout = 600;//最后一个参数为输出参数parm[parm.Length - 1].Direction = ParameterDirection.Output;cmd.CommandType = CommandType.StoredProcedure;if (parm != null){cmd.Parameters.AddRange(parm);}int result = cmd.ExecuteNonQuery();conn.Close();//返回输出的参数,看存储过程中定义的输出参数是什么类型,这里就转换成什么类型return parm[parm.Length - 1].Value;}#endregion#region 事物/// <summary>/// 事物-执行多条操作(INSERT|UPDATE|DELETE)语句/// </summary>/// <param name="Sqlstr">sql语句数组</param>/// <returns></returns>public int ExecTran(string[] Sqlstr){conn = GetConn();SqlTransaction tran = conn.BeginTransaction();//开始事物cmd = new SqlCommand();cmd.Connection = conn;cmd.Transaction = tran;//cmd.CommandTimeout = 600;try{int count = Sqlstr.Length;for (int i = 0; i < count; i++){cmd.CommandText = Sqlstr[i];cmd.ExecuteNonQuery();}tran.Commit();//提交事物return 1;}catch{tran.Rollback();//回滚事物return 0;}finally{conn.Close();tran.Dispose();}}#endregion#region 常用方法public DataTable SELECT(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteReader(sqlStr, sqlparas);}public int COUNT(string sqlStr, SqlParameter[] sqlparas = null){int i = 0;object obj = ExecuteScalar(sqlStr, sqlparas);int.TryParse(obj.ToString(), out i);return i;}public int INSERT(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteNonQuery(sqlStr, sqlparas);}public int UPDATE(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteNonQuery(sqlStr, sqlparas);}public int DELETE(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteNonQuery(sqlStr, sqlparas);}public int DELETE(string table, string key, object keyValue){string sqlStr = "DELETE FROM [" + table + "] WHERE [" + key + "]='" + keyValue + "'";return ExecuteNonQuery(sqlStr);}#endregion#region 特殊方法 public DataTable Query(string sqlStr){return ExecuteReader(sqlStr);}public DataTable Query(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteReader(sqlStr, sqlparas);}/// <summary>/// 执行Insert、Update、Delete，返回操作的行数/// </summary>public int ExecuteSql(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteNonQuery(sqlStr, sqlparas);}/// <summary>/// 执行Insert,并返回新增的主键id/// </summary>public object GetSingle(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteScalar(sqlStr, sqlparas);}/// <summary>/// 判断是否存在/// </summary>public bool Exists(string sqlStr, SqlParameter[] sqlparas = null){DataTable dt = ExecuteReader(sqlStr, sqlparas);if (dt != null && dt.Rows.Count > 0){return true;}else{return false;}}//获取数据public DataTable GetData(string sqlStr, SqlParameter[] sqlparas = null){return ExecuteReader(sqlStr, sqlparas);}/// <summary>/// 简单单表查询/// </summary>/// <param name="TableName">必填</param>/// <param name="Top"></param>/// <param name="fldName"></param>/// <param name="strWhere"></param>/// <param name="orderBy"></param>/// <returns></returns>public DataTable GetData(string TableName, int Top = 0, string fldName = "", string strWhere = "", string orderBy = ""){StringBuilder strSql = new StringBuilder();strSql.Append("SELECT ");if (Top > 0){strSql.AppendFormat(" TOP {0} ", Top);}if (!string.IsNullOrEmpty(fldName)){strSql.AppendFormat(fldName + " FROM {0}", TableName);}else{strSql.AppendFormat(" * FROM {0}", TableName);}if (!string.IsNullOrEmpty(strWhere)){strSql.Append(" WHERE " + strWhere);}if (!string.IsNullOrEmpty(orderBy)){strSql.Append(" ORDER BY " + orderBy);}DataTable dt = ExecuteReader(strSql.ToString());return dt;}public int GetCount(string TableName, string strWhere = ""){StringBuilder strSql = new StringBuilder();strSql.Append("select COUNT(*) from " + TableName);if (!string.IsNullOrEmpty(strWhere)){strSql.Append(" where " + strWhere);}int i = 0;object obj = ExecuteScalar(strSql.ToString());int.TryParse(obj.ToString(), out i);return i;}/// <summary>/// SQL分页查询/// </summary>/// <param name="TableName">表名</param>/// <param name="fldName">显示字段</param>/// <param name="strWhere">where条件</param>/// <param name="orderBy">排序</param>/// <param name="PageSize">每页多少数据</param>/// <param name="PageIndex">当前第几页</param>/// <returns></returns>public DataTable PAGING(string TableName, string fldName, string strWhere, string orderBy, int PageSize = 500, int PageIndex = 1){StringBuilder strSql = new StringBuilder();strSql.AppendLine("DECLARE @PageSize INT;");strSql.AppendLine("DECLARE @PageIndex INT;");strSql.AppendLine("SET @PageSize=" + PageSize + ";");strSql.AppendLine("SET @PageIndex=" + PageIndex + ";");strSql.Append("SELECT ");if (!string.IsNullOrEmpty(fldName)){strSql.Append(fldName + " FROM (");}else{strSql.Append(" * FROM (");}strSql.AppendFormat(" SELECT ROW_NUMBER() OVER(ORDER BY {0}) rownum,", orderBy);if (!string.IsNullOrEmpty(fldName)){strSql.AppendFormat(fldName + " FROM {0}", TableName);}else{strSql.AppendFormat(" * FROM {0}", TableName);}if (!string.IsNullOrEmpty(strWhere)){strSql.AppendLine(" WHERE " + strWhere);}strSql.AppendLine(" )a");strSql.AppendLine(" WHERE rownum > @PageSize * (@PageIndex - 1) AND rownum <= @PageSize * @PageIndex ");if (!string.IsNullOrEmpty(orderBy)){strSql.Append(" ORDER BY " + orderBy);}DataTable dt = ExecuteReader(strSql.ToString());return dt;}/// <summary>/// SQL分页查询 /// 该语法支持SQL Server2012及以上版本/// </summary>/// <param name="TableName">表名(必填)</param>/// <param name="fldName">显示字段(缺省为:*)</param>/// <param name="strWhere">查询条件</param>/// <param name="orderBy">排序条件</param>/// <param name="PageSize">每页行数</param>/// <param name="PageIndex">第几页</param>/// <returns></returns>public DataTable PAGING_2012(string TableName, string fldName, string strWhere, string orderBy = "", int PageSize = 500, int PageIndex = 1){StringBuilder strSql = new StringBuilder();strSql.Append("SELECT ");if (!string.IsNullOrWhiteSpace(fldName)){strSql.AppendFormat(fldName + " FROM {0}", TableName);//指定字段}else{strSql.AppendFormat(" * FROM {0}", TableName);//全部字段}if (!string.IsNullOrWhiteSpace(strWhere)){strSql.Append(" WHERE " + strWhere);}if (!string.IsNullOrWhiteSpace(orderBy)){strSql.AppendFormat(" order by {0} offset {1} rows fetch next {2} rows only ", orderBy, (PageIndex - 1) * PageSize, PageSize);}else{strSql.AppendFormat(" order by 1 offset {0} rows fetch next {1} rows only ", (PageIndex - 1) * PageSize, PageSize);//默认以第1个字段排序}//解释一下：offset N rows 跳过前N条，fetch next M rows only 获取下面的M条信息。DataTable dt = ExecuteReader(strSql.ToString());return dt;}/// <summary>/// SQL分页查询 /// 该语法支持SQL Server2012及以上版本/// </summary>/// <param name="sqlStr">sql语句</param>/// <param name="orderBy">排序</param>/// <param name="PageSize">每页行数</param>/// <param name="PageIndex">第几页</param>/// <returns></returns>public DataTable PAGING_2012(string sqlStr, string orderBy = "", int PageSize = 500, int PageIndex = 1){StringBuilder strSql = new StringBuilder();strSql.Append(sqlStr);if (!string.IsNullOrWhiteSpace(orderBy)){strSql.AppendFormat(" order by {0} offset {1} rows fetch next {2} rows only ", orderBy, (PageIndex - 1) * PageSize, PageSize);}else{strSql.AppendFormat(" order by 1 offset {0} rows fetch next {1} rows only ", (PageIndex - 1) * PageSize, PageSize);//默认以第1个字段排序}//解释一下：offset N rows 跳过前N条，fetch next M rows only 获取下面的M条信息。DataTable dt = ExecuteReader(strSql.ToString());return dt;}/// <summary>/// DataTable分页查询/// </summary>/// <param name="data">DataTable</param>/// <param name="allPage">一共有几页</param>/// <param name="PageSize">每页几行数据</param>/// <param name="PageIndex">第几页</param>/// <returns></returns>public DataTable GetDataTablePage(DataTable data, out int allPage, int PageSize = 500, int PageIndex = 1){allPage = data.Rows.Count / PageSize;allPage += data.Rows.Count % PageSize == 0 ? 0 : 1;DataTable dt = data.Clone();int startIndex = PageIndex * PageSize;int endIndex = startIndex + PageSize > data.Rows.Count ? data.Rows.Count : startIndex + PageSize;if (startIndex < endIndex){for (int i = startIndex; i < endIndex; i++){dt.ImportRow(data.Rows[i]);}}return dt;}/// <summary>/// 获取最大ID/// </summary>/// <param name="tableName">表名</param>/// <param name="idRow">主键的列名</param>/// <param name="addOne">是否+1</param>/// <returns></returns>public int GetMaxID(string tableName, string idRow, bool addOne = false){int i = 0;string sql = "SELECT ISNULL(MAX([" + idRow + "]),0) FROM [" + tableName + "]";object obj = ExecuteScalar(sql);int.TryParse(obj.ToString(), out i);if (addOne == true)//+1{return i + 1;}return i;}#endregion}
}

创建SqlHelper子类，继承父类，仅仅给父类提供数据库链接字符串：

using System.Configuration;public class TestSqlHelper : SqlHelperBase//①继承父类SqlHelperBase{public TestSqlHelper()//②创建构造函数{base.ConnStr = ConfigurationManager.ConnectionStrings["TianmaoData"].ConnectionString;//③改写父类连接字符串           }}

调用子类：

        public ActionResult Test(){string sql = "SELECT COUNT(*) cc  FROM [TableName]";TestSqlHelper ts = new TestSqlHelper();ViewBag.COUNT = ts.COUNT(sql);return View();}

说明：

父类不可有 static，静态的不会被子类继承，值永远是null；
子类在“构造函数”里修改父类的变量值；
子类修改父类的值用：base.父类的参数=新值；
举例：base.ConnStr = ConfigurationManager.ConnectionStrings["DB"].ConnectionString;

同一个SqlHelper链接不同的数据库相关推荐

linux链接达梦数据库,linux下面达梦数据库的JDBC链接
此次由于学习上面的事情,接触到了达梦数据库,这是第一次用,去年有个关于隐通道的课程设计,其实就已经差很少算了解了点点,相对与国外主流数据库,Dm7有个很明显的特色,那就是它的安全级别,国外数据卖给中国 ...
python建立数据库和基本表_python基础 — 链接 Mysql 创建数据库和创表
重点: 1. 链接服务器的数据库 2. 创建表和格式 3. 插入多行数据 import pymysql try: host='xxx' user='xxx' passwd='xxx' db='test ...
简单的PL/SQl链接远程ORACLE数据库方法
简单的PL/SQl链接远程ORACLE数据库方法 PLSQL Developer新手使用教程 pasting 转载于:https://www.cnblogs.com/jing1617/p/724156 ...
使用IDEA 的DBMS 链接达梦数据库
使用IDEA 的DBMS 链接达梦数据库本机环境系统软件 JDK 环境 Win10 64 位 DM 8 17 第一步首先需要载入达梦的相关驱动程序,本文使用 DmJdbcDriver17.ja ...
孤傲苍狼只为成功找方法，不为失败找借口！ javaweb学习总结(三十九)——数据库连接池一、应用程序直接获取数据库连接的缺点　　用户每次请求都需要向数据库获得链接，而数据库创建连接通常需要
孤傲苍狼只为成功找方法,不为失败找借口! javaweb学习总结(三十九)--数据库连接池一.应用程序直接获取数据库连接的缺点用户每次请求都需要向数据库获得链接,而数据库创建连接通常需要消耗相对 ...
php mysql简单链接_php mysql 数据库链接简单例子
这里是面向过程的mysql链接,两个文件,config.php和conn.php,只是记录一下,不喜勿喷,也希望有好的建议,代码如下: config.php /* * 与数据库链接有关的配置变量保存在 ...
django 链接多个数据库并使用原生sql
settings文件如下: DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', ...
为什么链接不上mysql数据库_java链接不上数据库，怎么解决！
居正w 去年刚好做过这个,给你贴下我的链接代码try { Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver ...
php链接本地mysql数据库配置文件_php连接 mysql 数据库如何添加一个公共的配置文件...
展开全部 php面向对象文件名DB.class.php<?php header("content-type:text/html;charset=utf-8"); class ...

同一个SqlHelper链接不同的数据库

先创建一个基本的SqlHelperBase，用于继承和实现数据库操作功能：

创建SqlHelper子类，继承父类，仅仅给父类提供数据库链接字符串：

调用子类：

说明：

同一个SqlHelper链接不同的数据库相关推荐

最新文章

热门文章