实用的DBHelper

最新推荐文章于 2025-05-11 22:44:23 发布
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最新推荐文章于 2025-05-11 22:44:23 发布
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分类专栏： ASP.NET 文章标签： parameters dataset 存储 sql null 数据库
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 using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
namespace AjaxApp.DAL
{
    /// <summary> 
    /// Copyright (C) 2004-2008 LiTianPing 
    /// All rights reserved 
    /// 数据访问基础类 
    /// 用户可以修改满足自己项目的需要。 
    /// </summary> 
    public static class DBHelper
    {
        //在web.config中配置连接字符串 
        //<appSettings>里<add key="ConnectionString" value="Data Source=localhost;Initial Catalog=test;Integrated Security = SSPI" /> 
        static string connectionString = ConfigurationSettings.AppSettings["ConnectionString"];
        //两种方式选择一种 
        //static string connectionString="Data Source=localhost;Initial Catalog=test;Integrated Security = SSPI"; 
        #region  执行简单SQL语句 
        /// <summary> 
        /// 执行SQL语句，返回影响的记录数 
        /// </summary> 
        /// <param name="SQLString">SQL语句</param> 
        /// <returns>影响的记录数</returns> 
        public static int ExecuteSql(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                    }
                }
            }
        }
        /// <summary> 
        /// 执行多条SQL语句，实现数据库事务。 
        /// </summary> 
        /// <param name="SQLStringList">多条SQL语句</param>   
        public static void ExecuteSqlTran(ArrayList SQLStringList)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                SqlTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    for (int n = 0; n < SQLStringList.Count; n++)
                    {
                        string strsql = SQLStringList[n].ToString();
                        if (strsql.Trim().Length > 1)
                        {
                            cmd.CommandText = strsql;
                            cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    tx.Rollback();
                    throw new Exception(E.Message);
                }
            }
        }
        /// <summary> 
        /// 执行带一个存储过程参数的的SQL语句。 
        /// </summary> 
        /// <param name="SQLString">SQL语句</param> 
        /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param> 
        /// <returns>影响的记录数</returns> 
        public static int ExecuteSql(string SQLString, string content)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand cmd = new SqlCommand(SQLString, connection);
                System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText);
                myParameter.Value = content;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }
        /// <summary> 
        /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例) 
        /// </summary> 
        /// <param name="strSQL">SQL语句</param> 
        /// <param name="fs">图像字节,数据库的字段类型为image的情况</param> 
        /// <returns>影响的记录数</returns> 
        public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand cmd = new SqlCommand(strSQL, connection);
                System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.Image);
                myParameter.Value = fs;
                cmd.Parameters.Add(myParameter);
                try
                {
                    connection.Open();
                    int rows = cmd.ExecuteNonQuery();
                    return rows;
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }
        /// <summary> 
        /// 执行一条计算查询结果语句，返回查询结果（object）。 
        /// </summary> 
        /// <param name="SQLString">计算查询结果语句</param> 
        /// <returns>查询结果（object）</returns> 
        public static object GetSingle(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        object obj = cmd.ExecuteScalar();
                        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        connection.Close();
                        throw new Exception(e.Message);
                    }
                }
            }
        }
        /// <summary> 
        /// 执行查询语句，返回SqlDataReader 
        /// </summary> 
        /// <param name="strSQL">查询语句</param> 
        /// <returns>SqlDataReader</returns> 
        public static SqlDataReader ExecuteReader(string strSQL)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand(strSQL, connection);
            try
            {
                connection.Open();
                SqlDataReader myReader = cmd.ExecuteReader();
                return myReader;
            }
            catch (System.Data.SqlClient.SqlException e)
            {
                throw new Exception(e.Message);
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
        /// <summary> 
        /// 执行查询语句，返回DataSet 
        /// </summary> 
        /// <param name="SQLString">查询语句</param> 
        /// <returns>DataSet</returns> 
        public static DataSet Query(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        } 
        #endregion 
        #region 执行带参数的SQL语句 
        /// <summary> 
        /// 执行SQL语句，返回影响的记录数 
        /// </summary> 
        /// <param name="SQLString">SQL语句</param> 
        /// <returns>影响的记录数</returns> 
        public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        int rows = cmd.ExecuteNonQuery();
                        cmd.Parameters.Clear();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        throw new Exception(E.Message);
                    }
                }
            }
        }
        /// <summary> 
        /// 执行多条SQL语句，实现数据库事务。 
        /// </summary> 
        /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param> 
        public static void ExecuteSqlTran(Hashtable SQLStringList)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open();
                using (SqlTransaction trans = conn.BeginTransaction())
                {
                    SqlCommand cmd = new SqlCommand();
                    try
                    {
                        //循环 
                        foreach (DictionaryEntry myDE in SQLStringList)
                        {
                            string cmdText = myDE.Key.ToString();
                            SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
                            PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
                            int val = cmd.ExecuteNonQuery();
                            cmd.Parameters.Clear();
                            trans.Commit();
                        }
                    }
                    catch
                    {
                        trans.Rollback();
                        throw;
                    }
                }
            }
        }
        /// <summary> 
        /// 执行一条计算查询结果语句，返回查询结果（object）。 
        /// </summary> 
        /// <param name="SQLString">计算查询结果语句</param> 
        /// <returns>查询结果（object）</returns> 
        public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand())
                {
                    try
                    {
                        PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                        object obj = cmd.ExecuteScalar();
                        cmd.Parameters.Clear();
                        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
                        {
                            return null;
                        }
                        else
                        {
                            return obj;
                        }
                    }
                    catch (System.Data.SqlClient.SqlException e)
                    {
                        throw new Exception(e.Message);
                    }
                }
            }
        }
        /// <summary> 
        /// 执行查询语句，返回SqlDataReader 
        /// </summary> 
        /// <param name="strSQL">查询语句</param> 
        /// <returns>SqlDataReader</returns> 
        public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                SqlDataReader myReader = cmd.ExecuteReader();
                cmd.Parameters.Clear();
                return myReader;
            }
            catch (System.Data.SqlClient.SqlException e)
            {
                throw new Exception(e.Message);
            }
            finally
            {
                cmd.Dispose();
                connection.Close();
            }
        }
        /// <summary> 
        /// 执行查询语句，返回DataSet 
        /// </summary> 
        /// <param name="SQLString">查询语句</param> 
        /// <returns>DataSet</returns> 
        public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand cmd = new SqlCommand();
                PrepareCommand(cmd, connection, null, SQLString, cmdParms);
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();
                    try
                    {
                        da.Fill(ds, "ds");
                        cmd.Parameters.Clear();
                    }
                    catch (System.Data.SqlClient.SqlException ex)
                    {
                        throw new Exception(ex.Message);
                    }
                    return ds;
                }
            }
        }
        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText, SqlParameter[] cmdParms)
        {
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            if (trans != null)
                cmd.Transaction = trans;
            cmd.CommandType = CommandType.Text;//cmdType; 
            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        } 
        #endregion 
        #region 存储过程操作 
        /// <summary> 
        /// 执行存储过程 
        /// </summary> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <returns>SqlDataReader</returns> 
        public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlDataReader returnReader;
                connection.Open();
                SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
                command.CommandType = CommandType.StoredProcedure;
                returnReader = command.ExecuteReader();
                return returnReader;
            }
        }
        /// <summary> 
        /// 执行存储过程 
        /// </summary> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <param name="tableName">DataSet结果中的表名</param> 
        /// <returns>DataSet</returns> 
        public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet dataSet = new DataSet();
                connection.Open();
                SqlDataAdapter sqlDA = new SqlDataAdapter();
                sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
                sqlDA.Fill(dataSet, tableName);
                connection.Close();
                return dataSet;
            }
        }
        /// <summary> 
        /// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值) 
        /// </summary> 
        /// <param name="connection">数据库连接</param> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <returns>SqlCommand</returns> 
        private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
        {
            SqlCommand command = new SqlCommand(storedProcName, connection);
            command.CommandType = CommandType.StoredProcedure;
            foreach (SqlParameter parameter in parameters)
            {
                command.Parameters.Add(parameter);
            }
            return command;
        }
        /// <summary> 
        /// 执行存储过程，返回影响的行数   
        /// </summary> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <param name="rowsAffected">影响的行数</param> 
        /// <returns></returns> 
        public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                int result;
                connection.Open();
                SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);
                rowsAffected = command.ExecuteNonQuery();
                result = (int)command.Parameters["ReturnValue"].Value;
                //Connection.Close(); 
                return result;
            }
        }
        /// <summary> 
        /// 创建 SqlCommand 对象实例(用来返回一个整数值)  
        /// </summary> 
        /// <param name="storedProcName">存储过程名</param> 
        /// <param name="parameters">存储过程参数</param> 
        /// <returns>SqlCommand 对象实例</returns> 
        private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
        {
            SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
            command.Parameters.Add(new SqlParameter("ReturnValue",
                SqlDbType.Int, 4, ParameterDirection.ReturnValue,
                false, 0, 0, string.Empty, DataRowVersion.Default, null));
            return command;
        } 
        #endregion 
    }
}
 