DbHelper数据操作类

using System;
using System.Data;
using System.Data.Common;
using System.Configuration;
public class DbHelper
{
    private static string dbProviderName = ConfigurationManager.AppSettings["DbHelperProvider"];
    private static string dbConnectionString = ConfigurationManager.AppSettings["DbHelperConnectionString"];
    private DbConnection connection;
    public DbHelper()
    {
        this.connection = CreateConnection(DbHelper.dbConnectionString);
    }
    public DbHelper(string connectionString)
    {
        this.connection = CreateConnection(connectionString);
    }
    public static DbConnection CreateConnection()
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbConnection dbconn = dbfactory.CreateConnection();
        dbconn.ConnectionString = DbHelper.dbConnectionString;
        return dbconn;
    }
    public static DbConnection CreateConnection(string connectionString)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbConnection dbconn = dbfactory.CreateConnection();
        dbconn.ConnectionString = connectionString;
        return dbconn;
    }
    public DbCommand GetStoredProcCommond(string storedProcedure)
    {
        DbCommand dbCommand = connection.CreateCommand();
        dbCommand.CommandText = storedProcedure;
        dbCommand.CommandType = CommandType.StoredProcedure;
        return dbCommand;
    }
    public DbCommand GetSqlStringCommond(string sqlQuery)
    {
        DbCommand dbCommand = connection.CreateCommand();
        dbCommand.CommandText = sqlQuery;
        dbCommand.CommandType = CommandType.Text;
        return dbCommand;
    }

    #region 增加参数
    public void AddParameterCollection(DbCommand cmd, DbParameterCollection dbParameterCollection)
    {
        foreach (DbParameter dbParameter in dbParameterCollection)
        {
            cmd.Parameters.Add(dbParameter);
        }
    }
    public void AddOutParameter(DbCommand cmd, string parameterName, DbType dbType, int size)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Size = size;
        dbParameter.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(dbParameter);
    }
    public void AddInParameter(DbCommand cmd, string parameterName, DbType dbType, object value)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Value = value;
        dbParameter.Direction = ParameterDirection.Input;
        cmd.Parameters.Add(dbParameter);
    }
    public void AddReturnParameter(DbCommand cmd, string parameterName, DbType dbType)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Direction = ParameterDirection.ReturnValue;
        cmd.Parameters.Add(dbParameter);
    }
    public DbParameter GetParameter(DbCommand cmd, string parameterName)
    {
        return cmd.Parameters[parameterName];
    }

    #endregion

    #region 执行
    public DataSet ExecuteDataSet(DbCommand cmd)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataSet ds = new DataSet();
        dbDataAdapter.Fill(ds);
        return ds;
    }
    public DataTable ExecuteDataTable(DbCommand cmd)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataTable dataTable = new DataTable();
        dbDataAdapter.Fill(dataTable);
        return dataTable;
    }
    public DbDataReader ExecuteReader(DbCommand cmd)
    {
        cmd.Connection.Open();
        DbDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);            
        return reader;
    }
    public int ExecuteNonQuery(DbCommand cmd)
    {
        cmd.Connection.Open();
        int ret = cmd.ExecuteNonQuery();
        cmd.Connection.Close();
        return ret;
    }
    public object ExecuteScalar(DbCommand cmd)
    {
        cmd.Connection.Open();
        object ret = cmd.ExecuteScalar();
        cmd.Connection.Close();
        return ret;
    }
    #endregion

    #region 执行事务
    public DataSet ExecuteDataSet(DbCommand cmd,Trans t)
    {
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataSet ds = new DataSet();
        dbDataAdapter.Fill(ds);
        return ds;
    }
    public DataTable ExecuteDataTable(DbCommand cmd, Trans t)
    {
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataTable dataTable = new DataTable();
        dbDataAdapter.Fill(dataTable);
        return dataTable;
    }
    public DbDataReader ExecuteReader(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        DbDataReader reader = cmd.ExecuteReader();
        DataTable dt = new DataTable();
        return reader;
    }
    public int ExecuteNonQuery(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        int ret = cmd.ExecuteNonQuery();
        return ret;
    }
    public object ExecuteScalar(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        object ret = cmd.ExecuteScalar();
        return ret;
    }
    #endregion
}

public class Trans : IDisposable
{
    private DbConnection conn;
    private DbTransaction dbTrans;
    public DbConnection DbConnection
    {
        get { return this.conn; }
    }
    public DbTransaction DbTrans
    {
        get { return this.dbTrans; }
    }

    public Trans()
    {
        conn = DbHelper.CreateConnection();
        conn.Open();
        dbTrans = conn.BeginTransaction();
    }
    public Trans(string connectionString)
    {
        conn = DbHelper.CreateConnection(connectionString);
        conn.Open();
        dbTrans = conn.BeginTransaction();
    }
    public void Commit()
    {
        dbTrans.Commit();
        this.Colse();
    }

    public void RollBack()
    {
        dbTrans.Rollback();
        this.Colse();
    }

    public void Dispose()
    {
        this.Colse();
    }

    public void Colse()
    {
        if (conn.State == System.Data.ConnectionState.Open)
        {
            conn.Close();
        }
    }
}

1、直接执行sql语句

DbHelper db = new DbHelper();
DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('haha')");
db.ExecuteNonQuery(cmd); 

2、执行存储过程

DbHelper db = new DbHelper();
DbCommand cmd = db.GetStoredProcCommond("t1_insert");
db.AddInParameter(cmd, "@id", DbType.String, "heihei");
db.ExecuteNonQuery(cmd); 

3、返回DataSet

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("select * from t1");

DataSet ds = db.ExecuteDataSet(cmd);  

4、返回DataTable

DbHelper db = new DbHelper();

DbCommand cmd = db.GetSqlStringCommond("t1_findall");

DataTable dt = db.ExecuteDataTable(cmd); 

5、输入参数、输出参数、返回值

DbHelper db = new DbHelper();
DbCommand cmd = db.GetStoredProcCommond("t2_insert");
db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
db.AddOutParameter(cmd, "@outString", DbType.String, 20);
db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);
db.ExecuteNonQuery(cmd);
string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value 

6、DataReader使用

DbHelper db = new DbHelper();
DbCommand cmd = db.GetStoredProcCommond("t2_insert");
db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
db.AddOutParameter(cmd, "@outString", DbType.String, 20);
db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);
using (DbDataReader reader = db.ExecuteReader(cmd))
{
    dt.Load(reader);
}        
string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter

int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value 

7、事务使用

pubic void DoBusiness()
{
    using (Trans t = new Trans())
    {
        try
        {
            D1(t);
            throw new Exception();//如果有异常,会回滚滴
            D2(t);
            t.Commit();
        }
        catch
        {
            t.RollBack();
        }
    }
}
public void D1(Trans t)
{
    DbHelper db = new DbHelper();
    DbCommand cmd = db.GetStoredProcCommond("t2_insert");
    db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
    db.AddOutParameter(cmd, "@outString", DbType.String, 20);
    db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);
    if (t == null) db.ExecuteNonQuery(cmd);
    else db.ExecuteNonQuery(cmd,t);
    string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
    int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value
}
public void D2(Trans t)
{
    DbHelper db = new DbHelper();
    DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('..')");
    if (t == null) db.ExecuteNonQuery(cmd);
    else db.ExecuteNonQuery(cmd, t);

} 

数据库连接字符串：

<appSettings>
    <add key="DbHelperProvider" value="System.Data.SqlClient"/>
    <add key="DbHelperConnectionString" value="Data Source=(local);Initial Catalog=DbHelperTest;Persist Security Info=True;User ID=sa;Password=sa"/>
</appSettings> 

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转载：http://www.cnblogs.com/fanrong/archive/2007/04/25/726526.html