DbHelper数据操作类

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最新推荐文章于 2025-07-11 12:19:24 发布

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本文介绍了一个用于简化ADO.NET数据库操作的DbHelper类库，并通过多个示例演示了如何使用该库进行数据库插入、查询及事务处理等操作。

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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();
        }
    }
}

那么如何使用它呢?下面我给出一些基本的使用示例,基本能满足你大部分的数据库操作需要了.

1)直接执行sql语句

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

2)执行存储过程

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

3)返回DataSet

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DbHelper db = new DbHelper();
DbCommand cmd = db.GetSqlStringCommond("select * from t1");
DataSet ds = db.ExecuteDataSet(cmd);

4)返回DataTable

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DbHelper db = new DbHelper();
DbCommand cmd = db.GetSqlStringCommond("t1_findall");
DataTable dt = db.ExecuteDataTable(cmd);

5)输入参数/输出参数/返回值的使用(比较重要哦)

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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

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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)事务的使用.(项目中需要将基本的数据库操作组合成一个完整的业务流时,代码级的事务是必不可少的哦)

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public 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);
}

以上我们好像没有指定数据库连接字符串,大家如果看下DbHelper的代码,就知道要使用它必须在config中配置两个参数,如下:

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<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>

其实,DbHelper需要的仅仅是两个字符串,你可以自己修改,作成加密什么的...

好了,就这样,DbHelper的代码是非常简单和透明的,只是在ado.net上做了一点小包装,改变了一下使用它的程序员的编码方式,去除掉一些比较"物理级"的编程概念,如connection的open和close之类的,使程序员更专注于业务逻辑代码的编写,少死掉点脑细胞,另外,统一了数据操作层的数据操作代码的风格和格式,维护起来很方便的撒~~~