一、前言
因为很多人一般进行一系列相关数据库操作都是在存储过程里面，而且在存储过程用锁的写法也是很简单的，在这篇文章主要介绍一下C#后台代码用锁进行一系列事务操作，我建立一个简单的winform程序，然后做一个事务：修改指定ID的用户信息，然后新增一名用户信息，操作成功就提交事务，程序异常和数据库执行不成功都必须回滚事务！
二、存储过程的事务
写得比较简单，我想大家都知道怎么使用了，不懂的可以问我。
三、C#代码的事务
1.封装一个事务类，里面有事务的创建、提交事务、回滚事务和销毁事务的方法
public class TransactionDal : SqlHelper { public DbConnection dbconnection = null; public DbTransaction transaction = null; public void BeginTransaction() { dbconnection = SqlHelper.CreateConnection(); dbconnection.Open(); transaction = dbconnection.BeginTransaction(); } public void CommitTransaction() { if (null != transaction) { transaction.Commit(); } } public void RollbackTransaction() { if (null != transaction) { transaction.Rollback(); } } public void DisposeTransaction() { if (dbconnection.State == ConnectionState.Open) { dbconnection.Close(); } if (null != transaction) { transaction.Dispose(); } } }
2.封装简单的数据层用到事务的方法
public class SqlHelper { private static readonly string constr = ConfigurationManager.ConnectionStrings["strCon"].ConnectionString; /// <summary> /// 有锁的事务方法 /// </summary> /// <param name="tran"></param> /// <param name="sql"></param> /// <param name="pms"></param> /// <returns></returns> public static int ExecuteNonQuery(IDbTransaction tran,string sql, params SqlParameter[] pms) { using (SqlCommand cmd = new SqlCommand(sql, (SqlConnection)tran.Connection, (SqlTransaction)tran)) { if (pms != null) { cmd.Parameters.AddRange(pms); } return cmd.ExecuteNonQuery(); } } public static DataTable ExecuteDataTable(string sql, params SqlParameter[] pms) { SqlDataAdapter adapter = new SqlDataAdapter(sql, constr); if (pms != null) { adapter.SelectCommand.Parameters.AddRange(pms); } DataTable dt = new DataTable(); adapter.Fill(dt); return dt; } protected static System.Data.Common.DbConnection CreateConnection() { SqlConnection con = new SqlConnection(constr); return con; } }
3.winform程序
3.1程序界面
3.2C#代码修改用户信息并新增用户信息用到了事务
public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { dataGridView1.DataSource = GetUsersTable(); } /// <summary> /// 给dataGridView绑定数据源 /// </summary> /// <returns></returns> private DataTable GetUsersTable() { string sql = "select * from Users"; DataTable dt = SqlHelper.ExecuteDataTable(sql, null); return dt; } /// <summary> /// 点击修改并新增按钮 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void button_Click(object sender, EventArgs e) { string strUserID = txtID.Text.Trim(); string strUserName = txtUserName.Text.Trim(); string strAge = txtAge.Text.Trim(); string strAddress = txtAddress.Text.Trim(); string strNewUserName = txtNewUserName.Text.Trim(); string strNewAge = txtNewAge.Text.Trim(); string strNewAddress = txtNewAddress.Text.Trim(); if (strUserID != "" && strUserName != "" && strAge != "" && strAddress != "" && strNewUserName != "" && strNewAge != "" && strNewAddress != "") { int error = UpdateUserMsg(strUserID, strUserName, strAge, strAddress, strNewUserName, strNewAge, strNewAddress); if (error == 0) { dataGridView1.DataSource = GetUsersTable();//重新绑定学生数据源 MessageBox.Show("整个事务操作成功"); } else { MessageBox.Show("整个事务操作失败"); } } else { MessageBox.Show("请填写完整信息"); } } /// <summary> /// 修改指定学生信息 /// </summary> /// <returns></returns> private int UpdateUserMsg(string strUserID, string strUserName, string strAge, string strAddress, string strNewUserName, string strNewAge, string strNewAddress) { TransactionDal dalTran = new TransactionDal(); //实例化封装好事务类的TransactionDal int error = 0; try { dalTran.BeginTransaction(); //这里开启事务锁 string sql = string.Format("update Users set UserName='{0}',Age={1},Address='{2}' where UserID={3}", strUserName, strAge, strAddress, strUserID); int mod = SqlHelper.ExecuteNonQuery(dalTran.transaction, sql, null); //传参：事务锁，sql, null ，执行修改操作 if (mod > 0)//执行成功 { int mod2 = AddUser(dalTran.transaction, strNewUserName, strNewAge, strNewAddress);//如果一系列操作是相关的也要传递锁过去 if (mod > 0) { dalTran.CommitTransaction(); //执行提交 } else { //执行失败回滚 error += 1; dalTran.RollbackTransaction(); } } else //执行失败回滚 { error += 1; dalTran.RollbackTransaction(); return error; } } catch (Exception) { //执行异常回滚 error += 1; dalTran.RollbackTransaction(); } finally { dalTran.DisposeTransaction(); //释放锁，释放连接实例 } return error; } //新增学生,在整个事务中也需要传递同个事务事例 private int AddUser(IDbTransaction tran, string strNewUserName, string strNewAge, string strNewAddress) { string sql = string.Format("insert into Users values('{0}',{1},'{2}')", strNewUserName, strNewAge, strNewAddress); int mod = SqlHelper.ExecuteNonQuery(tran, sql, null); return mod; } }
四、总结
C#事务锁要try{}catch{}finally{},在一系列相关操作的时候开启了事务锁就只能在同一个数据库连接实例进行锁的操作， 代码都写得比较简单，大家会用C#代码事务，封装合适自己使用的就好了。