ADO.NET帮助类DBHelper
一. DBHelper帮助类
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace DAL { /// <summary> /// 数据库操作帮助类 /// </summary> public class DBHelper { //连接字符串,从web.config中获取 public static string conStr = ConfigurationManager.ConnectionStrings["DBConnectionString1"].ConnectionString; /// <summary> /// 获取SqlCommand对象 /// </summary> /// <param name="sql">sql语句</param> /// <param name="conn">数据库连接对象</param> /// <param name="pars">参数集</param> /// <returns>SqlCommand对象</returns> private static SqlCommand GetSqlCommand(string sql, SqlConnection conn, params SqlParameter[] pars) { conn.Open(); SqlCommand comm = new SqlCommand(sql, conn); comm.Parameters.AddRange(pars); return comm; } /// <summary> /// 设置SqlCommand对象的值 /// </summary> /// <param name="comm">SqlCommand对象</param> /// <param name="commandText">需要执行的sql语句或存储过程名称</param> /// <param name="conn">数据库连接对象</param> /// <param name="type">执行的类型(sql语句类型或存储过程类型)</param> private static void SetSqlCommand(SqlCommand comm, string commandText, SqlConnection conn, CommandType type) { comm.CommandText = commandText; comm.Connection = conn; comm.CommandType = type; } /// 查询返回SqlDataReader,读取数据完毕后必须关闭SqlDataReader，会自动释放数据库连接 /// </summary> /// <param name="sql">sql语句</param> /// <param name="pars">参数集</param> /// <returns>SqlDataReader</returns> public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] pars) { SqlConnection conn = new SqlConnection(conStr); SqlCommand comm = GetSqlCommand(sql, conn, pars); return comm.ExecuteReader(CommandBehavior.CloseConnection); } /// <summary> /// 执行查询，返回结果集的第一行第一列数据 /// </summary> /// <param name="sql">sql语句</param> /// <param name="pars">参数集</param> /// <returns>单个数据</returns> public static object ExecuteScalar(string sql, params SqlParameter[] pars) { using (SqlConnection conn = new SqlConnection(conStr)) { SqlCommand comm = GetSqlCommand(sql, conn, pars); return comm.ExecuteScalar(); } } /// <summary> /// 执行增删改操作 /// </summary> /// <param name="sql">sql语句</param> /// <param name="pars">参数集</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(string sql, params SqlParameter[] pars) { using (SqlConnection conn = new SqlConnection(conStr)) { SqlCommand comm = GetSqlCommand(sql, conn, pars); return comm.ExecuteNonQuery(); } } /// <summary> /// 执行查询语句,返回DataTable /// </summary> /// <param name="sql">sql语句</param> /// <param name="pars">参数集</param> /// <returns>DataTable</returns> public static DataTable ExecuteAdapter(string sql, params SqlParameter[] pars) { DataTable dt = new DataTable(); using (SqlConnection conn = new SqlConnection(conStr)) { SqlDataAdapter adapter = new SqlDataAdapter(sql, conn); adapter.SelectCommand.Parameters.AddRange(pars); adapter.Fill(dt); } return dt; } /// 调用存储过程返回SqlDataReader,读取数据完毕后必须关闭SqlDataReader，会自动释放数据库连接 /// </summary> /// <param name="procedureName">存储过程名称</param> /// <param name="comm">Sqlcommand对象</param> /// <returns>SqlDataReader</returns> public static SqlDataReader ExecuteReader(string procedureName, SqlCommand comm) { SqlConnection conn = new SqlConnection(conStr); SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure); return comm.ExecuteReader(CommandBehavior.CloseConnection); } /// <summary> /// 调用存储过程，返回结果集的第一行第一列数据 /// </summary> /// <param name="procedureName">存储过程名称</param> /// <param name="comm">Sqlcommand对象</param> /// <returns>单个数据</returns> public static object ExecuteScalar(string procedureName, SqlCommand comm) { using (SqlConnection conn = new SqlConnection(conStr)) { SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure); return comm.ExecuteScalar(); } } /// <summary> /// 调用存储过程，执行非查询操作(增删改) /// </summary> /// <param name="procedureName">存储过程名称</param> /// <param name="comm">Sqlcommand对象</param> /// <returns>受影响的行数</returns> public static int ExecuteNonQuery(string procedureName, SqlCommand comm) { using (SqlConnection conn = new SqlConnection(conStr)) { SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure); return comm.ExecuteNonQuery(); } } /// <summary> /// 执行存储过程,返回DataTable /// </summary> /// <param name="procedureName">存储过程名称</param> /// <param name="comm">Sqlcommand对象</param> /// <returns>DataTable</returns> public static DataTable ExecuteAdapter(string procedureName, SqlCommand comm) { DataTable dt = new DataTable(); using (SqlConnection conn = new SqlConnection(conStr)) { SetSqlCommand(comm, procedureName, conn, CommandType.StoredProcedure); SqlDataAdapter adapter = new SqlDataAdapter(comm); adapter.Fill(dt); } return dt; } /// <summary> /// 使用事务执行多个非查询操作，sql语句不能相同 /// </summary> /// <param name="sqlList">键：sql语句 值：参数集</param> /// <returns>是否全都成功执行</returns> public static bool ExecuteWithTransaction(Dictionary<string, List<SqlParameter>> sqlList) { using (SqlConnection conn = new SqlConnection(conStr)) { conn.Open(); SqlTransaction tran = conn.BeginTransaction(); SqlCommand comm = new SqlCommand(); comm.Connection = conn; comm.Transaction = tran; try { foreach (var v in sqlList) { comm.Parameters.Clear(); comm.CommandText = v.Key; if (v.Value != null && v.Value.Count > 0) { comm.Parameters.AddRange(v.Value.ToArray()); } comm.ExecuteNonQuery(); } tran.Commit(); return true; } catch (Exception) { tran.Rollback(); return false; } } } /// <summary> /// 使用事务执行多个非查询操作，通用 /// </summary> /// <param name="sqlList">SQL对象</param> /// <returns>是否全都成功执行</returns> public static bool ExecuteWithTransaction(List<SQL> sqlList) { using (SqlConnection conn = new SqlConnection(conStr)) { conn.Open(); SqlTransaction tran = conn.BeginTransaction(); SqlCommand comm = new SqlCommand(); comm.Connection = conn; comm.Transaction = tran; try { foreach (var v in sqlList) { comm.Parameters.Clear(); comm.CommandText = v.Sql; if (v.ParameterList != null && v.ParameterList.Count > 0) { comm.Parameters.AddRange(v.ParameterList.ToArray()); } comm.ExecuteNonQuery(); } tran.Commit(); return true; } catch (Exception) { tran.Rollback(); return false; } } } } /// <summary> /// SQL类,包含sql语句和参数集 /// </summary> public class SQL { public string Sql { get; set; } public List<SqlParameter> ParameterList { get; set; } public SQL(string sql, List<SqlParameter> pars) { this.Sql = sql; this.ParameterList = pars; } public SQL(string sql) { this.Sql = sql; } public SQL() { } } }
二.例子
存储过程
alter proc p_getByGender @Gender char(1)=0, @Count int output as declare @CountSql nvarchar(4000) set @CountSql='select @Count=count(1) from Student' exec sp_executesql @CountSql,N'@Count int output',@Count output declare @Sql nvarchar(4000) set @Sql='select * from Student where Gender = '+CHAR(39)+@Gender+CHAR(39) print @Gender print @Sql exec(@Sql) go
ADO.net调用
//创建SqlCommand对象 SqlCommand comm = new SqlCommand(); //设置存储过程的参数 comm.Parameters.Add("@Count", SqlDbType.Int).Direction = ParameterDirection.Output; comm.Parameters.Add("@Gender", SqlDbType.Char, 1).Value = 0; //调用DBHelper的方法返回结果 DataTable dt=DBHelper.ExecuteAdapter("p_getByGender", comm); //储存过程的输出参数 int count = (int)comm.Parameters["@Count"].Value;