操作数据库工具类：

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;namespace face
{/// <summary>/// 数据库工具类/// </summary>public class SqlHelper{#region 获取数据库连接private static string GetConnectionString{get{return "Data Source=.;Initial Catalog=TestFaceDB;Persist Security Info=True;User ID=sa;Password=171268"; //转换成string类型}}#endregion#region 查询多条记录/// <summary>/// 查询多条记录/// params SqlParameter  param  表示既可以传过来数组  也可以传过来单个值/// </summary>/// <param name="sql"></param>/// <param name="type"></param>/// <param name="param"></param>/// <returns></returns>public static SqlDataReader ExcuteReader(string sql, CommandType type, params SqlParameter[] param){SqlConnection conn = new SqlConnection(GetConnectionString);SqlCommand cmd = new SqlCommand(sql, conn);PreaPareCommand(sql, conn, cmd, type, param);//参数是关闭连接return cmd.ExecuteReader(CommandBehavior.CloseConnection);}#endregion#region DataSetpublic static DataSet ExexuteDataset(string sql, CommandType type, params SqlParameter[] param){using (SqlConnection conn = new SqlConnection(GetConnectionString)){SqlCommand cmd = new SqlCommand(sql, conn);PreaPareCommand(sql, conn, cmd, type, param);SqlDataAdapter sda = new SqlDataAdapter(cmd);DataSet ds = new DataSet();sda.Fill(ds);return ds;}}#endregion#region 查询返回一条记录/// <summary>/// 查询返回一条记录/// </summary>/// <param name="sql"></param>/// <param name="type"></param>/// <param name="param"></param>/// <returns></returns>public static Object ExecuteScalar(string sql, CommandType type, params SqlParameter[] param){using (SqlConnection conn = new SqlConnection(GetConnectionString)){SqlCommand cmd = new SqlCommand(sql, conn);PreaPareCommand(sql, conn, cmd, type, param);return cmd.ExecuteScalar();}}#endregion#region 命令对象装配//命令对象装配private static void PreaPareCommand(string sql, SqlConnection conn, SqlCommand cmd, CommandType type, params SqlParameter[] param){if (conn.State != ConnectionState.Open){conn.Close();conn.Open();}cmd.CommandType = type;if (param != null){foreach (SqlParameter p in param){cmd.Parameters.Add(p);}}}#endregion#region 增删改public static int ExecuteNonQuery(string sql, CommandType type, params SqlParameter[] param){using (SqlConnection conn = new SqlConnection(GetConnectionString)){SqlCommand cmd = new SqlCommand(sql, conn);PreaPareCommand(sql, conn, cmd, type, param);return cmd.ExecuteNonQuery();}}#endregion}
}