C# 数据库操作通用代码段

原文地址：http://www.oschina.net/code/snippet_12_1317

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace ADODoNETDemo
{
/// <summary>
/// 针对SQL Server数据库操作的通用类
/// 作者：周公
/// 日期：2009-01-08
/// Version:1.0
/// </summary>
public class SqlDbHelper
{
private string connectionString;
/// <summary>
/// 设置数据库连接字符串
/// </summary>
public string ConnectionString
{
set { connectionString = value; }
}
/// <summary>
/// 构造函数
/// </summary>
public SqlDbHelper()
: this(ConfigurationManager.ConnectionStrings["Conn"].ConnectionString)
{

}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="connectionString">数据库连接字符串</param>
public SqlDbHelper(string connectionString)
{
this.connectionString = connectionString;
}
/// <summary>
/// 执行一个查询，并返回结果集
/// </summary>
/// <param name="sql">要执行的查询SQL文本命令</param>
/// <returns>返回查询结果集</returns>
public DataTable ExecuteDataTable(string sql)
{
return ExecuteDataTable(sql, CommandType.Text, null);
}
/// <summary>
/// 执行一个查询,并返回查询结果
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <returns>返回查询结果集</returns>
public DataTable ExecuteDataTable(string sql, CommandType commandType)
{
return ExecuteDataTable(sql, commandType, null);
}
/// <summary>
/// 执行一个查询,并返回查询结果
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <param name="parameters">Transact-SQL 语句或存储过程的参数数组</param>
/// <returns></returns>
public DataTable ExecuteDataTable(string sql, CommandType commandType, SqlParameter[] parameters)
{
DataTable data = new DataTable();//实例化DataTable，用于装载查询结果集
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand command = new SqlCommand(sql, connection))
{
command.CommandType = commandType;//设置command的CommandType为指定的CommandType
//如果同时传入了参数，则添加这些参数
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
//通过包含查询SQL的SqlCommand实例来实例化SqlDataAdapter
SqlDataAdapter adapter = new SqlDataAdapter(command);

adapter.Fill(data);//填充DataTable
}
}
return data;
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的查询SQL文本命令</param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql)
{
return ExecuteReader(sql, CommandType.Text, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql, CommandType commandType)
{
return ExecuteReader(sql, commandType, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <param name="parameters">Transact-SQL 语句或存储过程的参数数组</param>
/// <returns></returns>
public SqlDataReader ExecuteReader(string sql, CommandType commandType, SqlParameter[] parameters)
{
SqlConnection connection = new SqlConnection(connectionString);
SqlCommand command = new SqlCommand(sql, connection);
//如果同时传入了参数，则添加这些参数
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
connection.Open();
//CommandBehavior.CloseConnection参数指示关闭Reader对象时关闭与其关联的Connection对象
return command.ExecuteReader(CommandBehavior.CloseConnection);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的查询SQL文本命令</param>
/// <returns></returns>
public Object ExecuteScalar(string sql)
{
return ExecuteScalar(sql, CommandType.Text, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <returns></returns>
public Object ExecuteScalar(string sql, CommandType commandType)
{
return ExecuteScalar(sql, commandType, null);
}
/// <summary>
///
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <param name="parameters">Transact-SQL 语句或存储过程的参数数组</param>
/// <returns></returns>
public Object ExecuteScalar(string sql, CommandType commandType, SqlParameter[] parameters)
{
object result = null;
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand command = new SqlCommand(sql, connection))
{
command.CommandType = commandType;//设置command的CommandType为指定的CommandType
//如果同时传入了参数，则添加这些参数
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
connection.Open();//打开数据库连接
result = command.ExecuteScalar();
}
}
return result;//返回查询结果的第一行第一列，忽略其它行和列
}
/// <summary>
/// 对数据库执行增删改操作
/// </summary>
/// <param name="sql">要执行的查询SQL文本命令</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql)
{
return ExecuteNonQuery(sql, CommandType.Text, null);
}
/// <summary>
/// 对数据库执行增删改操作
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, CommandType commandType)
{
return ExecuteNonQuery(sql, commandType, null);
}
/// <summary>
/// 对数据库执行增删改操作
/// </summary>
/// <param name="sql">要执行的SQL语句</param>
/// <param name="commandType">要执行的查询语句的类型，如存储过程或者SQL文本命令</param>
/// <param name="parameters">Transact-SQL 语句或存储过程的参数数组</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, CommandType commandType, SqlParameter[] parameters)
{
int count = 0;
using (SqlConnection connection = new SqlConnection(connectionString))
{
using (SqlCommand command = new SqlCommand(sql, connection))
{
command.CommandType = commandType;//设置command的CommandType为指定的CommandType
//如果同时传入了参数，则添加这些参数
if (parameters != null)
{
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add(parameter);
}
}
connection.Open();//打开数据库连接
count = command.ExecuteNonQuery();
}
}
return count;//返回执行增删改操作之后，数据库中受影响的行数
}
/// <summary>
/// 返回当前连接的数据库中所有由用户创建的数据库
/// </summary>
/// <returns></returns>
public DataTable GetTables()
{
DataTable data = null;
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();//打开数据库连接
data = connection.GetSchema("Tables");
}
return data;
}

}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace ADODoNETDemo
{
/// <summary>
/// 用ADO.NET实现CRUD功能
/// </summary>
public class ADODotNetCRUD
{
/// <summary>
/// 统计用户总数
/// </summary>
/// <returns></returns>
public int Count()
{
string sql = "select count(1) from UserInfo";
SqlDbHelper db = new SqlDbHelper();
return int.Parse(db.ExecuteScalar(sql).ToString());
}
/// <summary>
/// 创建用户
/// </summary>
/// <param name="info">用户实体</param>
/// <returns></returns>
public bool Create(UserInfo info)
{
string sql = "insert UserInfo(UserName,RealName,Age,Sex,Mobile,Email,Phone)values(@UserName,@RealName,@Age,@Sex,@Mobile,@Email,@Phone)";
SqlParameter[] paramters = new SqlParameter[]{
new SqlParameter("@UserName",info.UserName),
new SqlParameter("@RealName",info.RealName),
new SqlParameter("@Age",info.Age),
new SqlParameter("@Sex",info.Sex),
new SqlParameter("@Mobile",info.Mobile),
new SqlParameter("@Email",info.Email),
new SqlParameter("@Phone",info.Phone),
};
SqlDbHelper db = new SqlDbHelper();
return db.ExecuteNonQuery(sql, CommandType.Text, paramters) > 0;
}
/// <summary>
/// 读取用户信息
/// </summary>
/// <param name="userId">用户编号</param>
/// <returns></returns>
public UserInfo Read(int userId)
{
string sql = "select * from UserInfo Where UserId="+userId;
SqlDbHelper db = new SqlDbHelper();
DataTable data = db.ExecuteDataTable(sql);
if (data.Rows.Count > 0)
{
DataRow row = data.Rows[0];
UserInfo info = new UserInfo()
{
UserId=int.Parse(row["UserId"].ToString()),
UserName=row["UserName"].ToString(),
Age=byte.Parse(row["Age"].ToString()),
Email=row["Email"].ToString(),
Mobile=row["Mobile"].ToString(),
Phone=row["Phone"].ToString(),
RealName=row["RealName"].ToString(),
Sex=bool.Parse(row["Sex"].ToString())
};
return info;
}
else
{
return null;
}
}
/// <summary>
/// 更新用户信息
/// </summary>
/// <param name="info">用户实体</param>
/// <returns></returns>
public bool Update(UserInfo info)
{
string sql = "update UserInfo set UserName=@UserName,RealName=@RealName,Age=@Age,Sex=@Sex,Mobile=@Mobile,Email=@Email,Phone=@Phone where UserID=@UserID";
SqlParameter[] paramters = new SqlParameter[]{
new SqlParameter("@UserName",info.UserName),
new SqlParameter("@RealName",info.RealName),
new SqlParameter("@Age",info.Age),
new SqlParameter("@Sex",info.Sex),
new SqlParameter("@Mobile",info.Mobile),
new SqlParameter("@Email",info.Email),
new SqlParameter("@Phone",info.Phone),
new SqlParameter("@UserID",info.UserId),
};
SqlDbHelper db = new SqlDbHelper();
return db.ExecuteNonQuery(sql, CommandType.Text, paramters) > 0;
}
/// <summary>
/// 删除用户
/// </summary>
/// <param name="userId">用户编号</param>
/// <returns></returns>
public bool Delete(int userId)
{
string sql = "delete from UserInfo where UserId=" + userId;
SqlDbHelper db = new SqlDbHelper();
return db.ExecuteNonQuery(sql) > 0;
}
/// <summary>
/// 获取用户表中编号最大的用户
/// </summary>
/// <returns></returns>
public int GetMaxUserId()
{
string sql = "select max(userId) from UserInfo";
SqlDbHelper db = new SqlDbHelper();
return int.Parse(db.ExecuteScalar(sql).ToString());
}
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ADODoNETDemo;
using NUnit.Framework;

namespace NUnitTest
{
[TestFixture]
class ADODotNetTest
{
private ADODotNetCRUD instance = null;
[SetUp]
public void Initialize()
{
instance = new ADODotNetCRUD();
}
[Test]
/// <summary>
/// 统计用户总数
/// </summary>
/// <returns></returns>
public void Count()
{
Assert.Greater(instance.Count(), 0);
}
[Test]
/// <summary>
/// 创建用户
/// </summary>
/// <param name="info">用户实体</param>
/// <returns></returns>
public void Create()
{
UserInfo info = new UserInfo()
{
Age = 12,
Email = "zzz@ccav.com",
Mobile = "13812345678",
Phone = "01012345678",
RealName = "测试" + DateTime.Now.Millisecond.ToString(),
Sex = true,
UserName = "zhoufoxcn" + DateTime.Now.Millisecond.ToString()
};
instance.Create(info);
}
[Test]
/// <summary>
/// 读取用户信息
/// </summary>
/// <param name="userId">用户编号</param>
/// <returns></returns>
public void Read()
{
UserInfo info = instance.Read(1);
Assert.NotNull(info);
}
[Test]
/// <summary>
/// 更新用户信息
/// </summary>
/// <param name="info">用户实体</param>
/// <returns></returns>
public void Update()
{
UserInfo info = instance.Read(1);
info.RealName = "测试" + DateTime.Now.Millisecond.ToString();
instance.Update(info);
}
[Test]
/// <summary>
/// 删除用户
/// </summary>
/// <param name="userId">用户编号</param>
/// <returns></returns>
public void DeleteByID()
{
int userId = instance.GetMaxUserId();
instance.Delete(userId);
}
}
}