.net 连接sql的sqlhelper.cs
- <connectionStrings>
- <add name="connStr" connectionString="Data Source=.;Initial Catalog=newssystem;Integrated Security=True"/>
- </connectionStrings>
SQLHelper.cs文件
C#代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
namespace DAL
{
public class SQLHelper
{
public static SqlCommand cmd = null;
public static SqlConnection conn = null;
public static string connstr = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
public SQLHelper()
{ }
#region 建立数据库连接对象
/// <summary>
/// 建立数据库连接
/// </summary>
/// <returns>返回一个数据库的连接SqlConnection对象</returns>
public static SqlConnection init()
{
try
{
conn = new SqlConnection(connstr);
if (conn.State != ConnectionState.Open)
{
conn.Open();
}
}
catch (Exception e)
{
throw new Exception(e.Message.ToString());
}
return conn;
}
#endregion
#region 设置SqlCommand对象
/// <summary>
/// 设置SqlCommand对象
/// </summary>
/// <param name="cmd">SqlCommand对象 </param>
/// <param name="cmdText">命令文本</param>
/// <param name="cmdType">命令类型</param>
/// <param name="cmdParms">参数集合</param>
private static void SetCommand(SqlCommand cmd, string cmdText, CommandType cmdType, SqlParameter[] cmdParms)
{
cmd.Connection = conn;
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
if (cmdParms != null)
{
cmd.Parameters.AddRange(cmdParms);
}
}
#endregion
#region 执行相应的sql语句，返回相应的DataSet对象
/// <summary>
/// 执行相应的sql语句，返回相应的DataSet对象
/// </summary>
/// <param name="sqlstr">sql语句</param>
/// <returns>返回相应的DataSet对象</returns>
public static DataSet GetDataSet(string sqlstr)
{
DataSet set = new DataSet();
try
{
init();
SqlDataAdapter adp = new SqlDataAdapter(sqlstr, conn);
adp.Fill(set);
conn.Close();
}
catch (Exception e)
{
throw new Exception(e.Message.ToString());
}
return set;
}
#endregion
#region 执行相应的sql语句，返回相应的DataSet对象
/// <summary>
/// 执行相应的sql语句，返回相应的DataSet对象
/// </summary>
/// <param name="sqlstr">sql语句</param>
/// <param name="tableName">表名</param>
/// <returns>返回相应的DataSet对象</returns>
public static DataSet GetDataSet(string sqlstr, string tableName)
{
DataSet set = new DataSet();
try
{
init();
SqlDataAdapter adp = new SqlDataAdapter(sqlstr, conn);
adp.Fill(set, tableName);
conn.Close();
}
catch (Exception e)
{
throw new Exception(e.Message.ToString());
}
return set;
}
#endregion
#region 执行不带参数sql语句，返回所影响的行数
/// <summary>
/// 执行不带参数sql语句，返回所影响的行数
/// </summary>
/// <param name="cmdstr">增，删，改sql语句</param>
/// <returns>返回所影响的行数</returns>
public static int ExecuteNonQuery(string cmdText)
{
int count;
try
{
init();
cmd = new SqlCommand(cmdText, conn);
count = cmd.ExecuteNonQuery();
conn.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return count;
}
#endregion
#region 执行带参数sql语句或存储过程，返回所影响的行数
/// <summary>
/// 执行带参数sql语句或存储过程，返回所影响的行数
/// </summary>
/// <param name="cmdText">带参数的sql语句和存储过程名</param>
/// <param name="cmdType">命令类型</param>
/// <param name="cmdParms">参数集合</param>
/// <returns>返回所影响的行数</returns>
public static int ExecuteNonQuery(string cmdText, CommandType cmdType, SqlParameter[] cmdParms)
{
int count;
try
{
init();
cmd = new SqlCommand();
SetCommand(cmd, cmdText, cmdType, cmdParms);
count = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
conn.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return count;
}
#endregion
#region 执行不带参数sql语句，返回一个从数据源读取数据的SqlDataReader对象
/// <summary>
/// 执行不带参数sql语句，返回一个从数据源读取数据的SqlDataReader对象
/// </summary>
/// <param name="cmdstr">相应的sql语句</param>
/// <returns>返回一个从数据源读取数据的SqlDataReader对象</returns>
public static SqlDataReader ExecuteReader(string cmdText)
{
SqlDataReader reader;
try
{
init();
cmd = new SqlCommand(cmdText, conn);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return reader;
}
#endregion
#region 执行带参数的sql语句或存储过程，返回一个从数据源读取数据的SqlDataReader对象
/// <summary>
/// 执行带参数的sql语句或存储过程，返回一个从数据源读取数据的SqlDataReader对象
/// </summary>
/// <param name="cmdText">sql语句或存储过程名</param>
/// <param name="cmdType">命令类型</param>
/// <param name="cmdParms">参数集合</param>
/// <returns>返回一个从数据源读取数据的SqlDataReader对象</returns>
public static SqlDataReader ExecuteReader(string cmdText, CommandType cmdType, SqlParameter[] cmdParms)
{
SqlDataReader reader;
try
{
init();
cmd = new SqlCommand();
SetCommand(cmd, cmdText, cmdType, cmdParms);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return reader;
}
#endregion
#region 执行不带参数sql语句，返回一个DataTable对象
/// <summary>
/// 执行不带参数sql语句，返回一个DataTable对象
/// </summary>
/// <param name="cmdText">相应的sql语句</param>
/// <returns>返回一个DataTable对象</returns>
public static DataTable GetDataTable(string cmdText)
{
SqlDataReader reader;
DataTable dt=new DataTable();
try
{
init();
cmd = new SqlCommand(cmdText, conn);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
dt.Load(reader);
reader.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return dt;
}
#endregion
#region 执行带参数的sql语句或存储过程，返回一个DataTable对象
/// <summary>
/// 执行带参数的sql语句或存储过程，返回一个DataTable对象
/// </summary>
/// <param name="cmdText">sql语句或存储过程名</param>
/// <param name="cmdType">命令类型</param>
/// <param name="cmdParms">参数集合</param>
/// <returns>返回一个DataTable对象</returns>
public static DataTable GetDataTable(string cmdText, CommandType cmdType, SqlParameter[] cmdParms)
{
SqlDataReader reader;
DataTable dt=new DataTable();
try
{
init();
cmd = new SqlCommand();
SetCommand(cmd, cmdText, cmdType, cmdParms);
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
dt.Load(reader);
reader.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return dt;
}
#endregion
#region 执行不带参数sql语句,返回结果集首行首列的值object
/// <summary>
/// 执行不带参数sql语句,返回结果集首行首列的值object
/// </summary>
/// <param name="cmdstr">相应的sql语句</param>
/// <returns>返回结果集首行首列的值object</returns>
public static object ExecuteScalar(string cmdText)
{
object obj;
try
{
init();
cmd = new SqlCommand(cmdText, conn);
obj = cmd.ExecuteScalar();
conn.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return obj;
}
#endregion
#region 执行带参数sql语句或存储过程,返回结果集首行首列的值object
/// <summary>
/// 执行带参数sql语句或存储过程,返回结果集首行首列的值object
/// </summary>
/// <param name="cmdText">sql语句或存储过程名</param>
/// <param name="cmdType">命令类型</param>
/// <param name="cmdParms">返回结果集首行首列的值object</param>
/// <returns></returns>
public static object ExecuteScalar(string cmdText, CommandType cmdType, SqlParameter[] cmdParms)
{
object obj;
try
{
init();
cmd = new SqlCommand();
SetCommand(cmd, cmdText, cmdType, cmdParms);
obj = cmd.ExecuteScalar();
conn.Close();
}
catch (Exception ex)
{
throw new Exception(ex.Message.ToString());
}
return obj;
}
#endregion
}
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