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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.OleDb;
using System.Windows.Forms;
using System.Configuration;
namespace EmployeeManage
{
public class DBHelper
{
//属性:数据库链接对象
private static OleDbConnection conn;
public static OleDbConnection Conn
{
get
{
try
{
string connstr ="Data Source=.;Initial Catalog=Data;User ID=sa;Password=123456";//ConfigurationManager.ConnectionStrings["DatabaseConnStr"].ConnectionString.ToString();
if (conn == null)
conn = new OleDbConnection(connstr);
if (conn.State == ConnectionState.Closed)
conn.Open();
if (conn.State == ConnectionState.Broken)
{
conn.Close();
conn.Open();
}
return conn;
}
catch (Exception ex)
{
throw;
}
}
}
//方法:查询,DataReader
public static OleDbDataReader GetReader(string SqlStr)
{
OleDbCommand cmd = new OleDbCommand(SqlStr, Conn);
return cmd.ExecuteReader();
}
public static OleDbDataReader GetReader(string SqlStr, OleDbParameter[] paras)
{
OleDbCommand cmd = new OleDbCommand(SqlStr, Conn);
cmd.Parameters.AddRange(paras);
return cmd.ExecuteReader();
}
//查询:DataTable
public static DataTable GetTable(string SqlStr)
{
try
{
OleDbDataAdapter dap = new OleDbDataAdapter(SqlStr, Conn);
DataSet ds = new DataSet();
dap.Fill(ds);
conn.Close();
return ds.Tables[0];
}
catch (Exception ex)
{
throw;
}
}
//增删改
public static bool Execute(string SqlStr)
{
OleDbCommand cmd = new OleDbCommand(SqlStr, Conn);
int result = cmd.ExecuteNonQuery();
conn.Close();
return result > 0;
}
//返回首行首列
public static object GetScalar(string SqlStr)
{
OleDbCommand cmd = new OleDbCommand(SqlStr, Conn);
object obj = cmd.ExecuteScalar();
conn.Close();
return obj;
}
/// <summary>
/// 执行多条SQL语句,实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static void ExecuteSqlTran(List<string> SQLStringList)
{
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = Conn;
OleDbTransaction tx = Conn.BeginTransaction();
cmd.Transaction = tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch (System.Data.OleDb.OleDbException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
}
string sql=select a.系统代码,a.文件编号,a.条,a.款,a.顶,a.thetext from Bas_law a left out join
Bas_illegal b on a.系统代码=b.thekey where b.illegalid='"+Id+"'