using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Text;
namespace DAL
{
public class DBhelper
{
private static string DBConnectString = "Data Source=.;Initial Catalog=asp.net6;Integrated Security=True";
private static SqlConnection conn;
private static SqlDataAdapter da;
private static SqlDataReader dr;
private static SqlCommand cmd;
private static DBhelper dBHelper;
public DBhelper()
{
conn = new SqlConnection(DBConnectString);
}
public static DBhelper Instance()
{
if (dBHelper == null)
{
dBHelper = new DBhelper();
}
return dBHelper;
}
void DBOpen()
{
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
}
void DBClose()
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
}
}
/// <summary>
/// 执行查询（SELECT）
/// </summary>
/// <param name="sql">查询语句</param>
/// <returns>包含数据库数据的DataTable对象</returns>
public DataTable GetDataTableBySql(string sql)
{
DBOpen();
DataTable dt = new DataTable();
da = new SqlDataAdapter(sql, conn);
try
{
da.Fill(dt);
return dt;
}
catch
{
return null;
}
finally
{
DBClose();
}
}
/// <summary>
/// 执行查询（SELECT）
/// </summary>
/// <param name="sql">查询语句</param>
/// <returns>用于检索数据库数据的读取器SqlDataReader对象</returns>
public SqlDataReader GetDataReaderBySql(string sql)
{
DBOpen();
cmd = new SqlCommand(sql, conn);
try
{
dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
return dr;
}
catch
{
return null;
}
}
/// <summary>
/// 执行增、删、改（INSERT、DELETE、UPDATE）
/// </summary>
/// <param name="sql">查询语句</param>
/// <returns>操作成功与否</returns>
public bool ExcuteSql(string sql)
{
DBOpen();
cmd = new SqlCommand(sql, conn);
try
{
cmd.ExecuteNonQuery();
return true;
}
catch
{
return false;
}
finally
{
DBClose();
}
}
/// <summary>
/// 执行存储过程
/// </summary>
/// <param name="proName">存储过程名</param>
/// <param name="paras">存储过程参数</param>
/// <returns>操作成功与否</returns>
public bool ExcuteProcedure(string proName, SqlParameter[] paras)
{
DBOpen();
cmd = new SqlCommand(proName, conn);
cmd.CommandType = CommandType.StoredProcedure;
for (int i = 0; i < paras.Length; i++)
{
cmd.Parameters.Add(paras[i]);
}
try
{
if (cmd.ExecuteNonQuery() > 0)
{
return true;
}
else
{
return false;
}
}
catch
{
return false;
}
finally
{
DBClose();
}
}
}
}
