using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Threading.Tasks;
namespace BookShopDAL
{
/// <summary>
/// Sql辅助类==》用于操作数据库
/// </summary>
public class SqlHelper
{
/// <summary>
/// 连接字符串
/// </summary>
//private static readonly string connectionString = ConfigurationManager.ConnectionStrings["BookShopPlus"].ConnectionString;
private static readonly string connectionString = @"server=SERVERSQLEXPRESS;database=BookShopPlus;uid=sa;pwd=sa";
//private static readonly string connectionString = "server=.;database=BookShopPlus;uid=sa;pwd=sa";
/// <summary>
/// 获取连接
/// </summary>
private static SqlConnection _conn;
public static SqlConnection Conn
{
get
{
if (_conn == null) _conn = new SqlConnection(connectionString);
if (_conn.State == ConnectionState.Broken)
{
_conn.Close();
_conn.Open();
}
else if (_conn.State == ConnectionState.Closed)
{
_conn.Open();
}
return _conn;
}
}
/// <summary>
/// 关闭连接
/// </summary>
public static void CloseConnection()
{
if (Conn == null) return;
if (Conn.State == ConnectionState.Open || Conn.State == ConnectionState.Broken)
{
Conn.Close();
}
}
/// <summary>
/// 增删改
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="type">执行解析类型 默认 sql</param>
/// <param name="param">参数</param>
/// <returns></returns>
public static int ExecuteNonQuery(string sql, CommandType type = CommandType.Text, params SqlParameter[] param)
{
try
{
//创建执行对象
SqlCommand cmd = new SqlCommand(sql, Conn);
//判断是否存在参数
if (param != null && param.Length > 0)
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type;//指定解析类型
return cmd.ExecuteNonQuery();//返回执行后的结果
}
catch (Exception e)
{
throw e;
}
finally
{
CloseConnection();
}
}
/// <summary>
///
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="type">执行解析类型 默认 sql</param>
/// <param name="param">参数</param>
/// <returns>返回查询所返回的结果集中第一行的第一列</returns>
public static int ExecuteScalar(string sql, CommandType type = CommandType.Text, params SqlParameter[] param)
{
try
{
//创建执行对象
SqlCommand cmd = new SqlCommand(sql, Conn);
//判断是否存在参数
if (param != null && param.Length > 0)
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type;//指定解析类型
return (int)cmd.ExecuteScalar();//返回执行后的结果
}
catch (Exception e)
{
throw e;
}
finally
{
CloseConnection();
}
}
/// <summary>
/// 异步操作的任务查询
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="type">执行解析类型 默认 sql</param>
/// <param name="param">参数</param>
/// <returns>Task<SqlDataReader></returns>
public static Task<SqlDataReader> ExecuteReaderAsync(string sql, CommandType type = CommandType.Text, params SqlParameter[] param)
{
SqlCommand cmd = new SqlCommand(sql, Conn);
if (param != null && param.Length > 0)
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type;
return cmd.ExecuteReaderAsync();
}
/// <summary>
/// 查询
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="type">执行解析类型 默认 sql</param>
/// <param name="param">参数</param>
/// <returns>SqlDataReader</returns>
public static SqlDataReader ExecuteReader(string sql, CommandType type = CommandType.Text, params SqlParameter[] param)
{
SqlCommand cmd = new SqlCommand(sql, Conn);
if (param != null && param.Length > 0)
{
cmd.Parameters.AddRange(param);
}
cmd.CommandType = type;
return cmd.ExecuteReader();
}
/// <summary>
/// 查询(断开式连接)
/// </summary>
/// <param name="sql">sql语句</param>
/// <param name="type">执行解析类型 默认 sql</param>
/// <param name="param">参数</param>
/// <returns>DataTable</returns>
public static DataTable GetTable(string sql, CommandType type = CommandType.Text, params SqlParameter[] param)
{
DataSet ds = new DataSet();
SqlDataAdapter sda = new SqlDataAdapter(sql, Conn);
if (param != null && param.Length > 0)
{
sda.SelectCommand.Parameters.AddRange(param);
}
sda.SelectCommand.CommandType = type;
sda.Fill(ds);//填充数据到ds
return ds.Tables[0];
}
}
}