SqlSugar可同時連接多種類數據庫的 daonet框架

1、官方中文文檔

https://www.donet5.com/home/Doc

2、引入NuGet包

3、數據庫訪問類

using SqlSugar;
using System.Configuration;
using log4net;

namespace Dao
{
    public class SqlGenerator
    {
        private static readonly ILog log = LogManager.GetLogger(typeof(SqlGenerator));
        public static string ConnectionString = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;

        private static SqlSugarClient sqlSugarClient = null;

        private static readonly object lockHelper = new object();

        /// <summary>
        /// 連接Oracle數據庫
        /// </summary>
        /// <returns></returns>
        public static SqlSugarClient GetOracleInstance()
        {
            if (sqlSugarClient == null)
            {
                lock (lockHelper)
                {   
　　　　　　　　　　　　//此寫法，官方不推薦
                    //單例模式，避免多次實例化
                    if (sqlSugarClient == null) { sqlSugarClient = new SqlSugarClient(new ConnectionConfig()
                        {
                            //數據庫類型
                            DbType = DbType.Oracle,
                            //數據庫連接字符串
                            ConnectionString = ConnectionString,
                            InitKeyType = InitKeyType.Attribute,
                            //是否自動關閉連接
                            IsAutoCloseConnection = true,
                            AopEvents = new AopEvents
                            {
                                //記錄執行SQL和參數
                                OnLogExecuting = (sql, p) =>
                                {
                                    log.Debug(sql);
                                }
                            }
                        });
                    }
                }

            }
            return sqlSugarClient;
        }

        //官方建議 不單例 SqlSugarClient 對象
        public SqlSugarClient GetSQLServerInstance()
        {
            return new SqlSugarClient(new ConnectionConfig()
                        {
                            DbType = DbType.SqlServer,
                            ConnectionString = ConnectionString,
                            InitKeyType = InitKeyType.Attribute,
                            IsAutoCloseConnection = true,
                            AopEvents = new AopEvents
                            {
                                OnLogExecuting = (sql, p) =>
                                {
                                    log.Debug(sql);
                                }
                            }
                        });
        }

    }
}

4、使用

//獲取數據訪問類對象
SqlSugarClient sqlServerDB = SqlGenerator.GetSQLServerInstance();

//調用查詢方法
sqlServerDB.Ado.SqlQuery<CommonTable>(sql).ToList();

5、增、刪、改 及查詢更多更詳細的方法，請參照官方幫助文檔

https://www.donet5.com/home/Doc

https://www.donet5.com

6、在sqlSugar的幫助類中盡量避免  單例 SqlSugarClient ，也就是上述代碼中的 紅色部分，官方是不建議使用單例對象的，具體原因是：

偶發性錯誤 - SqlSugar 5x - .NET果糖網 (donet5.com)

在多線程下，可能會引發異常。