Support custom database

Src/Asp.Net/SqlSugar/Enum/DbType.cs

@@ -14,6 +14,9 @@ namespace SqlSugar
         PostgreSQL,
         Dm,
         Kdbndp,
-        Oscar
+        Oscar,
+        MySqlConnector,
+        Access,
+        Custom=900
     }
 }

Src/Asp.Net/SqlSugar/Infrastructure/InstanceFactory.cs

@@ -33,6 +33,18 @@ namespace SqlSugar
             {
                 return new PostgreSQLQueryable<T>();
             } 
+            else if (currentConnectionConfig.DbType == DbType.MySqlConnector) 
+            {
+                return CustomProvider.GetQueryable<T>("MySql", "SqlSugar.MySqlConnector");
+            }
+            else if (currentConnectionConfig.DbType == DbType.Access)
+            {
+                return CustomProvider.GetQueryable<T>("MySql", "SqlSugar.Access");
+            }
+            else if (currentConnectionConfig.DbType == DbType.Custom)
+            {
+                return CustomProvider.GetQueryable<T>("DbType.Custom", "DbType.Custom");
+            }
             else
             {
                 string className = "Queryable";

Src/Asp.Net/SqlSugar/Realization/Custom/CustomProvider.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SqlSugar 
+{
+    public class CustomProvider
+    {
+        internal static ISugarQueryable<T> GetQueryable<T>(string dbName, string dllName)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

Src/Asp.Net/SqlSugar/SqlSugar.csproj

@@ -102,6 +102,7 @@
     <Compile Include="Interface\IFastBuilder.cs" />
     <Compile Include="Interface\IFastest.cs" />
     <Compile Include="OnlyNet\OracleFastBuilder.cs" />
+    <Compile Include="Realization\Custom\CustomProvider.cs" />
     <Compile Include="Realization\MySql\SqlBuilder\MySqlFastBuilder.cs" />
     <Compile Include="Realization\PostgreSQL\SqlBuilder\PostgreSQLFastBuilder.cs" />
     <Compile Include="Realization\Sqlite\SqlBuilder\SqliteFastBuilder.cs" />