- 修复 Ado.Query 查询字段重复时报错；#162 #165 #161 - 增加 FreeSql.Provider.MsAccess 支持 Access 数据库操作，已通过 2003/2007 版本测试；

Providers/FreeSql.Provider.MsAccess/MsAccessAdo/MsAccessAdo.cs

@@ -0,0 +1,77 @@
+using FreeSql.Internal;
+using FreeSql.Internal.Model;
+using SafeObjectPool;
+using System;
+using System.Collections;
+using System.Data.Common;
+using System.Data.OleDb;
+using System.Linq;
+using System.Text;
+using System.Threading;
+
+namespace FreeSql.MsAccess
+{
+    class MsAccessAdo : FreeSql.Internal.CommonProvider.AdoProvider
+    {
+        public MsAccessAdo() : base(DataType.MsAccess) { }
+        public MsAccessAdo(CommonUtils util, string masterConnectionString, string[] slaveConnectionStrings, Func<DbConnection> connectionFactory) : base(DataType.MsAccess)
+        {
+            base._util = util;
+            if (connectionFactory != null)
+            {
+                MasterPool = new FreeSql.Internal.CommonProvider.DbConnectionPool(DataType.MsAccess, connectionFactory);
+                return;
+            }
+            if (!string.IsNullOrEmpty(masterConnectionString))
+                MasterPool = new MsAccessConnectionPool("主库", masterConnectionString, null, null);
+            if (slaveConnectionStrings != null)
+            {
+                foreach (var slaveConnectionString in slaveConnectionStrings)
+                {
+                    var slavePool = new MsAccessConnectionPool($"从库{SlavePools.Count + 1}", slaveConnectionString, () => Interlocked.Decrement(ref slaveUnavailables), () => Interlocked.Increment(ref slaveUnavailables));
+                    SlavePools.Add(slavePool);
+                }
+            }
+        }
+
+        public override object AddslashesProcessParam(object param, Type mapType, ColumnInfo mapColumn)
+        {
+            if (param == null) return "NULL";
+            if (mapType != null && mapType != param.GetType() && (param is IEnumerable == false || mapType.IsArrayOrList()))
+                param = Utils.GetDataReaderValue(mapType, param);
+            if (param is bool || param is bool?)
+                return (bool)param ? -1 : 0;
+            else if (param is string || param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is Enum)
+                return ((Enum)param).ToInt64();
+            else if (decimal.TryParse(string.Concat(param), out var trydec))
+                return param;
+            else if (param is DateTime || param is DateTime?)
+            {
+                if (param.Equals(DateTime.MinValue) == true) param = new DateTime(1970, 1, 1);
+                return string.Concat("'", ((DateTime)param).ToString("yyyy-MM-dd HH:mm:ss"), "'");
+            }
+            else if (param is TimeSpan || param is TimeSpan?)
+                return ((TimeSpan)param).TotalSeconds;
+            else if (param is IEnumerable) 
+                return AddslashesIEnumerable(param, mapType, mapColumn);
+
+            return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+        }
+
+        protected override DbCommand CreateCommand()
+        {
+            return new OleDbCommand();
+        }
+
+        protected override void ReturnConnection(IObjectPool<DbConnection> pool, Object<DbConnection> conn, Exception ex)
+        {
+            var rawPool = pool as MsAccessConnectionPool;
+            if (rawPool != null) rawPool.Return(conn, ex);
+            else pool.Return(conn);
+        }
+
+        protected override DbParameter[] GetDbParamtersByObject(string sql, object obj) => _util.GetDbParamtersByObject(sql, obj);
+    }
+}