Update exp to sql

Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubAnd.cs

@@ -41,7 +41,13 @@ namespace SqlSugar
         {
             var exp = expression as MethodCallExpression;
             var argExp = exp.Arguments[0];
-            var result = "AND " + SubTools.GetMethodValue(this.Context, argExp, ResolveExpressType.WhereMultiple);
+            var copyContext = this.Context;
+            if (this.Context.JoinIndex > 0) 
+            {
+                copyContext = this.Context.GetCopyContextWithMapping();
+                copyContext.IsSingle = false;
+            }
+            var result = "AND " + SubTools.GetMethodValue(copyContext, argExp, ResolveExpressType.WhereMultiple);
 
 
             var regex = @"^AND  (\@Const\d+) $";