Esempio n. 1
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 internal FromExpression(EngineType engineType)
 {
     _expressionContext = new SQLExpressionVisitorContenxt(engineType)
     {
         ParamPlaceHolderPrefix = SqlHelper.ParameterizedChar + "f__"
     };
 }
Esempio n. 2
0
        private static object VisitLambda(LambdaExpression lambda, SQLExpressionVisitorContenxt context)
        {
            if (lambda.Body.NodeType == ExpressionType.MemberAccess && context.Seperator == " ")
            {
                MemberExpression m = (MemberExpression)lambda.Body;

                if (m.Expression != null)
                {
                    object r = VisitMemberAccess(m, context);

                    if (!(r is PartialSqlString))
                    {
                        return(r);
                    }

                    if (!m.Expression.Type.IsValueType)
                    {
                        return(r.ToString() !);
                    }

                    //return $"{r}={context.DatabaesEngine.GetDbValueStatement(true, needQuoted: true)}";
                    return($"{r}=1");
                }
            }
            return(Visit(lambda.Body, context));
        }
Esempio n. 3
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        private static object VisitBinary(BinaryExpression b, SQLExpressionVisitorContenxt context)
        {
            object left;
            object right;
            bool   rightIsNull;
            string operand = BindOperant(b.NodeType);

            if (operand == "AND" || operand == "OR")
            {
                if (b.Left is MemberExpression m && m.Expression != null && m.Expression.NodeType == ExpressionType.Parameter)
                {
                    //left = new PartialSqlString(string.Format(GlobalSettings.Culture, "{0}={1}", VisitMemberAccess(m, context), context.DatabaesEngine.GetDbValueStatement(true, needQuoted: true)));
                    left = new PartialSqlString($"{VisitMemberAccess(m, context)}=1");
                }
                else
                {
                    left = Visit(b.Left, context);
                }

                if (b.Right is MemberExpression mm && mm.Expression != null && mm.Expression.NodeType == ExpressionType.Parameter)
                {
                    right = new PartialSqlString($"{VisitMemberAccess(mm, context)}=1");
                }
Esempio n. 4
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        public static object Visit(Expression?exp, SQLExpressionVisitorContenxt context)
        {
            if (exp == null)
            {
                return(string.Empty);
            }

            switch (exp.NodeType)
            {
            case ExpressionType.Lambda:
                return(VisitLambda((LambdaExpression)exp, context));

            case ExpressionType.MemberAccess:
                return(VisitMemberAccess((MemberExpression)exp, context));

            case ExpressionType.Constant:
                return(VisitConstant((ConstantExpression)exp));

            case ExpressionType.Add:
            case ExpressionType.AddChecked:
            case ExpressionType.Subtract:
            case ExpressionType.SubtractChecked:
            case ExpressionType.Multiply:
            case ExpressionType.MultiplyChecked:
            case ExpressionType.Divide:
            case ExpressionType.Modulo:
            case ExpressionType.And:
            case ExpressionType.AndAlso:
            case ExpressionType.Or:
            case ExpressionType.OrElse:
            case ExpressionType.LessThan:
            case ExpressionType.LessThanOrEqual:
            case ExpressionType.GreaterThan:
            case ExpressionType.GreaterThanOrEqual:
            case ExpressionType.Equal:
            case ExpressionType.NotEqual:
            case ExpressionType.Coalesce:
            case ExpressionType.ArrayIndex:
            case ExpressionType.RightShift:
            case ExpressionType.LeftShift:
            case ExpressionType.ExclusiveOr:
                return(VisitBinary((BinaryExpression)exp, context));

            case ExpressionType.Negate:
            case ExpressionType.NegateChecked:
            case ExpressionType.Not:
            case ExpressionType.Convert:
            case ExpressionType.ConvertChecked:
            case ExpressionType.ArrayLength:
            case ExpressionType.Quote:
            case ExpressionType.TypeAs:
                return(VisitUnary((UnaryExpression)exp, context));

            case ExpressionType.Parameter:
                return(VisitParameter((ParameterExpression)exp));

            case ExpressionType.Call:
                return(VisitMethodCall((MethodCallExpression)exp, context));

            case ExpressionType.New:
                return(VisitNew((NewExpression)exp, context));

            case ExpressionType.NewArrayInit:
            case ExpressionType.NewArrayBounds:
                return(VisitNewArray((NewArrayExpression)exp, context));

            case ExpressionType.MemberInit:
                return(VisitMemberInit((MemberInitExpression)exp));

            default:
                return(exp.ToString());
            }
        }