using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace Ant.Common
{
    public static class UtilConstants
    {
        public const string DefaultTableAlias = "T";
        public const string DefaultColumnAlias = "C";

        public static readonly Type TypeOfVoid = typeof(void);
        public static readonly Type TypeOfInt16 = typeof(Int16);
        public static readonly Type TypeOfInt32 = typeof(Int32);
        public static readonly Type TypeOfInt64 = typeof(Int64);
        public static readonly Type TypeOfDecimal = typeof(Decimal);
        public static readonly Type TypeOfDouble = typeof(Double);
        public static readonly Type TypeOfSingle = typeof(Single);
        public static readonly Type TypeOfBoolean = typeof(Boolean);
        public static readonly Type TypeOfBoolean_Nullable = typeof(Boolean?);
        public static readonly Type TypeOfDateTime = typeof(DateTime);
        public static readonly Type TypeOfGuid = typeof(Guid);
        public static readonly Type TypeOfByte = typeof(Byte);
        public static readonly Type TypeOfChar = typeof(Char);
        public static readonly Type TypeOfString = typeof(String);
        public static readonly Type TypeOfObject = typeof(Object);
        public static readonly Type TypeOfByteArray = typeof(Byte[]);


        public static readonly Type TypeOfIntNull16 = typeof(Int16?);
        public static readonly Type TypeOfIntNull32 = typeof(Int32?);
        public static readonly Type TypeOfIntNull64 = typeof(Int64?);

        public static readonly ConstantExpression Constant_Null_Boolean = Expression.Constant(null, typeof(Boolean?));
        public static readonly ConstantExpression Constant_True = Expression.Constant(true);
        public static readonly ConstantExpression Constant_False = Expression.Constant(false);
        public static readonly UnaryExpression Convert_TrueToNullable = Expression.Convert(Expression.Constant(true), typeof(Boolean?));
        public static readonly UnaryExpression Convert_FalseToNullable = Expression.Convert(Expression.Constant(false), typeof(Boolean?));
    }
}