Create Where Clause Dynamically For Byte? Field

Question

Related To: Create a Lambda Expression With 3 conditions

Exactly similar to above topic I wrote this Expression:

var body = Expression.AndAlso(
Expression.Equal(
    Expression.PropertyOrField(param, "Year"),
    Expression.Constant(year)
    ),
    Expression.AndAlso(
        Expression.Equal(
            Expression.PropertyOrField(param, "CityCode"),
            Expression.Constant(cityCode)
        ),
        Expression.Equal(
            Expression.PropertyOrField(param, "Status"),
            Expression.Constant(50)
        )
    )
);

the only different is in my new table Status is tinyint null or (byte?) in C#. When I run the code I got this error:

The binary operator Equal is not defined for the types 'System.Nullable`1[System.Byte]' and 'System.Byte'

so I change Expression.Constant(50) to Expression.Constant((byte?)50) and again got the same error. Where is my mistake?

Thanks

Update 1)

I tried this: Expression.Constant(50, typeof(byte?)); but I got this error:

Argument types do not match

@Arian It is not possible. Since you do not have any exception handlers here, once first method call throw the exception, other method calls will not be done. So that exactly one method call throw the exception. Which one? — user4003407, Apr 27 '19 at 13:21

score 1 · Accepted Answer · answered Apr 27 '19 at 12:53

1

Almost as Evan said:

Expression.Constant((byte?)50, typeof(byte?))

answered Apr 27 '19 at 12:53

Metheny

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Create Where Clause Dynamically For Byte? Field

1 Answers1