86 lines
3.3 KiB
C#
86 lines
3.3 KiB
C#
using System;
|
|
using System.Collections;
|
|
using System.Collections.Generic;
|
|
using System.Collections.ObjectModel;
|
|
using System.Linq.Expressions;
|
|
using System.Reflection;
|
|
using System.Text;
|
|
using System.Linq;
|
|
using System.Data.Linq.Mapping;
|
|
using System.Data.Linq.Provider;
|
|
|
|
namespace System.Data.Linq.SqlClient {
|
|
/// <summary>
|
|
/// This class defines the rules for inheritance behaviors. The rules:
|
|
///
|
|
/// (1) The same field may not be mapped to different database columns.
|
|
/// The DistinguishedMemberName and AreSameMember methods describe what 'same' means between two MemberInfos.
|
|
/// (2) Discriminators held in fixed-length fields in the database don't need
|
|
/// to be manually padded in inheritance mapping [InheritanceMapping(Code='x')].
|
|
///
|
|
/// </summary>
|
|
static class InheritanceRules {
|
|
/// <summary>
|
|
/// Creates a name that is the same when the member should be considered 'same'
|
|
/// for the purposes of the inheritance feature.
|
|
/// </summary>
|
|
internal static object DistinguishedMemberName(MemberInfo mi) {
|
|
PropertyInfo pi = mi as PropertyInfo;
|
|
FieldInfo fi = mi as FieldInfo;
|
|
if (fi != null) {
|
|
// Human readable variant:
|
|
// return "fi:" + mi.Name + ":" + mi.DeclaringType;
|
|
return new MetaPosition(mi);
|
|
}
|
|
else if (pi != null) {
|
|
MethodInfo meth = null;
|
|
|
|
if (pi.CanRead) {
|
|
meth = pi.GetGetMethod();
|
|
}
|
|
if (meth == null && pi.CanWrite) {
|
|
meth = pi.GetSetMethod();
|
|
}
|
|
bool isVirtual = meth != null && meth.IsVirtual;
|
|
|
|
// Human readable variant:
|
|
// return "pi:" + mi.Name + ":" + (isVirtual ? "virtual" : mi.DeclaringType.ToString());
|
|
|
|
if (isVirtual) {
|
|
return mi.Name;
|
|
} else {
|
|
return new MetaPosition(mi);
|
|
}
|
|
}
|
|
else {
|
|
throw Error.ArgumentOutOfRange("mi");
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Compares two MemberInfos for 'same-ness'.
|
|
/// </summary>
|
|
internal static bool AreSameMember(MemberInfo mi1, MemberInfo mi2) {
|
|
return DistinguishedMemberName(mi1).Equals(DistinguishedMemberName(mi2));
|
|
}
|
|
|
|
/// <summary>
|
|
/// The representation of a inheritance code when mapped to a specific provider type.
|
|
/// </summary>
|
|
internal static object InheritanceCodeForClientCompare(object rawCode, System.Data.Linq.SqlClient.ProviderType providerType) {
|
|
// If its a fixed-size string type in the store then pad it with spaces so that
|
|
// comparing the string on the client agrees with the value returnd on the store.
|
|
if (providerType.IsFixedSize && rawCode.GetType()==typeof(string)) {
|
|
string s = (string) rawCode;
|
|
if (providerType.Size.HasValue && s.Length!=providerType.Size) {
|
|
s = s.PadRight(providerType.Size.Value).Substring(0,providerType.Size.Value);
|
|
}
|
|
return s;
|
|
}
|
|
return rawCode;
|
|
}
|
|
|
|
|
|
}
|
|
}
|