private DbExpression GetMemberExpressionByPath(TranslationContext context, DbUnitItemTypeExpression item, string path)
{
if (string.IsNullOrEmpty(path))
{
throw new ArgumentNullException(Res.ExceptionMemberPathCannotEmpty, nameof(path));
}
var paths = path.Split('.');
var metadata = context.Context.Configuration.Metadata;
DbExpression current = null;
NavigateMetadata navigate = null;
for (var i = 0; i < paths.Length; i++)
{
var table = current == null?metadata.Table(item.ClrType) : navigate.Target;
var navikeyvalue = table.Navigates.Where(a => a.Key.Name == paths[i]).FirstOrDefault();
var propertyinfo = navikeyvalue.Key as PropertyInfo;
if (propertyinfo == null)
{
throw new KeyNotFoundException(Res.ExceptionNotFoundNavigateKey);
}
if (propertyinfo.PropertyType.IsComplexCollection() && i != paths.Length - 1)
{
throw new ArgumentException(Res.ExceptionCollectionMemberLevelError);
}
current = CreateMemberExpression(context, propertyinfo, current == null ? item : current);
navigate = navikeyvalue.Value;
}
return(current);
}
/// <summary>
/// 初始化导航元数据及关系信息。
/// </summary>
/// <param name="metadata">导航元数据。</param>
/// <param name="parent">父级表达式。</param>
private void InitialNavigate(NavigateMetadata metadata, DbExpression parent)
{
Metadata = metadata;
TargetSet = new DbDataSetExpression(typeof(IEnumerable <>).MakeGenericType(metadata.Target.ClrType));
var comNavi = metadata as CompositeNavigateMetadata;
if (comNavi != null)
{
RelationSet = new DbDataSetExpression(typeof(IEnumerable <>).MakeGenericType(comNavi.RelationTable.ClrType));
Pairs = comNavi.Pairs.Select(a =>
{
var left = new DbMemberExpression(a.ForeignKey.Member, RelationSet);
var right = new DbMemberExpression(a.PrincipalKey.Member, parent);
return(new DbJoinKeyPairExpression(left, right));
}).ToArray();
CompositePairs = comNavi.CompositePairs.Select(a =>
{
var left = new DbMemberExpression(a.PrincipalKey.Member, TargetSet);
var right = new DbMemberExpression(a.ForeignKey.Member, RelationSet);
return(new DbJoinKeyPairExpression(left, right));
}).ToArray();
}
else
{
Pairs = metadata.Pairs.Select(a =>
{
var left = new DbMemberExpression(a.ForeignKey.Member, parent);
var right = new DbMemberExpression(a.PrincipalKey.Member, TargetSet);
return(new DbJoinKeyPairExpression(left, right));
}).ToArray();
}
Nullable = Metadata.Pairs.Select(a => a.ForeignKey.Member)
.OfType <PropertyInfo>().All(a => a.PropertyType.IsNullable());
}
/// <summary>
/// 创建关系操作基类。
/// </summary>
/// <param name="context">数据上下文。</param>
/// <param name="member">关系导航属性。</param>
/// <param name="type">目标数据类型。</param>
/// <param name="table">当前数据表元数据。</param>
/// <param name="navigate">当前关系元数据。</param>
internal DbRelationOperateBase(DbContext context, PropertyInfo member, Type type, TableMetadata table, NavigateMetadata navigate)
: base(context, type, null)
{
Member = member;
Table = table;
Navigate = navigate;
_ItemParameterCount = Navigate.Source.Keys.Length + Navigate.Target.Keys.Length;
}
/// <summary>
/// 添加关系操作。
/// </summary>
/// <param name="context">数据上下文。</param>
/// <param name="member">成员CLR描述对象。</param>
/// <param name="type">相关源类型。</param>
/// <param name="table">相关表元数据。</param>
/// <param name="navigate">相关导航元数。</param>
internal DbAddRelationOperate(DbContext context, PropertyInfo member, Type type, TableMetadata table, NavigateMetadata navigate)
: base(context, member, type, table, navigate)
{
}