private TableIdentifier Join(Aliaser aliaser, UpdateStatement statement, SchemaMember schema)
{
if (schema == null || schema.Token.Property.IsSimplex)
{
return(null);
}
//获取关联的源
ISource source = schema.Parent == null ?
statement.Table :
statement.From.Get(schema.Path);
//第一步：处理模式成员所在的继承实体的关联
if (schema.Ancestors != null)
{
foreach (var ancestor in schema.Ancestors)
{
source = statement.Join(aliaser, source, ancestor, schema.FullPath);
}
}
//第二步：处理模式成员（导航属性）的关联
var join = statement.Join(aliaser, source, schema);
var target = (TableIdentifier)join.Target;
statement.Tables.Add(target);
//返回关联的目标表
return(target);
}
private void BuildComplexStandalone(DataUpdateContext context, UpdateStatement statement, object data, SchemaMember member)
{
if (!member.HasChildren)
{
return;
}
var complex = (IDataEntityComplexProperty)member.Token.Property;
statement.Returning = new ReturningClause(TableDefinition.Temporary());
var slave = new UpdateStatement(complex.Foreign, member);
statement.Slaves.Add(slave);
//创建从属更新语句的条件子查询语句
var selection = new SelectStatement(statement.Returning.Table.Identifier());
foreach (var link in complex.Links)
{
ISource source = statement.Table;
foreach (var anchor in link.GetAnchors())
{
if (anchor.IsComplex)
{
source = statement.Join(context.Aliaser, source, (IDataEntityComplexProperty)anchor);
}
else
{
if (statement.Returning.Table.Field((IDataEntitySimplexProperty)anchor) != null)
{
statement.Returning.Append(source.CreateField(anchor.Name), ReturningClause.ReturningMode.Deleted);
}
var field = selection.Table.CreateField(anchor);
selection.Select.Members.Add(field);
if (selection.Where == null)
{
selection.Where = Expression.Equal(field, slave.Table.CreateField(link.ForeignKey));
}
else
{
selection.Where = Expression.AndAlso(slave.Where,
Expression.Equal(field, slave.Table.CreateField(link.ForeignKey)));
}
}
}
}
slave.Where = Expression.Exists(selection);
foreach (var child in member.Children)
{
this.BuildSchema(context, slave, slave.Table, member.Token.GetValue(data), child);
}
}