private DeleteStatement BuildSlave(TableDefinition master, IEntityMetadata entity)
{
var statement = new DeleteStatement(entity);
var reference = TableIdentifier.Temporary(master.Name, TEMPORARY_ALIAS);
if (entity.Key.Length == 1)
{
var select = new SelectStatement(reference);
select.Select.Members.Add(reference.CreateField(master.Fields.First().Name));
statement.Where = Expression.In(statement.Table.CreateField(entity.Key[0]), select);
}
else
{
var join = new JoinClause(TEMPORARY_ALIAS, reference, JoinType.Inner);
foreach (var key in entity.Key)
{
join.Condition.Add(
Expression.Equal(
statement.Table.CreateField(key),
reference.CreateField(key)));
}
statement.From.Add(join);
}
master.Slaves.Add(statement);
return(statement);
}
private TableDefinition BuildMaster(DeleteStatement statement, IEnumerable <SchemaMember> schemas)
{
var master = TableDefinition.Temporary();
master.Slaves.Add(statement);
statement.Returning = new ReturningClause(TableIdentifier.Temporary(master.Name));
foreach (var key in statement.Entity.Key)
{
master.Field(key);
statement.Returning.Fields.Add(statement.Table.CreateField(key));
}
var super = statement.Entity.GetBaseEntity();
while (super != null)
{
this.BuildSlave(master, super);
super = super.GetBaseEntity();
}
if (schemas != null)
{
foreach (var schema in schemas)
{
if (schema.Token.Property.IsSimplex)
{
continue;
}
var complex = (IEntityComplexPropertyMetadata)schema.Token.Property;
ISource src = null;
if (complex.Entity == statement.Entity)
{
src = statement.Table;
}
else
{
src = statement.Join(statement.Table, complex.Entity);
}
foreach (var link in complex.Links)
{
//某些导航属性可能与主键相同，表定义的字段定义方法（TableDefinition.Field(...)）可避免同名字段的重复定义
if (master.Field(link.Principal) != null)
{
statement.Returning.Fields.Add(src.CreateField(link.Name));
}
}
this.BuildSlave(master, schema);
}
}
return(master);
}
private DeleteStatement BuildSlave(TableDefinition master, SchemaMember schema)
{
var complex = (IEntityComplexPropertyMetadata)schema.Token.Property;
var statement = new DeleteStatement(complex.Foreign);
var reference = TableIdentifier.Temporary(master.Name, TEMPORARY_ALIAS);
if (complex.Links.Length == 1)
{
var select = new SelectStatement(reference);
select.Select.Members.Add(reference.CreateField(complex.Links[0].Name));
statement.Where = Expression.In(statement.Table.CreateField(complex.Links[0].Role), select);
}
else
{
var join = new JoinClause(TEMPORARY_ALIAS, reference, JoinType.Inner);
foreach (var link in complex.Links)
{
join.Condition.Add(
Expression.Equal(
statement.Table.CreateField(link.Role),
reference.CreateField(link.Name)));
}
statement.From.Add(join);
}
var super = statement.Entity.GetBaseEntity();
if (super != null || schema.HasChildren)
{
var temporary = this.BuildMaster(statement, schema.Children);
master.Slaves.Add(temporary);
//if(schema.HasChildren)
//{
// foreach(var child in schema.Children)
// {
// this.BuildSlave(temporary, child);
// }
//}
}
else
{
master.Slaves.Add(statement);
}
return(statement);
}
