private void GenerateForInsertReturnStatement(GenerateContext context,
BlockFragment block, ISourceFragment target, TemporaryTableFragment temptable)
{
var data = (GenerateDataForInsert)context.Data;
if (data.ReturnMembers.Any())
{
if (data.SubUnits != null)
{
target = new InheritFragment(context, data.Table);
}
var select = new SelectFragment(context, target);
select.Members.AddRange(data.ReturnMembers.Select(a => target.GetMember(a.Metadata)));
if (temptable == null)
{
select.Where = target.JoinCondition(data.CommitObject, data.Table.Keys);
}
else
{
var datatable = temptable.Clone();
select.AddSource(datatable);
target.Join(datatable, data.Table.Keys);
}
block.Add(select);
}
}
/// <summary>
/// 使用临时表形式，生成更新若干数据对象语句，
/// 要求数据库拥有<see cref="EDbCapable.TemporaryTable"/>
/// 和<see cref="EDbCapable.ModifyJoin"/>两个特性
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="content">更新表达式。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForUpdateTempTable(GenerateContext context, DbExpression content)
{
var data = (GenerateDataForUpdate)context.Data;
var name = data.TargetName;
var block = new BlockFragment(context);
UpdateFragment mainUpdate = null;
TemporaryTableFragment temptable = null;
var members = data.GetTables().SelectMany(a => a.Members);
foreach (var unit in data.GetUnits())
{
TemporaryTableFragment current = null;
if (temptable == null)
{
current = new TemporaryTableFragment(context, members);
}
else
{
current = new TemporaryTableFragment(context, temptable.Name, members);
}
GenerateForUpdateRegister(context, content, current);
var metadata = unit.Table;
var update = new UpdateFragment(context, metadata, name);
update.AddSource(update.Target, current);
GenerateForUpdateMembers(context, unit, update, current);
update.Target.Join(current, metadata.Keys.Concat(metadata.Concurrencys));
block.Add(update);
if (unit == data.MainUnit)
{
mainUpdate = update;
}
if (temptable == null)
{
temptable = current;
}
else
{
current.Members.ForEach(m => temptable.GetMember(m.Property));
}
}
block.Insert(0, GenerateCreateTemplateTable(context, temptable, data.CommitObject, data.Items));
if (data.ReturnMembers.Any())
{
var target = data.SubUnits == null ? mainUpdate.Target : new InheritFragment(context, data.Table);
var select = new SelectFragment(context, target);
select.Members.AddRange(data.ReturnMembers.Select(a => target.GetMember(a.Metadata)));
var datatable = temptable.Clone();
select.AddSource(datatable);
target.Join(datatable, data.Table.Keys);
block.Add(select);
data.GenerateOutput();
}
data.SetConcurrencyExpectCount(data.TableCount + 1);
return(block);
}
//生成复合集合成员虚拟数据源连接。
private ISourceFragment GenerateVirtualCompositeJoinForCollectionMember(GenerateContext context, DbCollectionMemberExpression content, SelectFragment body, bool iscomposite)
{
var relation = CreateSource(context, content.RelationSet);
body.AddSource(relation);
relation.Join = EJoinType.InnerJoin;
var pairs = iscomposite ? content.CompositePairs : content.Pairs;
relation.Condition = pairs.Select(a => body.CreateExpression(a)).Merge();
return(relation);
}
/// <summary>
/// 创建通过临时表关联的返回数据语句片段。
/// </summary>
/// <param name="unit">内容对象。</param>
/// <param name="target">目标对象。</param>
/// <param name="temptable">临时表。</param>
/// <returns>语句片段。</returns>
internal static SelectFragment SelectReturns(this IContentUnit unit, ISourceFragment target, TemporaryTableFragment temptable)
{
var data = (ContentBase)unit;
var context = data.GenerateContext;
var select = new SelectFragment(context, target);
select.Members.AddRange(unit.ReturnMembers.Select(a => target.GetMember(a.Metadata)));
select.AddSource(temptable);
target.Join(temptable, data.Table.Keys);
return(select);
}
