/// <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);
}
private SqlFragment GenerateForInsertIdentityMultipleRepeat(GenerateContext context, CommitIdentityUnit mainunit, ColumnMetadata rowindex,
TemporaryTableFragment temporaryTable, RowIndexFragment rowindexfragment, GenerateDataForInsert data, out TableFragment whileTarget)
{
var repeatfragment = new RepeatBlockFragment(context, data.Items);
var block = repeatfragment.Block;
var whileInsert = context.Insert(temporaryTable, mainunit.Table,
mainunit.Members.Where(a => a.ValueType != ECommitValueType.Database).Select(a => a.Metadata));
var whileSelect = (QueryBaseFragment)whileInsert.Query;
whileSelect.Where = context.Equal(temporaryTable.GetMember(rowindex), new RowIndexFragment(context));
block.Add(whileInsert);
var whileUpdate = new UpdateFragment(context, temporaryTable);
var getidentity = whileUpdate.CreateExpression(
context.Translate(Expression.Call(null, SupportMembers.DbFunctions.GetIdentity)));
whileUpdate.SetValue(mainunit.Identity.Metadata, getidentity);
whileUpdate.Where = context.Equal(temporaryTable.GetMember(rowindex), new RowIndexFragment(context));
block.Add(whileUpdate);
whileTarget = (TableFragment)whileInsert.Target;
return(repeatfragment);
}
private WhileFragment GenerateForInsertIdentityMultipleWhile(GenerateContext context, CommitIdentityUnit mainunit, CreateVariableFragment index,
ColumnMetadata rowindex, TemporaryTableFragment temporaryTable, RowIndexFragment rowindexfragment, out TableFragment whileTarget)
{
var whilefragment = new WhileFragment(context, context.LessThan(index.Name, rowindexfragment));
var block = whilefragment.Block;
var whileInsert = context.Insert(temporaryTable, mainunit.Table,
mainunit.Members.Where(a => a.ValueType != ECommitValueType.Database).Select(a => a.Metadata));
var whileSelect = (QueryBaseFragment)whileInsert.Query;
whileSelect.Where = context.Equal(temporaryTable.GetMember(rowindex), index.Name);
block.Add(whileInsert);
var whileUpdate = new UpdateFragment(context, temporaryTable);
var getidentity = whileUpdate.CreateExpression(
context.Translate(Expression.Call(null, SupportMembers.DbFunctions.GetIdentity)));
whileUpdate.SetValue(mainunit.Identity.Metadata, getidentity);
whileUpdate.Where = context.Equal(temporaryTable.GetMember(rowindex), index.Name);
block.Add(whileUpdate);
block.Add(context.Assign(index.Name, context.Add(index.Name, context.StatementString("1"))));
whileTarget = (TableFragment)whileInsert.Target;
return(whilefragment);
}
internal static InsertFragment InsertTemptable(this ContentBase data, TemporaryTableFragment temptable, CommitKeyUnit unit, DbName name = null)
{
var members = unit.Keys.Concat(unit.Members).Select(a => a.Metadata);
var context = data.GenerateContext;
var table = new TableFragment(context, unit.Table, name);
var select = new SelectFragment(context, temptable);
var current = new InsertFragment(context, table, select);
foreach (var member in members)
{
select.CreateMember(null, temptable.GetMember(member));
current.CreateMember(null, member);
}
return(current);
}