/// <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);
}
internal static InsertValueFragment InsertTemptable(this ContentBase data, TemporaryTableFragment temptable, IEnumerable <CommitMember> members)
{
var context = data.GenerateContext;
var insert = new InsertValueFragment(context, temptable, data.CommitObject, data.Items);
data.CommitObject.Parent = insert;
members.ForEach(member => SetCommitMember(insert, member));
return(insert);
}
/// <summary>
/// 创建通过临时博删除的语句片段。
/// </summary>
/// <param name="data">内容对象。</param>
/// <param name="metadata">删除表的元数据。</param>
/// <param name="temptable">临时表。</param>
/// <param name="name">指定名称。</param>
/// <returns>语句片段。</returns>
internal static DeleteFragment DeleteByTemptable(this ContentBase data
, TableMetadata metadata, TemporaryTableFragment temptable, DbName name = null)
{
var context = data.GenerateContext;
var filterMembers = data.UnionConcurrencyMembers(metadata, metadata.Keys);
var delete = new DeleteFragment(context, metadata);
var current = delete.Target;
var currenttemptable = new TemporaryTableFragment(context, filterMembers, temptable.Name);
delete.AddSource(currenttemptable);
current.Join(currenttemptable, filterMembers);
return(delete);
}
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);
}
/// <summary>
/// 表达式生成删除语句。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="content">生成表达式。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForDeleteStatement(GenerateContext context, DbExpression content)
{
var data = (StatementContent)context.Data;
var item = data.ItemEpxression;
var source = CreateSource(context, content) as QueryBaseFragment;
var table = data.Table;
if (table.InheritSets.Length == 0)
{
var target = (TableFragment)GetSource(context, item);
target.Name = context.ConvertName(data.TargetName);
var delete = new DeleteFragment(context, target)
{
Where = source.Where,
Take = source.Take
};
delete.AddSource(source.Sources.Where(a => a != target));
return(delete);
}
else
{
var createtable = new CreateTempTableFragment(context, table.Keys);
var insert = new InsertFragment(context, createtable.Table, source);
insert.Members.AddRange(createtable.Table.Members);
foreach (var key in table.Keys)
{
RetrievalMember(context, source, new DbMemberExpression(key.Member, item), null, false);
}
var block = new BlockFragment(context, createtable, insert);
foreach (var subtable in table.InheritSets.Concat(new TableMetadata[] { table }).Reverse())
{
var current = new TableFragment(context, subtable);
var delete = new DeleteFragment(context, current);
var temptable = new TemporaryTableFragment(context, table.Keys, createtable.Table.Name);
current.Join(temptable, table.Keys);
delete.AddSource(temptable);
block.Add(delete);
}
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);
}
/// <summary>
/// 生成用于插入的语句片段。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="content">插入表达式。</param>
/// <returns>生成结果。</returns>
protected virtual SqlFragment GenerateForInsertStatement(GenerateContext context, DbExpression content)
{
var data = (StatementContent)context.Data;
var newitem = (DbNewExpression)data.ItemEpxression;
var source = CreateSource(context, content) as QueryBaseFragment;
var metadata = data.Table;
if (metadata.InheritSets.Length == 0)
{
var target = new TableFragment(context, metadata, data.TargetName);
var insert = new InsertFragment(context, target, source);
GenerateForInsertStatementMembers(context, newitem, source, insert, member => metadata.Members[member]);
return(insert);
}
else
{
var allsource = metadata.InheritSets.Concat(new TableMetadata[] { metadata });
var allmembers = allsource.SelectMany(a => a.Members).ToDictionary(a => a.Member, a => a);
var createtable = new CreateTempTableFragment(context, newitem.Members.Keys.OfType <PropertyInfo>().Select(a => allmembers[a]));
var insert = new InsertFragment(context, createtable.Table, source);
GenerateForInsertStatementMembers(context, newitem, source, insert, member => allmembers[member]);
var block = new BlockFragment(context, createtable, insert);
var query = from a in newitem.Members.Keys.OfType <PropertyInfo>().Select(m => allmembers[m])
group a by a.Table into g
select new { g.Key, Members = g };
var prefixMembers = query.First().Members.Where(a => a.IsKey);
foreach (var g in query)
{
IEnumerable <ColumnMetadata> currentMembers = g.Members;
if (g.Key.InheritSets.Length > 0)
{
currentMembers = prefixMembers.Concat(g.Members);
}
var current = new TemporaryTableFragment(context, currentMembers, createtable.Table.Name);
block.Add(context.Insert(current, g.Key, currentMembers));
}
return(block);
}
}
/// <summary>
/// 使用临时表形式，生成删除若干数据对象（多个主键）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>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForDeleteKeysTempTable(GenerateContext context)
{
var data = (GenerateDataForDelete)context.Data;
var block = new BlockFragment(context)
{
GenerateCreateTemplateTable(context, data.CommitObject, data.Items, data.Table.Keys.Concat(data.ConcurrencyMembers))
};
var temptable = ((CreateTempTableFragment)block.First()).Table;
var name = data.TargetName;
foreach (var metadata in data.GetTables())
{
var delete = new DeleteFragment(context, metadata, name);
var current = delete.Target;
var currenttemptable = new TemporaryTableFragment(context, temptable.Name, metadata.Keys.Union(metadata.Concurrencys));
delete.AddSource(currenttemptable);
current.Join(currenttemptable, metadata.Keys.Union(metadata.Concurrencys));
block.Add(delete);
}
data.SetConcurrencyExpectCount(data.TableCount + 1);
return(block);
}
/// <summary>
/// 初始化创建临时表。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <param name="table">仔在临时表。</param>
public CreateTempTableFragment(GenerateContext context, TemporaryTableFragment table)
: base(context)
{
Table = table;
IsVariable = context.Feature.HasCapable(EDbCapable.TableVariable);
}
/// <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);
}
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);
}
}
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);
}
