/// <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 GenerateForInsertTempTable(GenerateContext context)
{
var data = (GenerateDataForInsert)context.Data;
var members = data.GetTables().SelectMany(a => a.Members);
var createtable = new CreateTempTableFragment(context, members);
var temptable = createtable.Table;
var insert = new InsertValueFragment(context, temptable, data.CommitObject, data.Items);
var mainunit = (CommitKeyUnit)data.MainUnit;
mainunit.Keys.ForEach(member => GenerateForInsertMembers(insert, member));
data.CommitObject.Parent = insert;
foreach (var unit in data.GetUnits())
{
unit.Members.ForEach(member => GenerateForInsertMembers(insert, member));
}
var block = new BlockFragment(context, createtable, insert);
InsertFragment mainInsert = null;
foreach (var unit in data.GetUnits().OfType <CommitKeyUnit>())
{
mainInsert = context.Insert(temptable, unit);
block.Add(mainInsert);
}
GenerateForInsertReturnStatement(context, block, mainInsert.Target, temptable);
return(block);
}
/// <summary>
/// 使用临时表形式，生成插入单个数据对象语句，对象的主键是标识列，
/// 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 GenerateForInsertIdentityTempTable(GenerateContext context)
{
var data = (GenerateDataForInsert)context.Data;
var mainunit = (CommitIdentityUnit)data.MainUnit;
var members = data.GetTables().SelectMany(a => a.Members).ToList();
var rowindex = new ColumnMetadata(data.Table, SupportMembers.DbMembers.CustomRowIndex,
members.Select(a => a.Name).Unique("RowIndex"));
members.Add(rowindex);
var createtable = new CreateTempTableFragment(context, members);
var temptable = createtable.Table;
var insert = new InsertValueFragment(context, temptable, data.CommitObject, data.Items);
data.CommitObject.Parent = insert;
foreach (var unit in data.GetUnits())
{
unit.Members.ForEach(member => GenerateForInsertMembers(insert, member));
}
insert.SetValue(mainunit.Identity.Metadata, new SimpleFragment(context, "0"));
var rowindexfragment = new RowIndexFragment(context);
insert.SetValue(rowindex, rowindexfragment);
TableFragment whileTarget = null;
BlockFragment block = null;
if (context.Feature.HasCapable(EDbCapable.ExternalCompoundStatement))
{
var index = new CreateVariableFragment(context, typeof(int));
var whilefragment = GenerateForInsertIdentityMultipleWhile(context, mainunit, index,
rowindex, createtable.Table, rowindexfragment, out whileTarget);
block = new BlockFragment(context, index, createtable, insert,
context.Assign(index.Name, context.StatementString("1")), whilefragment);
}
else
{
var repeatfragment = GenerateForInsertIdentityMultipleRepeat(context, mainunit,
rowindex, createtable.Table, rowindexfragment, data, out whileTarget);
block = new BlockFragment(context, createtable, insert, repeatfragment);
}
if (data.SubUnits != null)
{
foreach (var unit in data.SubUnits)
{
block.Add(context.Insert(createtable.Table, unit));
}
}
GenerateForInsertReturnStatement(context, block, whileTarget, createtable.Table);
return(block);
}
/// <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);
}
}
/// <summary>
/// 使用临时表形式，生成删除多个复合关系的语句，
/// 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 GenerateForRelationDeleteTempTable(GenerateContext context)
{
var data = (RelationContent)context.Data;
var composite = (CompositeNavigateMetadata)data.Items.Navigate;
var createtemptable = new CreateTempTableFragment(context,
composite.Pairs.Select(a => a.ForeignKey).Concat(composite.CompositePairs.Select(a => a.ForeignKey)));
var insert = new InsertValueFragment(context, createtemptable.Table, data.CommitObject, data.Items);
composite.Pairs.ForEach(pair => insert.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
composite.CompositePairs.ForEach(pair => insert.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
var temptable = createtemptable.Table;
var target = new TableFragment(context, data.Table);
var delete = new DeleteFragment(context, target);
delete.AddSource(temptable);
target.Join(temptable, composite.Pairs.Select(a => a.ForeignKey).Concat(composite.CompositePairs.Select(a => a.ForeignKey)));
return(new BlockFragment(context, createtemptable, insert, delete));
}
/// <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，生成更新关系语句，
/// 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 GenerateForRelationUpdateTempTable(GenerateContext context)
{
var data = (RelationContent)context.Data;
var metadata = data.Items.Navigate;
var block = new BlockFragment(context);
var createtemptable = new CreateTempTableFragment(context,
data.IsAddRelation ? data.Source.Keys.Concat(metadata.Pairs.Select(a => a.ForeignKey)) : data.Source.Keys);
var insert = new InsertValueFragment(context, createtemptable.Table, data.CommitObject, data.Items);
data.Source.Keys.ForEach(key => insert.SetValue(key));
if (data.IsAddRelation)
{
metadata.Pairs.ForEach(
pair => insert.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
}
var temptable = createtemptable.Table;
var update = new UpdateFragment(context, data.Table);
update.AddSource(update.Target, temptable);
if (data.IsAddRelation)
{
foreach (var pair in metadata.Pairs)
{
update.SetValue(pair.ForeignKey, temptable.GetMember(pair.ForeignKey));
}
}
else
{
var nullfargment = new SimpleFragment(context, "NULL");
foreach (var pair in metadata.Pairs)
{
update.SetValue(pair.ForeignKey, nullfargment);
}
}
update.Target.Join(temptable, data.Table.Keys);
return(new BlockFragment(context, createtemptable, insert, update));
}
