/// <summary>
/// 创建通过主键删除的语句片段。
/// </summary>
/// <param name="data">内容对象。</param>
/// <param name="table">删除表的元数据。</param>
/// <param name="name">指定名称。</param>
/// <returns>语句片段。</returns>
internal static DeleteFragment DeleteByKeys(this ContentBase data, TableMetadata table, DbName name = null)
{
var delete = new DeleteFragment(data.GenerateContext, table, name);
delete.Where = delete.Target.JoinCondition(data.CommitObject,
data.UnionConcurrencyMembers(table, table.Keys));
return(delete);
}
/// <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);
}
/// <summary>
/// 创建通过 IN 主键删除的语句片段。
/// </summary>
/// <param name="data">内容对象。</param>
/// <param name="table">删除表的元数据。</param>
/// <param name="key">主键元数据。</param>
/// <param name="values">值列表对象。</param>
/// <param name="name">指定名称。</param>
/// <returns>语句片段。</returns>
internal static DeleteFragment DeleteInKey(this ContentBase data, TableMetadata table
, ColumnMetadata key, ValueListFragment values, DbName name = null)
{
var context = data.GenerateContext;
var delete = new DeleteFragment(context, table, data.TargetName);
var keyMember = delete.Target.GetMember(key);
delete.Where = new ScalarFragment(context, values, keyMember)
{
Function = SupportMembers.Enumerable.Contains
};
return(delete);
}
/// <summary>
/// 生成删除单个数据对象语句
/// </summary>
/// <param name="context">生成上下文</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForDeleteSingle(GenerateContext context)
{
var data = (GenerateDataForDelete)context.Data;
var block = new BlockFragment(context);
var name = data.TargetName;
foreach (var table in data.GetTables())
{
var delete = new DeleteFragment(context, table, name);
delete.Where = delete.Target.JoinCondition(data.CommitObject, table.Keys.Union(table.Concurrencys));
block.Add(delete);
}
data.SetConcurrencyExpectCount(data.TableCount);
return(block);
}
/// <summary>
/// 生成删除单个复合关系对象语句。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForRelationDelete(GenerateContext context)
{
var data = (RelationContent)context.Data;
var metadata = (CompositeNavigateMetadata)data.Items.Navigate;
var target = new TableFragment(context, data.Table);
var source = data.CommitObject;
var delete = new DeleteFragment(context, target);
delete.Where = metadata.Pairs.Concat(metadata.CompositePairs).Select(
pair => new BinaryFragment(context, Expressions.EBinaryKind.Equal)
{
Left = target.GetMember(pair.ForeignKey),
Right = source.GetMember(pair.PrincipalKey)
}).Merge();
return(delete);
}
/// <inheritdoc/>
protected override SqlFragment GenerateForDeleteContent(GenerateContext context, DbExpression content)
{
var data = (DeleteContent)context.Data;
data.SetConcurrencyExpectCount(1);
var metadata = data.Table;
if (data.Items.Count > 1 && metadata.Keys.Length > 1)
{
var values = new ValuesFragment(context, data.CommitObject, data.Items, data.Table);
var filterMembers = data.UnionConcurrencyMembers(metadata, metadata.Keys);
var delete = new DeleteFragment(context, metadata);
var current = delete.Target;
delete.AddSource(values);
current.Join(values, filterMembers);
return(delete);
}
return(base.GenerateForDeleteContent(context, content));
}
/// <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));
}
/// <inheritdoc/>
protected override SqlFragment GenerateForRelation(GenerateContext context, DbExpression content)
{
var data = (RelationContent)context.Data;
if (data.Items.Count > 1)
{
var metadata = data.Items.Navigate;
if (data.IsAddRelation && !metadata.IsComposite)
{
var columns = data.Source.Keys.Concat(metadata.Pairs.Select(a => a.ForeignKey));
var values = new ValuesFragment(context, data.CommitObject, data.Items);
data.Source.Keys.ForEach(key => values.SetValue(key));
if (data.IsAddRelation)
{
metadata.Pairs.ForEach(
pair => values.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
}
var update = new UpdateFragment(context, data.Table);
update.AddSource(update.Target, values);
foreach (var pair in metadata.Pairs)
{
update.SetValue(pair.ForeignKey, values.GetMember(pair.ForeignKey));
}
update.Target.Join(values, data.Table.Keys);
return(update);
}
else if (!data.IsAddRelation && metadata.IsComposite)
{
var composite = (CompositeNavigateMetadata)data.Items.Navigate;
var values = new ValuesFragment(context, data.CommitObject, data.Items);
composite.Pairs.ForEach(pair => values.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
composite.CompositePairs.ForEach(pair => values.SetValue(pair.ForeignKey, data.CommitObject.GetMember(pair.PrincipalKey)));
var target = new TableFragment(context, data.Table);
var delete = new DeleteFragment(context, target);
delete.AddSource(values);
target.Join(values, composite.Pairs.Select(a => a.ForeignKey).Concat(composite.CompositePairs.Select(a => a.ForeignKey)));
return(delete);
}
}
return(base.GenerateForRelation(context, content));
}
/// <summary>
/// 生成删除若干数据对象（单个主键）语句。
/// </summary>
/// <param name="context">生成上下文。</param>
/// <returns>语句片段。</returns>
protected virtual SqlFragment GenerateForDeleteKey(GenerateContext context)
{
var data = (GenerateDataForDelete)context.Data;
var block = new BlockFragment(context);
var key = data.Table.Keys[0];
var member = (CommitMemberFragment)data.CommitObject.GetMember(key);
var values = new ValueListFragment(context, member, data.Items);
var name = data.TargetName;
foreach (var table in data.GetTables())
{
var delete = new DeleteFragment(context, table, name);
var keyMember = delete.Target.GetMember(key);
delete.Where = new ScalarFragment(context, values, keyMember)
{
Function = SupportMembers.Enumerable.Contains
};
block.Add(delete);
}
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);
}
