/// <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);
}
internal static UpdateFragment UpdateByTemptable(this ContentBase data, CommitUnitBase unit, SourceFragment current, DbName name = null)
{
var context = data.GenerateContext;
var metadata = unit.Table;
var update = new UpdateFragment(context, metadata, name);
update.AddSource(update.Target, current);
data.SetCommitMembers(update, unit, current);
update.Target.Join(current, data.UnionConcurrencyMembers(metadata, metadata.Keys));
return(update);
}
internal static UpdateFragment UpdateByKeys(this ContentBase data, CommitUnitBase unit, DbName name = null)
{
var context = data.GenerateContext;
var metadata = unit.Table;
var update = new UpdateFragment(context, metadata, name);
data.CommitObject.Parent = update;
data.SetCommitMembers(update, unit);
update.Where = update.Target.JoinCondition(data.CommitObject, data.UnionConcurrencyMembers(metadata, metadata.Keys));
return(update);
}
/// <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);
}