/// <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>
/// 生成更新若干关系对象（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 GenerateForRelationDeleteKey(GenerateContext context)
{
var data = (RelationContent)context.Data;
var metadata = data.Items.Navigate;
var update = new UpdateFragment(context, data.Table);
update.AddSource(update.Target);
metadata.Pairs.ForEach(
pair => update.SetValue(pair.ForeignKey, new SimpleFragment(context, "NULL")));
var member = new CommitMemberFragment(context, data.Loader, update, data.Table.Keys[0].Member);
var values = new ValueListFragment(context, member, data.Items);
var keyMember = update.Target.GetMember(data.Table.Keys[0]);
update.Where = new ScalarFragment(context, values, keyMember)
{
Function = SupportMembers.Enumerable.Contains
};
return(update);
}
/// <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);
}
