我有一个表，其中有一堆不同的服务器，大多数都被列为 servername.ad.edu。我想删除第一个点之后的所有内容。所以它在我的表中只显示为 servername。提供给我的用于填充表的代码不是我写的，但我确实添加了 LEFT 语句，看看我是否可以在填充过程中删除它。以下是我的代码...

DELETE FROM clean_tanium_server;
MERGE clean_tanium_server AS Target
USING tanium_server AS Source
ON Source.computer_id = Target.computer_id AND Source.[ci_installed_application name] = Target.application_name
WHEN NOT MATCHED BY Target THEN
    INSERT (computer_id, computer_name, operating_system, application_name, application_normalized_name, chassis_type, cpu_core, cpu_processor, ip_address)
    VALUES (Source.computer_id, Source.computer_name, Source.operating_system, Source.[ci_installed_application name], Source.[ci_installed_application normalized_name], Source.chassis_type, Source.cpu_core, Source.cpu_processor, Source.ip_address)
WHEN MATCHED THEN UPDATE SET
    *Target.computer_name = LEFT(Source.computer_name, CHARINDEX('.', Source.computer_name) - 1),*
    Target.operating_system = Source.operating_system,
    Target.application_normalized_name = Source.[ci_installed_application normalized_name]
WHEN NOT MATCHED BY Source THEN
    DELETE;

所以我不明白为什么当我填充表的时候，他们没有省略.ad.edu部分。任何帮助都是非常感谢的。谢谢。
当前外观：

computer_name
servername1.ad.edu
servername2.ad.edu
servername3.us.edu

我希望它看起来如何：

computer_name
servername1
servername2
servername3