[vox-tech] MySQL 3.x - deleting orphan rows & datetime()

[Foo Lim]

On Fri, 7 May 2004, David Siedband wrote:

> Greetings,
> 
> I have two questions - using MySQL 3.x
> 
> [1] I'm trying to craft an SQL query to delete orphan rows in index 
> tables
> 
> something like:
> 
> delete from DocWords left join Docs on Docs.ID = DocWords.DocID where 
> Doc.ID is null
> 
> Any suggestions how to do this?

Hi David,

Try using a subquery:

delete from DocWords
where DocID not in
(select ID from Docs);

> [2] Is it possible to emulate the functionality of difftime() in MySQL 
> 3.x without using a scripting language?

I will defer this to someone who knows more than I do...

> thanks!
> --
> David

HTH,
Foo