Also, surely if you left join to a table then if there's no matching row you get a null value in your result set. So I'm not sure what the difference is between getting that null because you store it in a column in the primary table, and deriving it by left joining to a related table with no matching rows. James Harvard
At 11:27 am +0000 16/3/06, [EMAIL PROTECTED] wrote: >As someone totally unread in the theory of databases, that seems unduly >puritanical. I assume that what Date would propose is that you have another >table (related by master key) in which, if you do not know something, you do >not enter it. But this means that if you have 10 different pieces of >potentially but not necessarily available information about a single master >record (e.g. a person), you have to do a 10-way join in order to retrieve all >the information about them. Replacing a theoretically ugly null flag with a 10 >way join strikes me, as an engineer rather than a theoretician, the wrong side >of the elegance/practicality trade-off. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
