Rockin' the SQL

[brcmapgirl]

I had a great day at work today. In fact, this week has been pretty great at work.

Comments

[silverize]

Ah... sweet, sweet geekery.

I don't tend to use WHERE EXISTS but I should try it. I tend to do subqueries like WHERE xyz in (select xyz from...)

[brcmapgirl]

It is a subquery, but it's important to pull back only one result for each record. That's the key.

[ipsin]

You're doing an "UPDATE ... WHERE EXISTS"... Is it possible that using MERGE would be better?

[brcmapgirl]

MERGE would work if I am doing an UPDATE/INSERT aka UPSERT-ing. But it's only an update and no new insert should be created. For every record pulled from table B, there is an entry on A, because A helps to generate B.

Therefore when I am done, the changed record count should be the total number of records on B.