Re: Join question

On Thu, 2007-11-29 at 15:47 -0500, Wolf wrote: > ---- tedd <tedd@sperling.com> wrote: > > Hi gang: > > > > I'm trying to understand joins, > > > > Here's the situation. I have two tables (user1, user2) in one database: > > > > The common field between the two tables is "username". I want to take > > fields "login" and "password" from user2 and populate the same fields > > in user1. > > > > Currently, the table user1 has 5303 entries, whereas user2 has 5909. > > > > What I want at the end of this is for table user1 to have the same > > number of entries as table user2. > > > > Now, how do I set up the query? > > > > TIA for any suggestions. > > > > Cheers, > > > > tedd > > > > PS: Side note -- will safe_mode ON cause problems with this? > > > You should be only "joined" on entries with the same amounts, so if username george > is in both, it should join. > > However if username george_by_george only exists in table 2, then you don't get a join > happening. > > What you would instead want to do is run a loop through the second table and grep the username > against the first table. If it exists, give them command to write table2.pass into table1.pass > If it doesn't exist you want to write table2.user and table2.pass into table1 Grep? Loop? A single query will suffice. Also, he doesn't mention wanting to clobber the passwords in table1 when the username does already exist. Cheers, Rob. -- ........................................................... SwarmBuy.com - http://www.swarmbuy.com Leveraging the buying power of the masses! ...........................................................