fenway

PHPMyAdmin has an export (which really just mysqldump).

Sure... SELECT test1.* FROM test1 INNER JOIN test2 ON (test1.column1 = test2.column3)

The syntax with VALUES() is my preference -- just make sure you list the columns, too.

These is classic "cross-tab" or "pivot-table"...

I'm not sure what you mean... Are you sure the queries executing without error? Where any rows affected?

Performance-wise, it's a substantial improvement if you're inserting many rows.

That's not really specific... I mean a specific question about how to query.

"One particular forum" isn't enough information... at the very least, post the table structure, and we can hazard a guess.

You can't have a single table be two things.

Original post was TLDR; could you summarize?

Nope.

Why are there no indexes on the usr table? Like on usrID?

You can used many VALUES() one after the other to insert N multiple rows... assuming you don't need the IDs of the newly created rows back, it's much faster than running N insert statements.

Having 2 tables with the same data. The MyISAM table does the reading while the InnoDB does the writing? Assuming you're talking about completely unrelated tables, sure... if they're related, you're going to run into all sorts of issues.

There's no difference in this case, the optimizer will figure that out right away... so you're not really testing anything. The difference will come about when there are NULL values in the join-ed field during the LEFT JOIN.

MySQL doesn't know about php variables. Which query are we talking about? Does one not work? You're absorbing errors.

Duplicate word.

You can EXTRACT the YEARMONTH.

Auto-skipping? What does that mean?

Experience doing what?

I understand what you're looking for... but JOINs don't work well with ranges.

Well, if you know how many are in between, then you can multiply by the gap (plus an extra 50% fudge factor), and then "mark" the middle row, and work backwards.

Yes, but that can blow up index usage... see what happens if you move the expressions to where where clause.

Well, that's 20% failure! You need to log, at the very least, the queries going to the DB (which mysql can do for you), as well as some debugging info on the php side.

That's a comma... you were using ticks. Use quotes (').