Which of the following 3 options is the fastest_PHP Tutorial

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No.0 plate dedecms
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Which of the following three options is the fastest?
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mysql table
a, b, c, d, e, f fields

a is the primary key, type is vachar(20)

Now we need to update, there are 10,000 records in total
To execute the following statement 10,000 times without using transactions

Option 1:
UPDATE table SET b = 222, c = 333, d = 444 WHERE a = xx

Option 2:
REPLACE INTO table VALUES($a,$b,$c,$d,$e,$f)

Option 3:
Waiting for you to write

Let me answer




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1.

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I also want to know about this issue, please help me.

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Option 3! ~[img]http://www.phpchina.com/bbs/images/smilies/default/victory.gif[/img]

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There should be no difference, right?

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The author seems to be working on data synchronization.
There are three requirements for data synchronization: addition, deletion, and modification.
Option 1 only meets the needs for modification.
Option 2 meets the needs for additions and modifications.

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It may be more efficient to encapsulate it into a REPLACE INTO statement, because you only need to send an instruction to the database server once, like this:

REPLACE INTO table VALUES (1, 1, 1, 1),(2, 1, 1, 1),(3, 1, 1, 1),(4, 1, 1, 1);

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[url=http://bbs.phpchina.com/redirect.php?goto=findpost&pid=1067540&ptid=126860]Link tag 6#[/url] faallan

Yes!

But I only need to change it, not add anything.

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[url=http://bbs.phpchina.com/redirect.php?goto=findpost&pid=1067568&ptid=126860]Link tag 7#[/url] Road Trip Baby

replace into is actually a secondary query, first delete and then add
But the advantage is that you can merge several sentences at a time when you are not using the transaction
Since we delete first and then add, I don’t know what will happen under high concurrency. We need to take care of reading
I haven’t actually tested it yet, so I don’t know how much faster it can be