MYSQL

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t57042
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Re: MYSQL

Post by t57042 » Thu Dec 13, 2012 7:29 am

When using XBASE (in multiuser using NAS) , record and filelocking functions are provided in the language(Rlock .....).

How do you handle concurrency with MySQL?

Richard

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mol
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Post by mol » Thu Dec 13, 2012 8:49 am

I've tried to realise record locking with MySql.
I've got strange results.
One one machine record locking worked OK, on another machine there was no record locking.
I've written to Harbour providers, but without any constructive results.
It depended on MySql version installed on computer (I've tried to install the same version, but with the same results).

For record locking you must use phrase:

Code: Select all

select * from any_table where record_ID=your_ID for UPDATE
here is a little sample:
http://www.molsystemy.pl/hmg/mysql_reco ... g_demo.zip

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Rathinagiri
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Post by Rathinagiri » Thu Dec 13, 2012 9:29 am

IMHO locking is carried on automatically without our interference.

If we use begin transaction and end transaction sequence, ACID requirements are satisfied.

Marek,

In what way == is different from = in this situation?
East or West HMG is the Best.
South or North HMG is worth.
...the possibilities are endless.

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Post by mol » Thu Dec 13, 2012 10:55 am

rathinagiri wrote:IMHO locking is carried on automatically without our interference.

If we use begin transaction and end transaction sequence, ACID requirements are satisfied.

Marek,

In what way == is different from = in this situation?
because of text comparison method
= (equality) operator
== exactly equal

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