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Re: MYSQL
Posted: Thu Dec 13, 2012 7:29 am
by t57042
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
Re: MYSQL
Posted: Thu Dec 13, 2012 8:49 am
by mol
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
Re: MYSQL
Posted: Thu Dec 13, 2012 9:29 am
by Rathinagiri
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?
Re: MYSQL
Posted: Thu Dec 13, 2012 10:55 am
by mol
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