Enormous Bug In 5.18, Fixed In 5.19?

[peterlaursen]

One thread per question only please!

Does this answer you question?

http://webyog.com/faq/28_70_en.html

EVERY database client does so, with identical rows!

If not then explain your self more in detail.

[peterlaursen]

Now ..

It seems that I have a mail from a developer. There is an issue. I do not usnderstand details. It is fixed in the 5.2 beta 4 tree, I was told

[peterlaursen]

What we can reproduce with this schema is that if more rows have the same value for the numerical field and you change that numerical field (not a text filed) SQLyog sends SQL like

Code:

update `tbl_requetes` set `Req_ID`='abc',`Req_Sql`='def', `Req_Param`='ghi' ,`Req_Description`='jkl' ,`Req_Type`='2' ,`Req_Libelle`='mno' where `Req_Type`='1';

what results in all rows having `Req_Type`='1' to become updated even if the text fileds are not identical.

The where-clause:

Code:

where `Req_Type`='1';

would be OK if that field was a PK. But it is not and it is a bug.

[peterlaursen]

… but you really SHOULD have a primary key in the table because without a PK the WHERE-condition must include all columns. With such WHERE MySQL cannot use indexes at all and with some data in the database an update can be very slow.

BTW: do you have any particular reason to use TEXTs for all fields and not VARCHARS ?

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