Protection against the lamer.

How the lamer has removed{has taken off} your protection? Generally, there are many ways. As this clause{article} does not set as the purpose the description of methods of breaking of bases access I shall state the elementary and the most known.

All three methods of the protection which has been mentioned above, have in the basis protection from shift-?. If her{it} to remove{take off}, access to base is free. The elementary method of removal of protection from shift-?, not demanding programming, is import of base. That is the lamer creates empty base and standard operation access imports to it{her} your base. At import all properties of base correspond not. In particular, property allowbypasskey, managing protection from shift-? does not correspond. The received base is protected by nothing.

As during import any your programs do not work to be protected from him{it} it is possible only means itself access. They are available. This creation of own file of working groups, creation of groups of users, purpose{appointment} of access rights by him{it}, parolirovannyj an input{entrance} for each user, etc.

All this is repeatedly described in books on access and to state their maintenance{contents} it is not meaningful.

It is possible to recommend only Jury Prusa's good program "admtools"

(http://am.rusimport.ru/msaccess/pgaccdownload.htm), simplifying job on adjustment and conducting the built - in system of protection access.

In methods of protection against the user it was spoken nothing about protection of base with tables in case you have separated programs (a client part) from actually data. It is considered, that the user simply will not guess to call access and to open base with the data. And if will guess, will be... Oh, as it will be bad...

For protection of base with the data it is unique, that it is possible to make is to apply the built - in protection access.

If you decide to combine protection against the lamer with watching{keeping up} system (namely so I and do{make}) it is necessary to think over well a level of the rights (sanctions) which you give the user.

Do not overlook, that at the moment of the analysis of a mistake the computer will have you, but with the right of the user.

The remark for more skilled. It is possible to make programmku which dynamically changes rights of the user for the manager at all objects of base at use of a confidential input{entrance}. That is for you. Then it is not necessary to think strongly above purpose{appointment} of the rights. And, certainly, to not forget about the program, restoring initial purposes{appointments} of the rights if they have been changed.

Call of this program I place the block of the starting adjustments caused makro autoexec. Programs of change of the rights are rather simple, but individual. Therefore are not resulted. For their spelling help it is sufficient.

End. Protection from skilled akcessista.

As has said at a forum ssy: " the Worthless situation... Protection as though is, but breaks from a half-kick. A problem that the name and a code of the owner of a DB can be defined{determined} with pom. spec. Programs, for example http: // msa.polarcom.ru / "

I can add still the link on zabugornyj a source: http://www.lostpassword.com/access.htm.

The current situation is those. Whether such she should be? The answer, certainly, no. Is the well-known methods, transforming problem{task} of breaking of the password in a np-difficult problem{task}. That is, time of the decision of such problem{task} grows faster any polynom from length of the password (for example, ehkspotencial`no). Algorithms and open programs of such encryption, for example rsa. (to learn{find out} about this algorithm In more detail is possible to the address are known: http://www.leadersoft.ru/subscribe/sub/sub32.htm). Simply for an example if you decide to pick up the password a method full perebora, if in the password latin letters and figures will be applied only, a rating of time of selection = c*62^n, where c - a constant, and n - length of the password. It only cine heroes break the passwords, three times having pressed on enter. Why microsoft does not apply more powerful algorithms of encryption? Something does not come to to me mind any reasonable explanations. And letters to a Gates to write it is useless - he for certain knows about these algorithms... On this pessimistic note it is necessary to finish clause{article}.

ps. The most powerful protection of base is its{her} translation in a format mde. But it is a subject already other clause{article}.

Searches to a database (select command)

I do not set as the purpose to go deep into studying language sql, about it you can read in any management{manual} on sql server, mysql basically supports all basic commands of the standard ansi 92, but select command deserves to devote to her the separate chapter{head}. Select command is used for searches to a database with the purpose of extraction from it{her} the information. Syntax of the command the following:

select [straight_join] [distinct | all] select_expression...

[from tables... [where where_definition] [group by column...]

[order by column [asc | desc]...] having full_where_definition

[limit [offset,] rows] [procedure procedure_name]]

[into outfile ' file_name '...]

Apparently from above-stated, together with select command keywords which use very much influences the answer of the server are used. We shall consider each of them.

distinct..

Passes{Misses} lines in which all chosen fields are identical, that is eliminates duplication of the data.

where.

The offer of select command which allows to establish predicates which condition can be correct or incorrect for any line of the table. Those lines for which such statement is correct are taken only. For example:

select u_id, lname from publishers where city = ' new york ';

Deduces columns u_id and lname from the table publishers for which value in stolbce city-new york. It enables to query more concrete.