Re: back-sql

["Pierangelo Masarati" <masarati@aero.polimi.it>]

Uwe Hering writes: 

> Hi, 
>
> I'm just trying to use openldap in connection with mysql, that is
> using back-sql. 
>
> Version are: 
>
> openldap-2.1.4
> MyODBC-2.50.39
> unixODBC-2.1.1 
>
> Checking the examples unter ..../rdbms_depend/mysql there where
> three problems, one is left. 
>
> First problem was a missing attribute "documentDN" within the schema
> definition which has been used within the mysql tables. Just
> deleting the line within the database was okay since it is obviously 
> not used. 
>
> Second problem was that in addition to the manpage a column called
> "sel_expr_u" is used within the standard "at_query". Adding this
> column to the table helped (stating the "at_query" without this
> column within slapd.conf should also work).  
>
> Third problem is: if I do any search within the ldap I get nothing
> back. Since slapd -d 5 did not show up any errors or problems, 
> examining the mysql-logfile revealed an interesting detail: 
>
> any sql-query showed similar: 
>
> SELECT DISTINCT ldap_entries.id,persons.id,'inetOrgPerson' AS
> objectClass,ldap_entries.dn AS dn FROM ldap_entries,persons WHERE
> persons.id=ldap_entries.keyval AND ldap_entries.oc_map_id=1 AND
> ldap_entries.dn LIKE CONCAT('%','UR=C,LQS=O%') AND NOT
> ('inetOrgPerson' IS NULL) 
>
>
> I assume that the string "LIKE CONCAT('%','UR=C,LQS=O%')" ist not
> correct. Changing it to "LIKE CONCAT('%','O=SQL,C=RU%')" works
> within mysql properly. 
>
>
> Does anybody know wether this might be a configuration problem or
> could it be a source problem (openldap | unixODBC | MySQLODBC)?

Late versions of back-sql before it was ported to 2.1 contained
some auto-detection of exoteric features of specific RDBMSes,
inclusing this reverse uppercased (ru) dnstore and  lookup
(as you see, the DN you're searching for is written from right
to left ...).  Unfortunately this is not consistently used
throughout the code, or there's something that I'm missing.
To avoid the problem, you should explicitly tell back-sql
you don't want to use such feature by adding 

has_ldapinfo_dn_ru      no 

to slapd.conf (as stated in slapd-sql(5) in current HEAD,
dunno if it is already there in 2.1.4 man page but surely is
in 2.1.4 code). 

This directive is subjected to change, and it is mainly meant
as a temporary workaround for failures in auto-detecting the
sql side arrangement. 

Pierangelo. 

Dr. Pierangelo Masarati               | voice: +39 02 2399 8309
Dip. Ing. Aerospaziale                | fax:   +39 02 2399 8334
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