xbase::base(3pm) [debian man page]
XBase::Base(3pm) User Contributed Perl Documentation XBase::Base(3pm) NAME
XBase::Base - Base input output module for XBase suite SYNOPSIS
Used indirectly, via XBase or XBase::Memo. DESCRIPTION
This module provides catch-all I/O methods for other XBase classes, should be used by people creating additional XBase classes/methods. There is nothing interesting in here for users of the XBase(3) module. Methods in XBase::Base return nothing (undef) on error and the error message can be retrieved using the errstr method. Methods are: new Constructor. Creates the object and if the file name is specified, opens the file. open Opens the file and using method read_header reads the header and sets the object's data structure. The read_header should be defined in the derived class, there is no default. close Closes the file, doesn't destroy the object. drop Unlinks the file. create_file Creates file of given name. Second (optional) parameter is the permission specification for the file. The reading/writing methods assume that the file has got header of length header_len bytes (possibly 0) and then records of length record_len. These two values should be set by the read_header method. seek_to, seek_to_record Seeks to absolute position or to the start of the record. read_record, read_from Reads data from specified position (offset) or from the given record. The second parameter (optional for read_record) is the length to read. It can be negative, and at that case the read will not complain if the file is shorter than requested. write_to, write_record Writes data to the absolute position or to specified record position. The data is not padded to record_len, just written out. General locking methods are locksh, lockex and unlock, they call _locksh, _lockex and _unlock which can be redefined to allow any way for locking (not only the default flock). The user is responsible for calling the lock if he needs it. No more description -- check the source code if you need to know more. VERSION
1.02 AVAILABLE FROM
http://www.adelton.com/perl/DBD-XBase/ AUTHOR
(c) 1997--2011 Jan Pazdziora. SEE ALSO
perl(1), XBase(3) perl v5.12.4 2011-08-31 XBase::Base(3pm)
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DBD::XBase(3pm) User Contributed Perl Documentation DBD::XBase(3pm) NAME
DBD::XBase - DBI driver for XBase compatible database files SYNOPSIS
use DBI; my $dbh = DBI->connect("DBI:XBase:/directory/subdir") or die $DBI::errstr; my $sth = $dbh->prepare("select MSG from test where ID != 1") or die $dbh->errstr(); $sth->execute() or die $sth->errstr(); my @data; while (@data = $sth->fetchrow_array()) { ## further processing } $dbh->do('update table set name = ? where id = 45', {}, 'krtek'); DESCRIPTION
DBI compliant driver for module XBase. Please refer to DBI(3) documentation for how to actually use the module. In the connect call, specify the directory containing the dbf files (and other, memo, etc.) as the third part of the connect string. It defaults to the current directory. Note that with dbf, there is no database server that the driver would talk to. This DBD::XBase calls methods from XBase.pm module to read and write the files on the disk directly, so any limitations and features of XBase.pm apply to DBD::XBase as well. DBD::XBase basically adds SQL, DBI compliant interface to XBase.pm. The DBD::XBase doesn't make use of index files at the moment. If you really need indexed access, check XBase(3) for notes about support for variour index types. SUPPORTED SQL COMMANDS
The SQL commands currently supported by DBD::XBase's prepare are: select select fields_or_expressions from table [ where condition ] [ order by field ] Fields_or_expressions is a comma separated list of fields or arithmetic expressions, or a "*" for all fields from the table. The "where" condition specifies which rows will be returned, you can have arbitrary arithmetic and boolean expression here, compare fields and constants and use "and" and "or". Match using "like" is also supported. Examples: select * from salaries where name = "Smith" select first,last from people where login = "ftp" or uid = 1324 select id,first_name,last_name from employ where last_name like 'Ki%' order by last_name select id + 1, substr(name, 1, 10) from employ where age > 65 select id, name from employ where id = ? You can use bind parameters in the where clause, as the last example shows. The actual value has to be supplied via bind_param or in the call to execute or do, see DBI(3) for details. To check for NULL values in the "where" expression, use "id is null" and "id is not null", not "id == null". Please note that you can only select from one table, joins are not supported and are not planned to be supported. If you need them, get a real RDBMS (or send me a patch). In the arithmetic expressions you can use a couple of SQL functions -- currently supported are concat, substr (and substring), trim, ltrim and rtrim, length. I do not have an exact idea of which and how many functions I want to support. It's easy to write them in a couple of minutes now the interface is there (check the XBase::SQL module if you want to send a patch containing support for more), it's just that I do not really need them and sometimes it's hard to tell what is useful and what is SQL92 compatible. Comment welcome. The select command may contain and order by clause. Only one column is supported for sorting at the moment, patches are welcome. The group by clause is not supported (and I do not plan them), nor are the aggregate functions. delete delete from table [ where condition ] The "where" condition is the same as for select. Examples: delete from jobs ## emties the table delete from jobs where companyid = "ISW" delete from jobs where id < ? insert insert into table [ ( fields ) ] values ( list of values ) Here fields is a (optional) comma separated list of fields to set, list of values is a list of constants to assign. If the fields are not specified, sets the fields in the natural order of the table. You can use bind parameters in the list of values. Examples: insert into accounts (login, uid) values ("guest", 65534) insert into accounts (login, uid) values (?, ?) insert into passwd values ("user","*",4523,100,"Nice user", "/home/user","/bin/bash") update update table set field = new value [ , set more fields ] [ where condition ] Example: update passwd set uid = 65534 where login = "guest" update zvirata set name = "Jezek", age = 4 where id = 17 Again, the value can also be specified as bind parameter. update zvirata set name = ?, age = ? where id = ? create table create table table name ( columns specification ) Columns specification is a comma separated list of column names and types. Example: create table rooms ( roomid int, cat char(10), balcony boolean ) The allowed types are char num numeric int integer float boolean blob memo date time datetime Some of them are synonyms. They are of course converted to appropriate XBase types. drop table drop table table name Example: drop table passwd ATTRIBUTES
Besides standard DBI attribudes, DBD::XBase supports database handle attribute xbase_ignorememo: $dbh->{'xbase_ignorememo'} = 1; Setting it to 1 will cause subsequent tables to be opened while ignoring the memo files (dbt, fpt). So you can read dbf files for which you don't have (you have lost them, for example) the memo files. The memo fields will come out as nulls. VERSION
1.03 AVAILABLE FROM
http://www.adelton.com/perl/DBD-XBase/ AUTHOR
(c) 1997--2011 Jan Pazdziora. Contact the author at jpx dash perl at adelton dot com. SEE ALSO
perl(1); DBI(3), XBase(3); dbish(1) Translation into Japanese (older version) at http://member.nifty.ne.jp/hippo2000/perltips/DBD/XBase.htm by Kawai Takanori. perl v5.12.4 2011-08-31 DBD::XBase(3pm)