DBD::XBase(3) User Contributed Perl Documentation DBD::XBase(3)NAMEDBD::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 usefull
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 ALSOperl(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 v5.14.1 2011-03-06 DBD::XBase(3)
