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sybperl-l Archive
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From: David Hajoglou <hojo at greenland dot i-tel dot com>
Subject: Re: Help pls.
Date: Oct 6 1999 5:32PM
* NAME
* SYNOPSIS
* DESCRIPTION
+ Attributes
+ DateTime, Money and Numeric data behavior
+ Compatibility with Sybase Open Client documentation.
* Sybase::DBlib
+ TEXT/IMAGE Routines
+ BCP Routines:
+ Attributes:
+ Status Variables
+ Examples
* Sybase::Sybperl
* Sybase::CTlib
+ DESCRIPTION
+ EXAMPLES
+ ATTRIBUTES
* Using ct_get_data() and ct_send_data() to do raw TEXT processing
+ Retrieving TEXT columns using ct_get_data()
+ Updating TEXT columns using ct_send_data()
* Common Sybase::DBlib and Sybase::CTlib routines
* Special handling of DATETIME, MONEY & NUMERIC/DECIMAL values
* BUGS
* ACKNOWLEDGEMENTS
* AUTHORS
_________________________________________________________________
NAME
sybperl - Sybase extensions to Perl
_________________________________________________________________
SYNOPSIS
use Sybase::DBlib;
use Sybase::CTlib;
use Sybase::Sybperl;
_________________________________________________________________
DESCRIPTION
Sybperl implements three Sybase extension modules to perl (version
5.002 or higher). Sybase::DBlib adds a subset of the Sybase DB-Library
API. Sybase::CTlib adds a subset of the Sybase CT-Library (aka the
Client Library) API. Sybase::Sybperl is a backwards compatibility
module (implemented on top of Sybase::DBlib) to enable scripts written
for sybperl 1.0xx to run with Perl 5. Using both the Sybase::Sybperl
and Sybase::DBlib modules explicitly in a single script is not
garanteed to work correctly.
The general usage format for both Sybase::DBlib and Sybase::CTlib is
this:
use Sybase::DBlib;
# Allocate a new connection, usually refered to as a database handle
$dbh = new Sybase::DBlib username, password;
# Set an attribute for this dbh:
$dbh->{UseDateTime} = TRUE;
# Call a method with this dbh:
$dbh->dbcmd(sql code);
The DBPROCESS or CS_CONNECTION that is opened with the call to new()
is automatically closed when the $dbh goes out of scope:
sub run_a_query {
my $dbh = new Sybase::CTlib $user, $passwd;
my @dat = $dbh->ct_sql("select * from sysusers");
return @dat;
}
# The $dbh is automatically closed when we exit the subroutine.
It should be noted that an important difference between CTlib and
DBlib is in how the SYBASE environment variable is handled. DBlib only
checks for the SYBASE variable when it requires access to the
interfaces file. This allows for definition of the SYBASE variable in
your script. CTlib requires that the SYBASE variable be defined BEFORE
initialization. If the variable is not defined then CTlib will not
initialize properly and your script will not run.
_________________________________________________________________
Attributes
The Sybase::DBlib and Sybase::CTlib modules make a use of attributes
that are either package global or associated with a specific $dbh.
These attributes control certain behavior aspects, and are also used
to store status information.
Package global attributes can be set using the %Att hash table in
either modules. The %Att variable is not exported, so it must be fully
qualified:
$Sybase::DBlib::Att{UseDateTime} = TRUE;
NOTE: setting an attribute via the %Att variable does NOT change the
status of currently allocated database handles.
In this version, the available attributes for a $dbh are set when the
$dbh is created. You can't add arbitrary attributes during the life of
the $dbh. This has been done to implement a stricter behavior and to
catch attribute errors.
It is possible to add your own attributes to a $dbh at creation time.
The Sybase::BCP module adds two attributes to the normal Sybase::DBlib
attribute set by passing an additional attribute variable to the
Sybase::DBlib new() call:
$d = new Sybase::DBlib $user,$passwd,
$server,$appname, {Global => {}, Cols => {}};
_________________________________________________________________
DateTime, Money and Numeric data behavior
As of version 2.04, the Sybase DATETIME and MONEY datatypes can be
kept in their native formats in both the Sybase::DBlib and
Sybase::CTlib modules. In addition, NUMERIC or DECIMAL values can also
be kept in their native formats when using the Sybase::CTlib module.
This behavior is normally turned off by default, because there is a
performance penalty associated with it. It is turned on by using
package or database handle specific attributes.
Please see the discussion on Special handling of DATETIME, MONEY &
NUMERIC/DECIMAL values below for details.
_________________________________________________________________
Compatibility with Sybase Open Client documentation.
In general, I have tried to make the calls in this package behave the
same way as their C language equivalents. In certain cases the
parameters are different, and certain calls (dblogin() for example)
don't do the same thing in C as in Perl. This has been done to make
the life of the Perl programmer easier.
You should if possible have the Sybase Open Client documentation
available when writing Sybperl programs.
_________________________________________________________________
Sybase::DBlib
A generic perl script using Sybase::DBlib would look like this:
use Sybase::DBlib;
$dbh = new Sybase::DBlib 'sa', $pwd, $server, 'test_app';
$dbh->dbcmd("select * from sysprocesses\n");
$dbh->dbsqlexec;
$dbh->dbresults;
while(@data = $dbh->dbnextrow)
{
.... do something with @data ....
}
The API calls that have been implemented use the same calling sequence
as their C equivalents, with a couple of exceptions, detailed below.
Please see also Common Sybase::DBlib and Sybase::CTlib routines below.
List of API calls
Standard Routines:
$dbh = new Sybase::DBlib [$user [, $server [, $appname [, {additional
attributes}]]]]
$dbh = Sybase::DBlib->dblogin([$user [, $pwd [, $server [, $appname,
[{additional attributes}] ]]]])
Initiates a connection to a Sybase dataserver, using the
supplied user, password, server and application name
information. Uses the default values (see DBSETLUSER(),
DBSETLPWD(), etc. in the Sybase DB-library documentation) if
the parameters are ommitted.
Both forms of the call are identical.
This call can be used multiple times if connecting to multiple
servers with different username/password combinations is
required, for example.
The additional attributes parameter allows you to define
application specific attributes that you wish to associate with
the $dbh.
$dbh = Sybase::DBlib->dbopen([$server [, $appname, [{attributes}] ]])
Open an additional connection, using the current LOGINREC
information.
$status = $dbh->dbuse($database)
Executes ``use database $database'' for the connection $dbh.
$status = $dbh->dbcmd($sql_cmd)
Appends the string $sql_cmd to the current command buffer of
this connection.
$status = $dbh->dbsqlexec
Sends the content of the current command buffer to the
dataserver for execution. See the DB-library documentation for
a discussion of return values.
$status = $dbh->dbresults
Retrieves result information from the dataserver after having
executed dbsqlexec().
$status = $dbh->dbsqlsend
Send the command batch to the server, but do not wait for the
server to return any results. Should be followed by calls to
dbpoll() and dbsqlok(). See the Sybase docs for further
details.
$status = $dbh->dbsqlok
Wait for results from the server and verify the correctness of
the instructions the server is responding to. Mainly for use
with dbmoretext() in Sybase::DBlib. See also the Sybase
documentation for details.
($dbproc, $reason) = Sybase::DBlib->dbpoll($millisecs)
($dbproc, $reason) = $dbh->dbpoll($millisecs)
Note: The dbpoll() syntax has been changed since sybperl
2.09_05.
Poll the server to see if any connection has results pending.
Used in conjunction with dbsqlsend() and dbsqlok() to perform
asynchronous queries. dbpoll() will wait up to $millisecs
milliseconds and poll any open DBPROCESS for results (if called
as Sybase::DBlib->dbpoll()) or poll the specified DBPROCESS (if
called as $dbh->dbpoll()). If it finds a DBPROCESS that is
ready it returns it, along with the reason why it's ready. If
dbpoll() times out, or if an interupt occurs $dbproc will be
undefined, and $reason will be either DBTIMEOUT or DBINTERUPT.
If $millisecs is 0 then dbpoll() returns immediately. If
$millisecs is -1 then it will not return until either results
are pending or a system interupt has occured. Please see the
Sybase documentation for further details.
Here is an example of using dbsqlsend(), dbpoll() and
dbsqlok():
$dbh->dbcmd("exec big_hairy_query_proc");
$dbh->dbsqlsend;
# here you can go do something else...
# now - find out if some results are waiting
($dbh2, $reason) = $dbh->dbpoll(100);
if($dbh2 && $reason == DBRESULT) { # yes! - there's data on the pipe
$dbh2->dbsqlok;
while($dbh2->dbresults != NO_MORE_RESULTS) {
while(@dat = $dbh2->dbnextrow) {
....
}
}
}
$status = $dbh->dbcancel
Cancels the current command batch.
$status = $dbh->dbcanquery
Cancels the current query within the currently executing
command batch.
$dbh->dbfreebuf
Free the command buffer (required only in special cases - if
you don't know what this is you probably don't need it :-)
$dbh->dbclose
Force the closing of a connection. Note that connections are
automatically closed when the $dbh goes out of scope.
$dbh->DBDEAD
Returns TRUE if the DBPROCESS has been marked DEAD by
DBlibrary.
$status = $dbh->DBCURCMD
Returns the number of the currently executing command in the
command batch. The first command is number 1.
$status = $dbh->DBMORECMDS
Returns TRUE if there are additional commands to be executed in
the current command batch.
$status = $dbh->DBCMDROW
Returns SUCCEED if the current command can return rows.
$status = $dbh->DBROWS
Returns SUCCEED if the current command did return rows
$status = $dbh->DBCOUNT
Returns the number of rows that the current command affected.
$row_num = $dbh->DBCURROW
Returns the number (counting from 1) of the currently retrieved
row in the current result set.
$spid = $dbh->dbspid
Returns the SPID (server process ID) of the current connection
to the Sybase server.
$status = $dbh->dbhasretstat
Did the last executed stored procedure return a status value?
dbhasretstats must only be called after dbresults returns
NO_MORE_RESULTS, ie after all the selet, insert, update
operations of he sored procedure have been processed.
$status = $dbh->dbretstatus
Retrieve the return status of a stored procedure. As with
dbhasretstat, call this function after all the result sets of
the stored procedure have been processed.
$status = $dbh->dbnumcols
How many columns are in the current result set.
$status = $dbh->dbcoltype($colid)
What is the column type of column $colid in the current result
set.
$type = $dbh->dbprtype($colid)
Returns the column type as a printable string.
$status = $dbh->dbcollen($colid)
What is the length (in bytes) of column $colid in the current
result set.
$string = $dbh->dbcolname($colid)
What is the name of column $colid in the current result set.
@dat = $dbh->dbnextrow([$doAssoc [, $wantRef]])
Retrieve one row. dbnextrow() returns an array of scalars, one
for each column value. If $doAssoc is non-0, then dbnextrow()
returns a hash (aka associative array) with column name/value
pairs. This relieves the programmer from having to call
dbbind() or dbdata().
If $wantRef is non-0, then dbnextrow() returns a reference to a
hash or an array. This reference points to a static array (or
hash) so if you wish to store the returned rows in an array,
you must copy the array/hash:
while($d = $dbh->dbnextrow(0, 1)) {
push(@rows, [@$d]);
}
The return value of the C version of dbnextrow() can be
accessed via the Perl DBPROCESS attribute field, as in:
@arr = $dbh->dbnextrow; # read results
if($dbh->{DBstatus} != REG_ROW) {
take some appropriate action...
}
When the results row is a COMPUTE row, the ComputeID field of
the DBPROCESS is set:
@arr = $dbh->dbnextrow; # read results
if($dbh->{ComputeID} != 0) { # it's a 'compute by' row
take some appropriate action...
}
dbnextrow() can also return a hash keyed on the column name:
$dbh->dbcmd("select Name=name, Id = id from test_table");
$dbh->dbsqlexec; $dbh->dbresults;
while(%arr = $dbh->dbnextrow(1)) {
print "$arr{Name} : $arr{Id}\n";
}
@dat = $dbh->dbretdata[$doAssoc])
Retrieve the value of the parameters marked as 'OUTPUT' in a
stored procedure. If $doAssoc is non-0, then retrieve the data
as an associative array with parameter name/value pairs.
$bylist = $dbh->dbbylist($computeID)
Returns the by list for a compute by clause. $bylist is a
reference to an array of colids. You can use $dbh->dbcolname()
to get the column names.
$dbh->dbcmd("select * from sysusers order by uid compute count(uid) by uid"
);
$dbh->dbsqlexec;
$dbh->dbresults;
my @dat;
while(@dat = $dbh->dbnextrow) {
if($dbh->{ComputeID} != 0) {
my $bylist = $dbh->dbbylist($dbh->{ComputeID});
print "bylist = @$bylist\n";
}
print "@dat\n";
}
%hash = $dbh->dbcomputeinfo($computeID, $column)
Returns a hash with the colid, op, len, type and utype of the
compute by column. You can call this subroutine to get the
information returned by DBlibrary's dbalt*() calls. The $column
is the column number in the current compute by row (starting at
1) and the $computeID is best retrieved from $dbh-{ComputeID}>.
Please see the documentation of the dbalt*() calls in Sybase's
DBlibrary manual.
$string = $dbh->dbstrcpy
Retrieve the contents of the command buffer.
$ret = $dbh->dbsetopt($opt [, $c_val [, $i_val]])
Sets option $opt with optional character parameter $c_val and
optional integer parameter $i_val. $opt is one of the option
values defined in the Sybase DBlibrary manual (f.eg.
DBSHOWPLAN, DBTEXTSIZE). For example, to set SHOWPLAN on, you
would use
$dbh->dbsetopt(DBSHOWPLAN);
See also dbclropt() and dbisopt() below.
$ret = $dbh->dbclropt($opt [, $c_val])
Clears the option $opt, previously set using dbsetopt().
$ret = $dbh->dbisopt($opt [, $c_val])
Returns TRUE if the option $opt is set.
$string = $dbh->dbsafestr($string [,$quote_char])
Convert $string to a 'safer' version by inserting single or
double quotes where appropriate, so that it can be passed to
the dataserver without syntax errors.
The second argument to dbsafestr() (normally DBSINGLE, DBDOUBLE
or DBBOTH) has been replaced with a literal ' or `` (meaning
DBSINGLE or DBDOUBLE, respectively). Omitting this argument
means DBBOTH.
$packet_size = $dbh->dbgetpacket
Returns the TDS packet size currently in use for this $dbh.
_________________________________________________________________
TEXT/IMAGE Routines
$status = $dbh->dbwritetext($colname, $dbh_2, $colnum, $text [, $log])
Insert or update data in a TEXT or IMAGE column. The usage is a
bit different from that of the C version:
The calling sequence is a little different from the C version,
and logging is off by default:
$dbh_2 and $colnum are the DBPROCESS and column number of a
currently active query. Example:
$dbh_2->dbcmd('select the_text, t_index from text_table where t_index = 5');
$dbh_2->dbsqlexec; $dbh_2->dbresults;
@data = $dbh_2->dbnextrow;
$d->dbwritetext ("text_table.the_text", $dbh_2, 1,
"This is text which was added with Sybperl", TRUE);
$status = $dbh->dbpreptext($colname, $dbh_2, $colnum, $size [, $log])
Prepare to insert or update text with dbmoretext().
The calling sequence is a little different from the C version,
and logging is off by default:
$dbh_2 and $colnum are the DBPROCESS and column number of a
currently active query. Example:
$dbh_2->dbcmd('select the_text, t_index from text_table where t_index = 5');
$dbh_2->dbsqlexec; $dbh_2->dbresults;
@data = $dbh_2->dbnextrow;
$size = length($data1) + length($data2);
$d->dbpreptext ("text_table.the_text", $dbh_2, 1, $size, TRUE);
$dbh->dbsqlok;
$dbh->dbresults;
$dbh->dbmoretext(length($data1), $data1);
$dbh->dbmoretext(length($data2), $data2);
$dbh->dbsqlok;
$dbh->dbresults;
$status = $dbh->dbmoretext($size, $data)
Sends a chunk of TEXT/IMAGE data to the server. See the example
above.
$status = $dbh->dbreadtext($buf, $size)
Read a TEXT/IMAGE data item in $size chunks.
Example:
$dbh->dbcmd("select data from text_test where id=1");
$dbh->dbsqlexec;
while($dbh->dbresults != NO_MORE_RESULTS) {
my $bytes;
my $buf = '';
while(($bytes = $dbh->dbreadtext($buf, 512)) != NO_MORE_ROWS) {
if($bytes == -1) {
die "Error!";
} elsif ($bytes == 0) {
print "End of row\n";
} else {
print "$buf";
}
}
}
_________________________________________________________________
BCP Routines:
See also the Sybase::BCP module.
BCP_SETL($state)
This is an exported routine (ie it can be called without a $dbh
handle) which sets the BCP IN flag to TRUE/FALSE.
It is necessary to call BCP_SETL(TRUE) before opening the
connection with which one wants to run a BCP IN operation.
$state = bcp_getl
Retrieve the current BCP flag status.
$status = $dbh->bcp_init($table, $hfile, $errfile, $direction)
Initialize BCP library. $direction can be DB_OUT or DB_IN
$status = $dbh->bcp_meminit($numcols)
This is a utility function that does not exist in the normal
BCP API. It's use is to initialize some internal variables
before starting a BCP operation from program variables into a
table. This call avoids setting up translation information for
each of the columns of the table being updated, obviating the
use of the bcp_colfmt call.
See EXAMPLES, below.
$status = $dbh->bcp_sendrow(LIST)
$status = $dbh->bcp_sendrow(ARRAY_REF)
Sends the data in LIST to the server. The LIST is assumed to
contain one element for each column being updated. To send a
NULL value set the appropriate element to the Perl undef value.
In the second form you pass an array reference instead of
passing the LIST, which makes processing a little bit faster on
wide tables.
$rows = $dbh->bcp_batch
Commit rows to the database. You usually use it like this:
while() {
chop;
@data = split(/\|/);
$d->bcp_sendrow(\@data); # Pass the array reference
# Commit data every 100 rows.
if((++$count % 100) == 0) {
$d->bcp_batch;
}
}
$status = $dbh->bcp_done
$status = $dbh->bcp_control($field, $value)
$status = $dbh->bcp_columns($colcount)
$status = $dbh->bcp_colfmt($host_col, $host_type, $host_prefixlen,
$host_collen, $host_term, $host_termlen, $table_col [,
$precision, $scale])
If you have DBlibrary for System 10 or higher, then you can
pass the additional $precision and $scale parameters, and have
sybperl call bcp_colfmt_ps() instead of bcp_colfmt().
$status = $dbh->bcp_collen($varlen, $table_column)
$status = $dbh->bcp_exec
$status = $dbh->bcp_readfmt($filename)
$status = $dbh->bcp_writefmt($filename)
Please see the DB-library documentation for these calls.
DBMONEY Routines:
NOTE: In this version it is possible to avoid calling the routines
below and still get DBMONEY calculations done with the correct
precision. See the Sybase::DBlib::Money discussion below.
($status, $sum) = $dbh->dbmny4add($m1, $m2)
$status = $dbh->dbmny4cmp($m1, $m2)
($status, $quotient) = $dbh->dbmny4divide($m1, $m2)
($status, $dest) = $dbh->dbmny4minus($source)
($status, $product) = $dbh->dbmny4mul($m1, $m2)
($status, $difference) = $dbh->dbmny4sub($m1, $m2)
($status, $ret) = $dbh->dbmny4zero
($status, $sum) = $dbh->dbmnyadd($m1, $m2)
$status = $dbh->dbmnycmp($m1, $m2)
($status, $ret) = $dbh->dbmnydec($m1)
($status, $quotient) = $dbh->dbmnydivide($m1, $m2)
($status, $ret, $remainder) = $dbh->dbmnydown($m1, $divisor)
($status, $ret) = $dbh->dbmnyinc($m1)
($status, $ret, $remain) = $dbh->dbmnyinit($m1, $trim)
($status, $ret) = $dbh->dbmnymaxneg
($status, $ret) = $dbh->dbmnymaxpos
($status, $dest) = $dbh->dbmnyminus($source)
($status, $product) = $dbh->dbmnymul($m1, $m2)
($status, $m1, $digits, $remain) = $dbh->dbmnyndigit($m1)
($status, $ret) = $dbh->dbmnyscale($m1, $multiplier, $addend)
($status, $difference) = $dbh->dbmnysub($m1, $m2)
($status, $ret) = $dbh->dbmnyzero
All of these routines correspond to their DB-library
counterpart, with the following exception:
The routines which in the C version take pointers to arguments
(in order to return values) return these values in an array
instead:
status = dbmnyadd(dbproc, m1, m2, &result) becomes
($status, $result) = $dbproc->dbmnyadd($m1, $m2)
RPC Routines:
NOTE: Check out eg/rpc-example.pl for an example on how to use these
calls.
$dbh->dbrpcinit($rpcname, $option)
Initialize an RPC call to the remote procedure $rpcname. See
the DB-library manual for valid values for $option.
$dbh->dbrpcparam($parname, $status, $type, $maxlen, $datalen, $value)
Add a parameter to an RPC call initiated with dbrpcinit().
Please see the DB-library manual page for details & values for
the parameters.
NOTE: All floating point types (MONEY, FLOAT, REAL, DECIMAL,
etc.) are converted to FLOAT before being sent to the RPC.
$dbh->dbrpcsend
Execute an RPC initiated with dbrpcinit().
NOTE: This call executes both dbrpcsend() and dbsqlok(). You
can call $dbh->dbresults direcly after calling $dbh->dbrpcsend.
dbrpwset($srvname, $pwd)
Set the password for connecting to a remote server.
dbrpwclr
Clear all remote server passwords.
Registered procedure execution:
$status = $dbh->dbreginit($proc_name)
$status = $dbh->dbreglist
$status = $dbh->dbreglist($parname, $type, $datalen, $value)
$status = $dbh->dbregexec($opt)
These routines are used to execute an OpenServer registered
procedure. Please the Sybase DBlibrary manual for a description
of what these routnines do, and how to call them.
Two Phase Commit Routines:
$dbh = Sybase::DBlib->open_commit($user, $pwd, $server, $appname)
$id = $dbh->start_xact($app_name, $xact_name, $site_count)
$status = $dbh->stat_xact($id)
$status = $dbh->scan_xact($id)
$status = $dbh->commit_xact($id)
$status = $dbh->abort_xact($id)
$dbh->close_commit
$string = Sybase::DBlib::build_xact_string($xact_name, $service_name,
$id)
$status = $dbh->remove_xact($id, $site_count)
Please see the Sybase documentation for this.
NOTE: These routines have not been thouroughly tested!
Exported Routines:
$old_handler = dberrhandle($err_handle)
$old_handler = dbmsghandle($msg_handle)
Register an error (or message) handler for DB-library to use.
Handler examples can be found in sybutil.pl in the Sybperl
distribution. Returns a reference to the previously defined
handler (or undef if none were defined). Passing undef as the
argument clears the handler.
dbsetifile($filename)
Set the name of the 'interfaces' file. This file is normally
found by DB-library in the directory pointed to by the $SYBASE
environment variable.
dbrecftos($filename)
Start recording all SQL sent to the server in file $filename.
dbversion
Returns a string identifying the version of DBlibrary that this
copy of Sybperl was built with.
DBSETLCHARSET($charset)
DBSETLNATLANG($language)
DBSETLPACKET($packet_size)
$time = DBGETTIME
$time = dbsettime($seconds)
$time = dbsetlogintime($seconds)
These utility routines are probably very seldom used. See the
DB-library manual for an explanation of their use.
dbexit
Tell DB-library that we're done. Once this call has been made,
no further activity requiring DB-library can be performed in
the current program.
Utility Routines:
These routines are not part of the DB-library API, but have been added
because they can make our life as programers easier, and exploit
certain strenghts of Perl.
$ret|@ret = $dbh->sql($cmd [, \&rowcallback [, $flag]])
Runs the sql command and returns the result as a reference to
an array of the rows. In a LIST context, return the array
itself (instead of a reference to the array). Each row is a
reference to an array of scalars.
If you provide a second parameter it is taken as a procedure to
call for each row. The callback is called with the values of
the row as parameters.
If you provide a third parameter, this is used in the call to
dbnextrow() to retrieve associative arrays rather than 'normal'
arrays for each row, and store them in the returned array. To
pass the third parameter without passing the &rowcallback value
you should pass the special value undef as second parameter:
@rows = $dbh->sql("select * from sysusers", undef, TRUE);
foreach $row_ref (@rows) {
if($$row_ref{'uid'} == 10) {
....
}
}
See also eg/sql.pl for an example.
Contributed by Gisle Aas.
NOTE: This routine loads all the data into memory. It should
not be run with a query that returns a large number of rows. To
avoid the risk of overflowing memory, you can limit the number
of rows that the query returns by setting the 'MaxRows' field
of the $dbh attribute field:
$dbh->{'MaxRows'} = 100;
This value is not set by default.
@ret = $dbh->nsql($sql [, "ARRAY" | "HASH" ] [, \&subroutine ] );
An enhanced version of the sql routine, nsql, is also
available. nsql() provides better error checking (using its
companion error and message handlers), optional deadlock retry
logic, and several options for the format of the return values.
In addition, the data can either be returned to the caller in
bulk, or processes line by line via a callback subroutine
passed as an argument (this functionality is similar to the
r_sql() method).
The arguments are an SQL command to be executed, the $type of
the data to be returned, and the callback subroutine.
if a callback subroutine is not given, then the data from the
query is returned as an array. The array returned by nsql is
one of the following:
Array of Hash References (if type eq HASH)
Array of Array References (if type eq ARRAY)
Simple Array (if type eq ARRAY, and a single column is queried
Boolean True/False value (if type ne ARRAY or HASH)
Optionally, instead of the words ``HASH'' or ``ARRAY'' a
reference of the same type can be passed as well. This is, both
of the following are equivalent:
$dbh->nsql("select col1,col2 from table","HASH");
$dbh->nsql("select col1,col2 from table",{});
For example, the following code will return an array of hash
references:
@ret = $dbh->nsql("select col1,col2 from table","HASH");
foreach $ret ( @ret ) {
print "col1 = ", $ret->{'col1'}, ", col2 = ", $ret->{'col2'}, "\n";
}
The following code will return an array of array references:
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