sqlite perl 編程接口

1. 安裝

sqlite3 可使用 perl dbi 模塊與 perl 進(jìn)行集成。perl dbi 模塊是 perl 編程語(yǔ)言的數(shù)據(jù)庫(kù)訪問模塊。它定義了一組提供標(biāo)準(zhǔn)數(shù)據(jù)庫(kù)接口的方法、變量及規(guī)則。

下面顯示了在 linux/unix 機(jī)器上安裝 dbi 模塊的簡(jiǎn)單步驟：

$ wget http://search.cpan.org/cpan/authors/id/t/ti/timb/dbi-1.625.tar.gz
$ tar xvfz dbi-1.625.tar.gz
$ cd dbi-1.625
$ perl makefile.pl
$ make
$ make install

如果您需要為 dbi 安裝 sqlite 驅(qū)動(dòng)程序，那么可按照以下步驟進(jìn)行安裝：

$ wget http://search.cpan.org/cpan/authors/id/m/ms/msergeant/dbd-sqlite-1.11.tar.gz
$ tar xvfz dbd-sqlite-1.11.tar.gz
$ cd dbd-sqlite-1.11
$ perl makefile.pl
$ make
$ make install

2. dbi 接口 api

以下是重要的 dbi 程序，可以滿足您在 perl 程序中使用 sqlite 數(shù)據(jù)庫(kù)的需求。如果您需要了解更多細(xì)節(jié)，請(qǐng)查看 perl dbi 官方文檔。

3. 連接數(shù)據(jù)庫(kù)

下面的 perl 代碼顯示了如何連接到一個(gè)現(xiàn)有的數(shù)據(jù)庫(kù)。如果數(shù)據(jù)庫(kù)不存在，那么它就會(huì)被創(chuàng)建，最后將返回一個(gè)數(shù)據(jù)庫(kù)對(duì)象。

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite"; 
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 }) 
                      or die $dbi::errstr;

print "opened database successfully\n";

現(xiàn)在，讓我們來(lái)運(yùn)行上面的程序，在當(dāng)前目錄中創(chuàng)建我們的數(shù)據(jù)庫(kù) test.db。您可以根據(jù)需要改變路徑。保存上面代碼到 sqlite.pl 文件中，并按如下所示執(zhí)行。如果數(shù)據(jù)庫(kù)成功創(chuàng)建，那么會(huì)顯示下面所示的消息：

$ chmod +x sqlite.pl
$ ./sqlite.pl
open database successfully

4. 創(chuàng)建表

下面的 perl 代碼段將用于在先前創(chuàng)建的數(shù)據(jù)庫(kù)中創(chuàng)建一個(gè)表：

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite";
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 })
                      or die $dbi::errstr;
print "opened database successfully\n";

my $stmt = qq(create table company
      (id int primary key     not null,
       name           text    not null,
       age            int     not null,
       address        char(50),
       salary         real););
my $rv = $dbh->do($stmt);
if($rv < 0){
   print $dbi::errstr;
} else {
   print "table created successfully\n";
}
$dbh->disconnect();

上述程序執(zhí)行時(shí)，它會(huì)在 test.db 中創(chuàng)建 company 表，并顯示下面所示的消息：

opened database successfully
table created successfully

注意：如果您在任何操作中遇到了下面的錯(cuò)誤： in case you see following error in any of the operation:

dbd::sqlite::st execute failed: not an error(21) at dbdimp.c line 398

在這種情況下，您已經(jīng)在 dbd-sqlite 安裝中打開了可用的 dbdimp.c 文件，找到 sqlite3_prepare() 函數(shù)，并把它的第三個(gè)參數(shù) 0 改為 -1。最后使用 make 和 make install 安裝 dbd::sqlite，即可解決問題。 in this case you will have open dbdimp.c file available in dbd-sqlite installation and find out sqlite3_prepare() function and change its third argument to -1 instead of 0. finally install dbd::sqlite using make and do make install to resolve the problem.

5. insert 操作

下面的 perl 程序顯示了如何在上面創(chuàng)建的 company 表中創(chuàng)建記錄：

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite";
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 })
                      or die $dbi::errstr;
print "opened database successfully\n";

my $stmt = qq(insert into company (id,name,age,address,salary)
      values (1, 'paul', 32, 'california', 20000.00 ));
my $rv = $dbh->do($stmt) or die $dbi::errstr;

$stmt = qq(insert into company (id,name,age,address,salary)
      values (2, 'allen', 25, 'texas', 15000.00 ));
$rv = $dbh->do($stmt) or die $dbi::errstr;

$stmt = qq(insert into company (id,name,age,address,salary)
      values (3, 'teddy', 23, 'norway', 20000.00 ));
$rv = $dbh->do($stmt) or die $dbi::errstr;

$stmt = qq(insert into company (id,name,age,address,salary)
      values (4, 'mark', 25, 'rich-mond ', 65000.00 ););
$rv = $dbh->do($stmt) or die $dbi::errstr;

print "records created successfully\n";
$dbh->disconnect();

上述程序執(zhí)行時(shí)，它會(huì)在 company 表中創(chuàng)建給定記錄，并會(huì)顯示以下兩行：

opened database successfully
records created successfully

6. select 操作

下面的 perl 程序顯示了如何從前面創(chuàng)建的 company 表中獲取并顯示記錄：

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite";
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 })
                      or die $dbi::errstr;
print "opened database successfully\n";

my $stmt = qq(select id, name, address, salary  from company;);
my $sth = $dbh->prepare( $stmt );
my $rv = $sth->execute() or die $dbi::errstr;
if($rv < 0){
   print $dbi::errstr;
}
while(my @row = $sth->fetchrow_array()) {
      print "id = ". $row[0] . "\n";
      print "name = ". $row[1] ."\n";
      print "address = ". $row[2] ."\n";
      print "salary =  ". $row[3] ."\n\n";
}
print "operation done successfully\n";
$dbh->disconnect();

上述程序執(zhí)行時(shí)，它會(huì)產(chǎn)生以下結(jié)果：

opened database successfully
id = 1
name = paul
address = california
salary =  20000

id = 2
name = allen
address = texas
salary =  15000

id = 3
name = teddy
address = norway
salary =  20000

id = 4
name = mark
address = rich-mond
salary =  65000

operation done successfully

7. update 操作

下面的 perl 代碼顯示了如何使用 update 語(yǔ)句來(lái)更新任何記錄，然后從 company 表中獲取并顯示更新的記錄：

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite";
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 })
                      or die $dbi::errstr;
print "opened database successfully\n";

my $stmt = qq(update company set salary = 25000.00 where id=1;);
my $rv = $dbh->do($stmt) or die $dbi::errstr;
if( $rv < 0 ){
   print $dbi::errstr;
}else{
   print "total number of rows updated : $rv\n";
}
$stmt = qq(select id, name, address, salary  from company;);
my $sth = $dbh->prepare( $stmt );
$rv = $sth->execute() or die $dbi::errstr;
if($rv < 0){
   print $dbi::errstr;
}
while(my @row = $sth->fetchrow_array()) {
      print "id = ". $row[0] . "\n";
      print "name = ". $row[1] ."\n";
      print "address = ". $row[2] ."\n";
      print "salary =  ". $row[3] ."\n\n";
}
print "operation done successfully\n";
$dbh->disconnect();

上述程序執(zhí)行時(shí)，它會(huì)產(chǎn)生以下結(jié)果：

opened database successfully
total number of rows updated : 1
id = 1
name = paul
address = california
salary =  25000

id = 2
name = allen
address = texas
salary =  15000

id = 3
name = teddy
address = norway
salary =  20000

id = 4
name = mark
address = rich-mond
salary =  65000

operation done successfully

8. delete 操作

下面的 perl 代碼顯示了如何使用 delete 語(yǔ)句刪除任何記錄，然后從 company 表中獲取并顯示剩余的記錄：

#!/usr/bin/perl

use dbi;
use strict;

my $driver   = "sqlite";
my $database = "test.db";
my $dsn = "dbi:$driver:dbname=$database";
my $userid = "";
my $password = "";
my $dbh = dbi->connect($dsn, $userid, $password, { raiseerror => 1 })
                      or die $dbi::errstr;
print "opened database successfully\n";

my $stmt = qq(delete from company where id=2;);
my $rv = $dbh->do($stmt) or die $dbi::errstr;
if( $rv < 0 ){
   print $dbi::errstr;
}else{
   print "total number of rows deleted : $rv\n";
}
$stmt = qq(select id, name, address, salary  from company;);
my $sth = $dbh->prepare( $stmt );
$rv = $sth->execute() or die $dbi::errstr;
if($rv < 0){
   print $dbi::errstr;
}
while(my @row = $sth->fetchrow_array()) {
      print "id = ". $row[0] . "\n";
      print "name = ". $row[1] ."\n";
      print "address = ". $row[2] ."\n";
      print "salary =  ". $row[3] ."\n\n";
}
print "operation done successfully\n";
$dbh->disconnect();

上述程序執(zhí)行時(shí)，它會(huì)產(chǎn)生以下結(jié)果：

opened database successfully
total number of rows deleted : 1
id = 1
name = paul
address = california
salary =  25000

id = 3
name = teddy
address = norway
salary =  20000

id = 4
name = mark
address = rich-mond
salary =  65000

operation done successfully