    $ 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 驅動程序，那么可按照以下步驟進行安裝：

    $ 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

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)庫的需求。如果您需要了解更多細節(jié)，請查看 Perl DBI 官方文檔。

序號	API & 描述
1	DBI->connect($data_source, "", "", \%attr) 建立一個到被請求的 $data_source 的數(shù)據(jù)庫連接或者 session。如果連接成功，則返回一個數(shù)據(jù)庫處理對象。數(shù)據(jù)源形式如下所示：DBI:SQLite:dbname='test.db'。其中，SQLite 是 SQLite 驅動程序名稱，test.db 是 SQLite 數(shù)據(jù)庫文件的名稱。如果文件名 filename 賦值為 ':memory:'，那么它將會在 RAM 中創(chuàng)建一個內存數(shù)據(jù)庫，這只會在 session 的有效時間內持續(xù)。如果文件名 filename 為實際的設備文件名稱，那么它將使用這個參數(shù)值嘗試打開數(shù)據(jù)庫文件。如果該名稱的文件不存在，那么將創(chuàng)建一個新的命名為該名稱的數(shù)據(jù)庫文件。您可以保留第二個和第三個參數(shù)為空白字符串，最后一個參數(shù)用于傳遞各種屬性，詳見下面的實例講解。
2	$dbh->do($sql) 該例程準備并執(zhí)行一個簡單的 SQL 語句。返回受影響的行數(shù)，如果發(fā)生錯誤則返回 undef。返回值 -1 意味著行數(shù)未知，或不適用，或不可用。在這里，$dbh 是由 DBI->connect() 調用返回的處理。
3	$dbh->prepare($sql) 該例程為數(shù)據(jù)庫引擎后續(xù)執(zhí)行準備一個語句，并返回一個語句處理對象。
4	$sth->execute() 該例程執(zhí)行任何執(zhí)行預準備的語句需要的處理。如果發(fā)生錯誤則返回 undef。如果成功執(zhí)行，則無論受影響的行數(shù)是多少，總是返回 true。在這里，$sth 是由 $dbh->prepare($sql) 調用返回的語句處理。
5	$sth->fetchrow_array() 該例程獲取下一行數(shù)據(jù)，并以包含各字段值的列表形式返回。在該列表中，Null 字段將作為 undef 值返回。
6	$DBI::err 這相當于 $h->err。其中，$h 是任何的處理類型，比如 $dbh、$sth 或 $drh。該程序返回最后調用的驅動程序（driver）方法的數(shù)據(jù)庫引擎錯誤代碼。
7	$DBI::errstr 這相當于 $h->errstr。其中，$h 是任何的處理類型，比如 $dbh、$sth 或 $drh。該程序返回最后調用的 DBI 方法的數(shù)據(jù)庫引擎錯誤消息。
8	$dbh->disconnect() 該例程關閉之前調用 DBI->connect() 打開的數(shù)據(jù)庫連接。

連接數(shù)據(jù)庫

下面的 Perl 代碼顯示了如何連接到一個現(xiàn)有的數(shù)據(jù)庫。如果數(shù)據(jù)庫不存在，那么它就會被創(chuàng)建，最后將返回一個數(shù)據(jù)庫對象。

    #!/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 successfullyn";

現(xiàn)在，讓我們來運行上面的程序，在當前目錄中創(chuàng)建我們的數(shù)據(jù)庫 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)庫成功創(chuàng)建，那么會顯示下面所示的消息：

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

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)庫中創(chuàng)建一個表：

    #!/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 successfullyn";

    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 successfullyn";
    }
    $dbh->disconnect();

上述程序執(zhí)行時，它會在 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.

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 successfullyn";

    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 successfullyn";
    $dbh->disconnect();

上述程序執(zhí)行時，它會在 COMPANY 表中創(chuàng)建給定記錄，并會顯示以下兩行：

    Opened database successfully
    Records created successfully

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 successfullyn";

    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] ."nn";
    }
    print "Operation done successfullyn";
    $dbh->disconnect();

上述程序執(zhí)行時，它會產生以下結果：

    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

UPDATE 操作

下面的 Perl 代碼顯示了如何使用 UPDATE 語句來更新任何記錄，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 successfullyn";

    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 : $rvn";
    }
    $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] ."nn";
    }
    print "Operation done successfullyn";
    $dbh->disconnect();

上述程序執(zhí)行時，它會產生以下結果：

    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

DELETE 操作

下面的 Perl 代碼顯示了如何使用 DELETE 語句刪除任何記錄，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 successfullyn";

    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 : $rvn";
    }
    $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] ."nn";
    }
    print "Operation done successfullyn";
    $dbh->disconnect();

上述程序執(zhí)行時，它會產生以下結果：

    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

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