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CXLII. SQLite
Этот модуль обеспечивает доступ к встраиваемой системе управления базами
данных SQLite. Программы, использующие библиотеку SQLite, могут
использовать SQL базы данных без использования внешней системы управления
базами данных.
SQLite не является клиентской библиотекой, подключающейся к серверу базы
данных. SQLite напрямую работает с файлами базы данных на диске.
Замечание:
Более подробную информацию можно получить на сайте SQLite
(http://sqlite.org/).
Прочтите файл INSTALL, поставляемый с исходными тестами модуля. Или
просто воспользуйтесь командой установки PEAR: "pear install sqlite".
Библиотека SQLite включена, устанавливать ее дополнительно нет
необходимости.
Пользователи Windows могут загрузить скомпилированную версию модуля
SQLite здесь:
(php_sqlite.dll).
В PHP 5, модуль SQLite включен и устанавливается по умолчанию.
Для использования функций этого модуля, PHP должен быть собран с
поддержкой SQLite, или модуль должн быть подключен динамически в
php.ini.
Модуль SQLite определяет два типа ресурсов : соединение с базой данных и
результат запроса.
Функции sqlite_fetch_array() и
sqlite_current() могут принимать аргумент, задающий вид
возвращаемого массива. В качестве значения этого аргумента используется одна
из следующих констант:
Таблица 1. Константы выборки SQLite | Константа | Значение |
|---|
| SQLITE_ASSOC |
Индексами массива являются имена полей.
| | SQLITE_BOTH |
Каждому полю соответствуют два элемента массива: с числовым индексом,
являющимся порядковым номером поля, начиная с 0, и строковым индексом -
именем поля.
| | SQLITE_NUM |
Индексами массива являются порядковые номера полей, начиная с 0.
|
Поведение этих функций зависит от установок в php.ini.
Таблица 2. Директивы конфигурации SQLite | Имя | Значение по умолчанию | Изменяется |
|---|
| sqlite.assoc_case | 0 | PHP_INI_ALL |
Подробное описание констант PHP_INI_* см. в описании функции
ini_set().
Краткое разъяснение конфигурационных
директив.
- sqlite.assoc_case
int
Использование смешанного (0), верхнего
(1) или нижнего (2) регистра
символов в именах полей.
Эта директива используется в основном для обеспечения совместимости с
системами управления базами данных, в которых имена полей всегда
возвращаются в верхнем или нижнем регистре, независимо от регистра
символов, заданного в структуре базы данных.
Библиотека SQLite возвращает имена полей в точности так, как они заданы
в структуре базы данных. Если директива
sqlite.assoc_case имеет значение
0, регистр символов остается без изменения. Когда она
имеет значение 1 или 2, PHP
преобразует имена полей в верхний или нижний регистр соответственно.
Использование этой директивы немного снижает производительность, однако
это НАМНОГО быстрее, чем преобразование регистра в PHP скрипте.
SQLite
papafox888 at hotmail dot com
01-Jun-2006 09:05
If you get an error message:
Warning: sqlite_open() [function.sqlite-open]: file is encrypted or is not a database
then most probably your code is accessing a SQLite3 database.
sqlite_open() only supports SQLite2. Use PDO to access SQLite3.
Egon at example dot com
21-Feb-2006 05:15
<$php
public function set_by_db_with_join_to_users_department($col, $foo){
$list = "da.ROWID, da.dept_id, da.script, da.action, da.description, ud.name";
$query = "SELECT $list FROM dept_access AS da, users_department AS ud
WHERE da.dept_id = ud.ROWID
AND da.$col = '$foo';";
$db = new SQLiteDatabase (dept_access::db_path, 0666, &$error)
or die("Failed: $error");
$db->queryExec("ATTACH DATABASE '".dept_access::db_users_path."' AS users");
$row = $db->arrayQuery($query, SQLITE_ASSOC);
unset($db);
echo $query."\n";
echo var_dump($row);
$this->ROWID = $row[0]['da.ROWID'];
$this->dept_id = $row[0]['da.dept_id'];
$this->dept_name = $row[0]['ud.name'];
$this->script = $row[0]['da.script'];
$this->action = $row[0]['da.action'];
$this->description = $row[0]['da.description'];
}
?>
For ATTACH DATABASE to work you need to run it in a $db->queryExec(ATTACH DATABASE...); before using $db->arrayQuery. This is most likly the case with other OO methods to. This on stumped me for a while.
heinemann.juergen AT t-online.de
11-Nov-2005 09:53
Simple Example for using SQLite for small Buffering Clipboard ;)
<?php
final class SQLiteClipboard
{
private $SQL;
private $DB = "Clipboard.sqlite";
private $TB = "Clipboard";
private $ID = "ID";
private $PA = "PARAM";
private $VA = "VAL";
function __construct( $path )
{
$this->DB = chop( $path . "/" . $this->DB );
$this->sql_init();
}
private function sql_init()
{
$this->SQL = new SQLiteDatabase( $this->DB, 0660 );
if ( ! file_exists( $this->DB ) )
die( "Permission Denied!" );
$q = $this->SQL->query("PRAGMA table_info(" . $this->TB . ")");
if ( $q->numRows() == 0 ) {
$this->SQL->query( "CREATE TABLE " . $this->TB . " ( " . $this->ID . " INTEGER PRIMARY KEY, " . $this->PA . " CHAR(255), " . $this->VA . " CHAR(255) );" );
}
}
private function sql_check( $p )
{
$o = null;
$q = $this->SQL->query( "SELECT " . $this->ID . " FROM " . $this->TB . " WHERE ( " . $this->PA . "='$p' ) ORDER BY " . $this->ID . " LIMIT 1" );
while( $q->valid() ) {
$r = $q->current();
return $r[$this->ID];
$q->next();
}
return false;
}
public function __get( $p )
{
$q = $this->SQL->query( "SELECT " . $this->VA . " FROM " . $this->TB . " WHERE ( " . $this->PA . "='$p' ) ORDER BY " . $this->ID );
while( $q->valid() ) {
$r = $q->current();
$o = $r[$this->VA];
$q->next();
}
return $o;
}
public function __set( $p, $v )
{
if ( $this->sql_check( $p ) && ! empty( $v ) )
return $this->SQL->query( "UPDATE " . $this->TB . " SET " . $this->VA . "='$v' WHERE ( " . $this->PA . "='$p' );" );
elseif ( ! $this->sql_check( $p ) && ! empty( $v ) )
return $this->SQL->query( "INSERT INTO " . $this->TB . " ( " . $this->PA . ", " . $this->VA . " ) VALUES ('$p', '$v' );" );
elseif ( $this->sql_check( $p ) && empty( $v ) )
return $this->SQL->query( "DELETE FROM " . $this->TB . " WHERE ( " . $this->PA . "='$p' );" );
else
return false;
}
} ?>
31-Aug-2005 04:21
A function to check whether a table exists:
<?php
function sqlite_table_exists(&$sqlite, $table)
{
$result = $sqlite->query("SELECT name FROM sqlite_master WHERE type='table' AND name='$table'");
return $result->numRows() > 0;
}
?>
bens at effortlessis dot com
14-Jul-2005 11:37
Sqlite by default allows for foreign keys, but doesn't enforce them.
I found a nice article on how to enforce foreign keys at http://www.justatheory.com/computers/databases/sqlite/
It would be nice if this could be handled with a wrapper class, so that adding foreign keys is done thru a wrapper API to automate the generation of the necessary enforcement triggers. If nobody's done this by the time I start coding against SqlLite/PHP5 in 6-12 months, I'll write one myself, possibly by modifying "jon at jenseng dot com"s alter table wrapper
Anyway, it's not PHP specific, but anybody using Sqlite really should know this!
Stephen Leaf
30-Jun-2005 05:58
I think it would be good to point out that currently (as of 5.0.4) this extention does not support SQLite 3 databases.
So if your getting an error message like:
Error: file is encrypted or is not a database
That is why.
bart at mediawave dot nl
18-Apr-2005 07:30
SELECT tablename.columnname FROM table;
will cause SQLite to return an array having tablename.field_name as the array index. (e.g. $result['tablename.field_name'])
To let SQLite return an array having only field_name as the array index (e.g. $result['field_name']) you can issue a 'PRAGMA short_column_names = 1' query:
sqlite_query($connection_id, 'PRAGMA short_column_names = 1');
This behaviour is more consistent with the other database extensions.
For a full list of all pragmas visit: http://sqlite.org/pragma.html
dotwho at NOSPAM dot mac dot com
09-Feb-2005 06:03
This may have been obvious to others, but I had a tough time finding the info.
The default location for the actual database file is the same location of the php doc that created the database. You can alter this behavior by specifying the full path in the creation call:
<php
$db = sqlite_open("/absolute/path/my_sqlite.db");
?>
Note that if you used the default location, the db file may be served up by the webserver if it is in a the http document path. This is obviously a security risk that should be avoided.
//Max
hunreal+php at gmail dot com
16-Jan-2005 08:42
Check the db/table if exist
$db_name='db';
$db=new SQLiteDatabase($db_name, 0666, $error);
if ($error) exit($error);
$q=$db->query("PRAGMA table_info(test)");
if ($q->numRows()!=2) {
if (!@$db->queryexec("
CREATE TABLE test (
id INTEGER NOT NULL PRIMARY KEY,
text VARCHAR ( 255 ) NOT NULL
)")
) exit ("Create SQLite Database Error\n");
}
nicolas dot toniazzi at free dot fr
16-Nov-2004 07:24
The same in 3 lines.
<?php
function sqlite_table_exists($db,$mytable) {
$result = sqlite_query($db,"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='$mytable'");
$count = intval(sqlite_fetch_single($result));
return $count > 0;
}
?>
alexs at alphacomolex dot info
28-Oct-2004 03:41
the OO version.
<?php
function sqlite_table_exists($db,$mytable) {
$result = $db->query("SELECT name FROM sqlite_master WHERE type='table'");
$tables = $result->fetchAll();
if (count($tables) == 0) {
return FALSE ;
}
foreach ($tables as $table) {
if ($table['name'] == $mytable) {
return(TRUE);
}
}
return(FALSE);
}
?>
artooro at gmail dot com
21-Oct-2004 06:26
If you need to check if a table exists, you can use a function like this:
<?php
function sqlite_table_exists($mytable) {
$db = sqlite_open('mydb.sqlite', 0666, $sqliteerror);
$query = sqlite_query($db, "SELECT name FROM sqlite_master WHERE type='table'");
$tables = sqlite_fetch_array($query);
if ($tables != '') {
foreach ($tables as $table) {
if ($table == $mytable) {
return("TRUE");
}
else {
return("FALSE");
}
}
}
else {
return("FALSE");
}
}
?>
A function like this could be used to create the table if it's not already created, etc.
j-pieper at NOSPAM dot web dot de
19-Oct-2004 03:18
If you want to create a table in your database which should have an integer primary key, you cannot declare the row like this:
id int(16) primary key
or
id integer(16) primary key
When you declare it like this it could be that the id isnt auto increment. You have to declare it like this:
id integer primary key
jon at jenseng dot com
20-Jul-2004 02:50
Since SQLite doesn't support ALTER TABLE statements or renaming tables, modifying an existing table is a bit cumbersome. You have to:
1. create a temporary table
2. copy the original table into the temporary table
3. delete the original
4. recreate the original with new column definitions
5. copy the contents back
6. delete the temporary table
As this is rather unwieldy, I've created a wrapper class that allows for ALTER TABLE queries and does the dirty work for you. It has integrated error handling to ensure that queries are completely valid and it allows for complex statements such as:
ALTER TABLE foo ADD bar VARCHAR(27), DROP bar2, CHANGE bar3 foobar INTEGER, ADD bar4 DATE
Documentation:
http://code.jenseng.com/db/
Source:
http://code.jenseng.com/db/sql.txt
david at acz dot org
14-Jul-2004 06:29
You can use the PECL SQLite extension as a static (built into the executable) PHP module with PHP 4. Download the extension tarball and extract it. Move it to ext/sqlite in the PHP source directory. Delete configure and run buildconf.
Example below. Change version numbers as appropriate:
$ tar -xzvf php-4.3.8.tar.gz
$ tar -xzvf SQLite-1.0.2.tgz
$ mv SQLite-1.0.2 php-4.3.8/ext/sqlite
$ cd php-4.3.8
$ rm configure
$ ./buildconf --force
If everything worked, then you should now be able to build PHP with SQLite support:
$ ./configure --help | grep sqlite
--with-sqlite Include sqlite support
I think this method will work for other PECL extensions.
csaba at alum dot mit dot edu
14-Apr-2004 08:16
If you want to get the list of all the columns in a table (and associated information), PRAGMA is helpful (see http://sqlite.org/lang.html#pragma for details):
if (!($db=@sqlite_open("delme.db",0666,$sqliteerror))) die("Can't open database");
@sqlite_query ($db, 'DROP TABLE foo;');
sqlite_query($db, "CREATE TABLE foo (bar INTEGER PRIMARY KEY, baz VARCHAR(5));");
$aTableStruct = sqlite_array_query($db, "PRAGMA table_info('foo');", SQLITE_ASSOC);
for ($i=0,$aNames=array();$i<sizeof($aTableStruct);++$i)
$aNames[]=$aTableStruct[$i]['name'];
var_dump ($aNames); // => ['bar', 'baz']
Note also that if you want to use more than one database in the same connection using "ATTACH DATABASE ..." then you should supply the complete database filename.
Csaba Gabor
cricket at djcricket dot com
31-Mar-2004 09:30
To elaborate on vpupkin at comcast dot net's post about the INSERT query problem, you will be unable to execute any manipulation queries (INSERT/UPDATE/DELETE/ect) on the SQLite database file unless the directory the SQLite database file resides in is writable by the webserver.
The reason for this is because SQLite needs to write a lock file to the hard drive. After a processes finishes writting, it deletes the lock file. Other processes check for the lock file before writting to the SQLite database file and if present, delay writting until the lock file is no longer present.
jlsalinas at spamsucks dot gmx dot net
13-Feb-2004 06:22
For those looking for a function similar to mysql_list_tables, here you have:
if (! function_exists ('sqlite_list_tables')) {
function sqlite_list_tables (&$dblink) {
$tables = array ();
$sql = "SELECT name FROM sqlite_master WHERE (type = 'table')";
if ($res = sqlite_query ($dblink, $sql)) {
while (sqlite_has_more($res)) {
$tables[] = sqlite_fetch_single($res);
}
}
return $tables;
}
}
And a related funtion, to test if a given table exists:
if (! function_exists ('sqlite_table_exists')) {
function sqlite_table_exists (&$dblink, $table) {
$sql = "SELECT count(name) FROM sqlite_master WHERE ((type = 'table') and (name = '$table'))";
if ($res = sqlite_query ($dblink, $sql)) {
return sqlite_fetch_single($res) > 0;
} else {
return false; // or throw exception
}
}
}
Of course it would be preferable to have these functions included in the library, to avoid potential changes internal to SQLite; but we'll have to stick to this method until then.
vpupkin at comcast dot net
30-Nov-2003 08:53
if you are going to send INSERT queries, you will need to make the folder, where you put your "file.db", writable by a web server user, otherwise you'll receive error message - "Unable to open database . . . ". File permissions are not enough (phpinfo - SQLite Lib 2.8.3)
Minots Estich <minots at D0X dot de>
21-Nov-2003 06:47
If you gone in trouble while/with installation of sqlite,
you can try the installation steps Ive done at
RedHat9 with PHP4.3.4 and Apache 1.3.28
via the Linux shell:
# wget http://pecl.php.net/get/SQLite-1.0.tgz
# tar xzf SQLite-1.0.tgz
# cd sqlite
# export PHP_PREFIX="/usr"
# $PHP_PREFIX/bin/phpize
# ./configure
# make
# make install
After that add following to php.ini and restart Apache:
[sqlite]
extension="sqlite.so"
ng4rrjanbiah at rediffmail dot com
07-Nov-2003 07:19
Very nice MS PowerPoint presentation titled "SQLite and PHP" (author: Wez Furlong) can be downloaded at ~wez/SQLite_and_PHP.ppt [134 KB]
HTH,
R. Rajesh Jeba Anbiah
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