Is there any implementation of virtual table option in PHP...
I wish to use sqlite to reference custom formatted flat file as a table.
SQLite Functions
简介
This is an extension for the SQLite Embeddable SQL Database Engine. SQLite is a C library that implements an embeddable SQL database engine. Programs that link with the SQLite library can have SQL database access without running a separate RDBMS process.
SQLite is not a client library used to connect to a big database server. SQLite is the server. The SQLite library reads and writes directly to and from the database files on disk.
Note: For further information see the SQLite Website (» http://sqlite.org/).
Installation
Read the INSTALL file, which comes with the package. Or just use the PEAR installer with pecl install sqlite. SQLite itself is already included, You do not need to install any additional software.
Windows users may download the DLL version of the SQLite extension here: (» php_sqlite.dll).
In PHP 5, the SQLite extension and the engine itself are bundled and compiled by default. However, since PHP 5.1.0 you need to manually activate the extension in php.ini (because it is now bundled as shared). Moreover, since PHP 5.1.0 SQLite depends on PDO it must be enabled too, by adding the following lines to php.ini (in order):
extension=php_pdo.dll extension=php_sqlite.dll
SQLite 3 is supported through PDO SQLite.
Note: Windows installation for unprivileged accounts On Windows operating systems, unprivileged accounts don't have the TMP environment variable set by default. This will make sqlite create temporary files in the windows directory, which is not desirable. So, you should set the TMP environment variable for the web server or the user account the web server is running under. If Apache is your web server, you can accomplish this via a SetEnv directive in your httpd.conf file. For example:
If you are unable to establish this setting at the server level, you can implement the setting in your script:SetEnv TMP c:/tempThe setting must refer to a directory that the web server has permission to create files in and subsequently write to and delete the files it created. Otherwise, you may receive the following error message: malformed database schema - unable to open a temporary database file for storing temporary tablesputenv('TMP=C:/temp');
需求
In order to have these functions available, you must compile PHP with SQLite support, or load the SQLite extension dynamically from your php.ini.
资源类型
There are two resources used in the SQLite Interface. The first one is the database connection, the second one the result set.
预定义常量
以下常量由本扩展模块定义,因此只有在本扩展模块被编译到 PHP 中,或者在运行时被动态加载后才有效。
The functions sqlite_fetch_array() and sqlite_current() use a constant for the different types of result arrays. The following constants are defined:
-
SQLite result type constants
- SQLITE_ASSOC (int)
- Columns are returned into the array having the field name as the array index.
- SQLITE_BOTH (int)
- Columns are returned into the array having both a numerical index and the field name as the array index.
- SQLITE_NUM (int)
- Columns are returned into the array having a numerical index to the fields. This index starts with 0, the first field in the result.
A number of functions may return status codes. The following constants are defined:
-
SQLite status code constants
- SQLITE_OK (int)
- Successful result.
- SQLITE_ERROR (int)
- SQL error or missing database.
- SQLITE_INTERNAL (int)
- An internal logic error in SQLite.
- SQLITE_PERM (int)
- Access permission denied.
- SQLITE_ABORT (int)
- Callback routine requested an abort.
- SQLITE_BUSY (int)
- The database file is locked.
- SQLITE_LOCKED (int)
- A table in the database is locked.
- SQLITE_NOMEM (int)
- Memory allocation failed.
- SQLITE_READONLY (int)
- Attempt to write a readonly database.
- SQLITE_INTERRUPT (int)
- Operation terminated internally.
- SQLITE_IOERR (int)
- Disk I/O error occurred.
- SQLITE_CORRUPT (int)
- The database disk image is malformed.
- SQLITE_NOTFOUND (int)
- (Internal) Table or record not found.
- SQLITE_FULL (int)
- Insertion failed because database is full.
- SQLITE_CANTOPEN (int)
- Unable to open the database file.
- SQLITE_PROTOCOL (int)
- Database lock protocol error.
- SQLITE_EMPTY (int)
- (Internal) Database table is empty.
- SQLITE_SCHEMA (int)
- The database schema changed.
- SQLITE_TOOBIG (int)
- Too much data for one row of a table.
- SQLITE_CONSTRAINT (int)
- Abort due to constraint violation.
- SQLITE_MISMATCH (int)
- Data type mismatch.
- SQLITE_MISUSE (int)
- Library used incorrectly.
- SQLITE_NOLFS (int)
- Uses of OS features not supported on host.
- SQLITE_AUTH (int)
- Authorized failed.
- SQLITE_ROW (int)
- Internal process has another row ready.
- SQLITE_DONE (int)
- Internal process has finished executing.
预定义类
SQLiteDatabase
Represents an opened SQLite database.
构造函数
-
__construct - construct a new SQLiteDatabase object
方法
-
query - Execute a query
-
queryExec - Execute a result-less query
-
arrayQuery - Execute a query and return the result as an array
-
singleQuery - Execute a query and return either an array for one single column or the value of the first row
-
unbufferedQuery - Execute an unbuffered query
-
lastInsertRowid - Returns the rowid of the most recently inserted row
-
changes - Returns the number of rows changed by the most recent statement
-
createAggregate - Register an aggregating UDF for use in SQL statements
-
createFunction - Register a UDF for use in SQL statements
-
busyTimeout - Sets or disables busy timeout duration
-
lastError - Returns the last error code of the most recently encountered error
-
fetchColumnTypes - Return an array of column types from a particular table
SQLiteResult
Represents a buffered SQLite result set.
方法
-
fetch - Fetches the next row from the result set as an array
-
fetchObject - Fetches the next row from the result set as an object
-
fetchSingle - Fetches the first column from the result set as a string
-
fetchAll - Fetches all rows from the result set as an array of arrays
-
column - Fetches a column from the current row of the result set
-
numFields - Returns the number of fields in the result set
-
fieldName - Returns the name of a particular field in the result set
-
current - Fetches the current row from the result set as an array
-
key - Return the current row index
-
next - Seek to the next row number
-
valid - Returns whether more rows are available
-
rewind - Seek to the first row number of the result set
-
prev - Seek to the previous row number of the result set
-
hasPrev - Returns whether or not a previous row is available
-
numRows - Returns the number of rows in the result set
-
seek - Seek to a particular row number
SQLiteUnbuffered
Represents an unbuffered SQLite result set. Unbuffered results sets are sequential, forward-seeking only.
方法
-
fetch - Fetches the next row from the result set as an array
-
fetchObject - Fetches the next row from the result set as an object
-
fetchSingle - Fetches the first column from the result set as a string
-
fetchAll - Fetches all rows from the result set as an array of arrays
-
column - Fetches a column from the current row of the result set
-
numFields - Returns the number of fields in the result set
-
fieldName - Returns the name of a particular field in the result set
-
current - Fetches the current row from the result set as an array
-
next - Seek to the next row number
-
valid - Returns whether more rows are available
运行时配置
这些函数的行为受 php.ini 的影响。
| 名字 | 默认 | 可修改范围 | Changelog |
|---|---|---|---|
| sqlite.assoc_case | "0" | PHP_INI_ALL | Available since PHP 5.0.0. |
以下是配置选项的简要解释。
- sqlite.assoc_case int
-
Whether to use mixed case (0), upper case (1) or lower case (2) hash indexes.
This option is primarily useful when you need compatibility with other database systems, where the names of the columns are always returned as uppercase or lowercase, regardless of the case of the actual field names in the database schema.
The SQLite library returns the column names in their natural case (that matches the case you used in your schema). When sqlite.assoc_case is set to 0 the natural case will be preserved. When it is set to 1 or 2, PHP will apply case folding on the hash keys to upper- or lower-case the keys, respectively.
Use of this option incurs a slight performance penalty, but is MUCH faster than performing the case folding yourself using PHP script.
Table of Contents
- sqlite_array_query — Execute a query against a given database and returns an array
- sqlite_busy_timeout — Set busy timeout duration, or disable busy handlers
- sqlite_changes — Returns the number of rows that were changed by the most recent SQL statement
- sqlite_close — Closes an open SQLite database
- sqlite_column — Fetches a column from the current row of a result set
- sqlite_create_aggregate — Register an aggregating UDF for use in SQL statements
- sqlite_create_function — Registers a "regular" User Defined Function for use in SQL statements
- sqlite_current — Fetches the current row from a result set as an array
- sqlite_error_string — Returns the textual description of an error code
- sqlite_escape_string — Escapes a string for use as a query parameter
- sqlite_exec — Executes a result-less query against a given database
- sqlite_factory — Opens a SQLite database and returns a SQLiteDatabase object
- sqlite_fetch_all — Fetches all rows from a result set as an array of arrays
- sqlite_fetch_array — Fetches the next row from a result set as an array
- sqlite_fetch_column_types — Return an array of column types from a particular table
- sqlite_fetch_object — Fetches the next row from a result set as an object
- sqlite_fetch_single — Fetches the first column of a result set as a string
- sqlite_fetch_string — 别名 sqlite_fetch_single
- sqlite_field_name — Returns the name of a particular field
- sqlite_has_more — Finds whether or not more rows are available
- sqlite_has_prev — Returns whether or not a previous row is available
- sqlite_key — Returns the current row index
- sqlite_last_error — Returns the error code of the last error for a database
- sqlite_last_insert_rowid — Returns the rowid of the most recently inserted row
- sqlite_libencoding — Returns the encoding of the linked SQLite library
- sqlite_libversion — Returns the version of the linked SQLite library
- sqlite_next — Seek to the next row number
- sqlite_num_fields — Returns the number of fields in a result set
- sqlite_num_rows — Returns the number of rows in a buffered result set
- sqlite_open — Opens a SQLite database and create the database if it does not exist
- sqlite_popen — Opens a persistent handle to an SQLite database and create the database if it does not exist
- sqlite_prev — Seek to the previous row number of a result set
- sqlite_query — Executes a query against a given database and returns a result handle
- sqlite_rewind — Seek to the first row number
- sqlite_seek — Seek to a particular row number of a buffered result set
- sqlite_single_query — Executes a query and returns either an array for one single column or the value of the first row
- sqlite_udf_decode_binary — Decode binary data passed as parameters to an UDF
- sqlite_udf_encode_binary — Encode binary data before returning it from an UDF
- sqlite_unbuffered_query — Execute a query that does not prefetch and buffer all data
- sqlite_valid — Returns whether more rows are available
SQLite
23-Jul-2008 07:04
11-Oct-2006 06:19
on win 32
the error "malformed database schema - unable to open a temporary database file for storing temporary tables" may happen if the temp and tmp env vars are typed like this : %WINDIR/Temp
Replace by C:/Windows/Temp and the error will disappear.
02-Jun-2006 12:05
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.
11-May-2006 01:05
The correct url for the windows dll is:
http://pecl4win.php.net/ext.php/php_sqlite.dll
22-Feb-2006 09:15
<$php
public function set_by_db_with_join_to_users_department($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.
12-Nov-2005 01:53
Simple Example for using SQLite for small Buffering Clipboard ;)
<?php
// $Id: SQLiteClipboard.php5,v 1.1 2005/09/09 10:15:26 heinemann Exp $
/**
* @callgraph
* @class SQLiteClipboard
* @short Simple Read/Write Clipboard Class
* @version 0.0.1
* @since Fr Sep 9 08:14:45 CEST 2005
* @code
$sqlite = new SQLiteClipboard( MY_TEMP_DIR );
if ( $sqlite->INSERTING = time() )
var_dump( $sqlite->INSERTING );
else
echo "Nothing done!";
* @endcode
*/
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;
}
} // end Class
?>
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;
}
?>
15-Jul-2005 02:37
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!
30-Jun-2005 08:58
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.
18-Apr-2005 10:30
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
10-Feb-2005 10:03
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
17-Jan-2005 12:42
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");
}
16-Nov-2004 11:24
The same in 3 lines.
<?php
function sqlite_table_exists($db,$mytable) {
/* counts the tables that match the name given */
$result = sqlite_query($db,"SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='$mytable'");
/* casts into integer */
$count = intval(sqlite_fetch_single($result));
/* returns true or false */
return $count > 0;
}
?>
29-Oct-2004 06:41
the OO version.
<?php
function sqlite_table_exists($db,$mytable) {
// ask the database kindly what tables is has.
$result = $db->query("SELECT name FROM sqlite_master WHERE type='table'");
$tables = $result->fetchAll();
// if there's no items in the array then our taget is not going to exists.
if (count($tables) == 0) {
return FALSE ;
}
// loop over the tables to see if there's a table we're looking for.
foreach ($tables as $table) {
if ($table['name'] == $mytable) {
return(TRUE);
}
}
// there was no such table, informe the user the bad news.
return(FALSE);
}
?>
22-Oct-2004 09:26
If you need to check if a table exists, you can use a function like this:
<?php
//Returns TRUE if table exists and FALSE otherwise
// $mytable = table you want to check for
function sqlite_table_exists($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.
19-Oct-2004 06:18
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 isn't auto increment. You have to declare it like this:
id integer primary key
10-Sep-2004 02:39
I've written a short article about the (lack of) use of SQLite in-memory databases: http://www.filipdewaard.com/21_SQLite_inmemory_databases.html . Hopefully it will help somebody out there ;)
09-Aug-2004 05:59
21-Jul-2004 05:50
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
15-Jul-2004 09:29
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.
PHP5 compile time option --enable-sqlite-utf8
See the note about buggy utf-8 support http://uk.php.net/manual/en/function.sqlite-libencoding.php
14-Apr-2004 11:16
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
01-Apr-2004 01:30
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.
14-Feb-2004 10:22
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.
Since this extension is rather new and few tutorials/articles talk about it... here's one worthy of a link:
http://www.php-mag.net/itr/online_artikel/psecom,id,447,nodeid,114
01-Dec-2003 12:53
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)
22-Nov-2003 10:47
If you gone in trouble while/with installation of sqlite,
you can try the installation steps I've 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"
07-Nov-2003 11:19
Very nice MS PowerPoint presentation titled "SQLite and PHP" (author: Wez Furlong) can be downloaded at http://www.php.net/~wez/SQLite_and_PHP.ppt [134 KB]
HTH,
R. Rajesh Jeba Anbiah
