sqlite_query
SQLiteDatabase::query
(PHP 5 < 5.4.0, PECL sqlite >= 1.0.0)
sqlite_query -- SQLiteDatabase::query — Executes a query against a given database and returns a result handle
Description
$dbhandle
, string $query
[, int $result_type = SQLITE_BOTH
[, string &$error_msg
]] )$query
, resource $dbhandle
[, int $result_type = SQLITE_BOTH
[, string &$error_msg
]] )Object oriented style (method):
$query
[, int $result_type = SQLITE_BOTH
[, string &$error_msg
]] )
Executes an SQL statement given by the query against
a given database handle.
Parameters
-
dbhandle -
The SQLite Database resource; returned from sqlite_open() when used procedurally. This parameter is not required when using the object-oriented method.
-
query -
The query to be executed.
Data inside the query should be properly escaped.
-
result_type -
The optional
result_typeparameter accepts a constant and determines how the returned array will be indexed. UsingSQLITE_ASSOCwill return only associative indices (named fields) whileSQLITE_NUMwill return only numerical indices (ordinal field numbers).SQLITE_BOTHwill return both associative and numerical indices.SQLITE_BOTHis the default for this function. -
error_msg -
The specified variable will be filled if an error occurs. This is specially important because SQL syntax errors can't be fetched using the sqlite_last_error() function.
Note: Two alternative syntaxes are supported for compatibility with other database extensions (such as MySQL). The preferred form is the first, where the
dbhandleparameter is the first parameter to the function.
Return Values
This function will return a result handle or FALSE on failure.
For queries that return rows, the result handle can then be used with
functions such as sqlite_fetch_array() and
sqlite_seek().
Regardless of the query type, this function will return FALSE if the
query failed.
sqlite_query() returns a buffered, seekable result handle. This is useful for reasonably small queries where you need to be able to randomly access the rows. Buffered result handles will allocate memory to hold the entire result and will not return until it has been fetched. If you only need sequential access to the data, it is recommended that you use the much higher performance sqlite_unbuffered_query() instead.
Changelog
| Version | Description |
|---|---|
| 5.1.0 |
Added the error_msg parameter
|
Notes
SQLite will execute multiple queries separated by semicolons, so you can use it to execute a batch of SQL that you have loaded from a file or have embedded in a script. However, this works only when the result of the function is not used - if it is used, only the first SQL statement would be executed. Function sqlite_exec() will always execute multiple SQL statements.
When executing multiple queries, the return value of this function
will be FALSE if there was an error, but undefined otherwise (it might
be TRUE for success or it might return a result handle).
See Also
- sqlite_unbuffered_query() - Execute a query that does not prefetch and buffer all data
- sqlite_array_query() - Execute a query against a given database and returns an array
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Коментарии
The function below allows you to submit multiple queries in one shot to a SQLITE database, and will return whatever you would get for the final query.
function sqlite_query_multi ($db, $query) {
// submit multiple queries (separated by ;) to $db
// and return the result from the last one
$multiSQL = "/('[^']*'|\"[^\"]*\"|[^;'\"])*;/";
preg_match_all ($multiSQL, "$query;", $aSQL);
for ($i=sizeof($aSQL=$aSQL[0]);$i--;)
if (!($trim=trim(substr($aSQL[$i],0,-1))))
unset ($aSQL[$i]);
else $aSQL[$i] = "$trim;";
foreach ($aSQL as $i => $sql)
$dbRes = sqlite_query ($db, $sql);
return (@$dbRes);
}
The section below illustrates the above function:
$db = sqlite_open(":memory:", 0666, $sqliteerror);
$query = <<<EOD
CREATE TABLE foo (bar INTEGER PRIMARY KEY, baz TEXT);
INSERT INTO foo VALUES (Null, 'Hi');
INSERT INTO foo VALUES (Null, 'Mom');
SELECT * FROM foo;
EOD;
$dbRes = sqlite_query_multi ($db, $query); // 4 statements
while (sqlite_has_more($dbRes))
var_dump(sqlite_fetch_array($dbRes, SQLITE_ASSOC));
Csaba Gabor
While reading the manual at sqlite.org, I can answer for the quotes in strings. You should put two quote to get one.
insert into atable values ( '5 O''Clock');
sqlite_open will return NULL if the web server cannot write to the sqlite database file.
I saw the following message in my web server error log:
PHP Warning: sqlite_query(): (null) ...
It turns out that the sqlite database file was owned by a user other than the one the web server was running as. In my case, it was a Linux system running Apache (which was running under the context of user apache). The sqlite database file was owned by root. I changed ownership of the file to user apache and now it works! The sqlite_open call now returns a valid result handle.
Jason Aeschilman
Correction:
sqlite_query will return NULL if the web server cannot write to the sqlite database file.
(please correct the previous post and delete this one)
I suppose this could be useful for users attempting to use a sqlite database for the first time.<?php
$database = new SQLiteDatabase($yourfile, 0666, $error);
if (!$database) {
$error = (file_exists($yourfile)) ? "Impossible to open, check permissions" : "Impossible to create, check permissions";
die($error);
}
$query = $database->query("SELECT name FROM sqlite_master WHERE type='table'", SQLITE_ASSOC, $query_error); #Lists all tables
if ($query_error)
die("Error: $query_error"); #This means that most probably we catch a syntax error
if (!$query)
die("Impossible to execute query.") #As reported above, this means that the db owner is different from the web server's one, but we did not commit any syntax mistake.
print $query->numRows();
while ($row = $query->fetch())
print($row['name']."\n");
?>
i suppose that the example above is also useful because it will list all the tables created, giving also comprehension of what appens when managing a sqlite database in OO mode.
In follow up to Csaba Gabor's function (see below) that allows for multi-statement queries to be executed via sqlite_query() this alternative implementation avoids a problem with Csaba's version (which prevents multi-statement constructs like CREATE TRIGGER from being parsed correctly).<?php
function sqlite_query_multi ($db, $query) {
//
// sqlite_query() rewritten to support concatenated SQL statements.
//
// This method works around the sqlite_query() deficiency by splitting
// queries into two parts; the first part comprising all the statements
// except the last one (executed via sqlite_exec) and then the last
// statement (executed via sqlite_query).
//
// This allows the result of the last SELECT statement in a multi-statement
// query to be accessed regardless of the SQL statements that came before it.
// It also allows execution of arbitrary multi-statement programs regardless
// whether the result is needed, subject to the following constraint:
//
// This method requires that the last statement in a multi-statement query
// is a valid "stand-alone" SQL statement. If it is not (eg, the "END;" of
// a multi-statement construct such as CREATE TRIGGER) append an additional
// ";" (ie, a NULL statement). Normally this should not be needed because
// almost all the multi-statement constructs I can think of should have a
// stand-alone statement following them (ie, to makes use of the construct).
//
$pattern = '/^(.*;)(.*;)/s';
if ( preg_match($pattern,$query,$match) ) {
// multi-statement query
sqlite_exec($db,$match[1]);
$result = sqlite_query($db,$match[2]);
} else {
// single-statement query
$result = sqlite_query($db,$query);
}
return (@$result);
}
?>
Not a lot of examples on using the oo style of using sqlite files. Maybe this helps someone trying to figure out all the names of the tables inside an sqlite file.
<?php
/* Just extend the class, add our method */
class MySQLiteDatabase extends SQLiteDatabase {
/* A neat way to see which tables are inside a valid sqlite file */
public function getTables() {
$tables=array();
$q = $this->query(sprintf("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name"));
$result = $q->fetchAll();
foreach($result as $tot_table) {
$tables[]=$tot_table['name'];
}
return($tables);
}
}
/* a sqlite file */
$database="BLAHBLAH.sqlite";
if (file_exists($database)) {
$db = new MySQLiteDatabase($database, 0666, $err);
if ($err) {
trigger_error($err);
} else {
print_r($db->getTables());
}
}
/* this sqlite db had 2 tables:
Array
(
[0] => Account
[1] => Device
)
*/
?>