It isnt specified in the above description for this function, but yes this function will not only return the first column, but it will also return the first value (ie from the first row in the result set) of that column. Also the result set pointer is involved here in that if you use sqlite_fetch_single in a loop, it will return each value in the first column sequentially and advance the result set pointer each time.
i.e. the first loop iteration it returns the first value in the first column. the second loop iteration it returns the second value in the first column. the third loop iteration the third value and so on.
$handle = sqlite_open("database_file_name") or die("Could not open database");
//generate query string
$query = "select distinct field1 from database_name";
//execute query
$result = sqlite_query($handle,$query)
//if a row exists
if(sqlite_num_rows($result)>0){
echo "<table cellpadding=\"10\" border=\"1\">";
//check for more rows
while(sqlite_has_more($result)){
//get first field from each row
//print values
$row=sqlite_fetch_single($result);
echo "<tr>";
echo "<td>".$row."</td>";
echo "</tr>";
}
echo "</table>";
}
//close database file
sqlite_close($handle);
sqlite_fetch_single
SQLiteResult::fetchSingle
SQLiteUnbuffered::fetchSingle
(PHP 5 < 5.4.0, PECL sqlite >= 1.0.1)
sqlite_fetch_single -- SQLiteResult::fetchSingle -- SQLiteUnbuffered::fetchSingle — Lit la première ligne d'un résultat SQLite sous forme de chaîne
Description
sqlite_fetch_single
( resource
$result
[, bool $decode_binary = TRUE
] ) : stringStyle orienté objet (method):
SQLiteResult::fetchSingle
([ bool
$decode_binary = TRUE
] ) : string
SQLiteUnbuffered::fetchSingle
([ bool
$decode_binary = TRUE
] ) : stringsqlite_fetch_single() est identique à sqlite_fetch_array() hormis le fait qu'elle retourne uniquement la valeur de la première colonne du résultat.
C'est la méthode optimale pour lire des données, si vous n'êtes intéressé que par les valeurs de la première colonne.
Liste de paramètres
-
result -
La ressource de résultat SQLite. Ce paramètre n'est pas requis lorsque vous utilisez la méthode orientée objet.
-
decode_binary -
Lorsque
decode_binaryvautTRUE(par défaut), PHP va décoder les données binaires, si elles ont été codées avec la fonction sqlite_escape_string(). Vous allez généralement laisser cette valeur à sa valeur par défaut, à moins que vous ne travailliez avec des bases opérées par d'autres applications.
Valeurs de retour
Retourne la valeur de la première colonne, sous la forme d'une chaîne de caractères.
Exemples
Exemple #1 Exemple avec sqlite_fetch_single()
<?php
if ($db = sqlite_open('mysqlitedb', 0666, $sqliteerror)) {
$sql = 'SELECT id FROM sometable WHERE id = 42';
$res = sqlite_query($db, $sql);
if (sqlite_num_rows($res) > 0) {
echo sqlite_fetch_single($res); // 42
}
sqlite_close($db);
}
?>
add a note
User Contributed Notes 3 notes
jmarbas at hotmail dot com ¶
19 years ago
visavi dot net at mail dot ru (Vantuz) ¶
15 years ago
With the help of sqlite_fetch_single, you can quickly and easily calculate the number of elements in the table
<?php
// create new database (OO interface)
$db = new SQLiteDatabase('database.db', 0666);
// create table inbox and paste data
$db->queryExec("
CREATE TABLE inbox (
inbox_id INTEGER NOT NULL PRIMARY KEY,
inbox_send varchar(20) NOT NULL,
inbox_text TEXT NOT NULL,
inbox_time INTEGER UNSIGNED NOT NULL,
inbox_user varchar(20) NOT NULL
);");
$ins_query = "
INSERT INTO inbox (inbox_send, inbox_text, inbox_time, inbox_user) VALUES ('Ilia1', 'Message1', '".time()."', 'my_name');
INSERT INTO inbox (inbox_send, inbox_text, inbox_time, inbox_user) VALUES ('Ilia2', 'Message2', '".time()."', 'user');
INSERT INTO inbox (inbox_send, inbox_text, inbox_time, inbox_user) VALUES ('Ilia2', 'Message3', '".time()."', 'my_name');
";
$db->queryExec($ins_query);
//view all posts by my_name
$total = $db->singleQuery("SELECT count(*) FROM inbox WHERE inbox_user='my_name';");
echo $total;
// the result will be the number 2
/* P.S. sorry for my english */
?>
roga at yoopee dot de ¶
20 years ago
Be careful with the use of sqlite_fetch_single() in a while-loop:
<?php
$result = sqlite_query($db_handle, 'SELECT foo FROM bar;');
while ($row = sqlite_fetch_single($result)) {
/*...do s.th. with $row...*/
}
?>
This may not work as expected because the loop will stop if any of the foos has a false value (e.g. zero).
Use sqlite_has_more() instead:
<?php
$result = sqlite_query($db_handle, 'SELECT foo FROM bar;');
while (sqlite_has_more($result)) {
$row = sqlite_fetch_single($result);
/*...do s.th. with $row...*/
}
?>
