sqlite_fetch_object
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, PECL sqlite:1.0.1-1.0.3)
sqlite_fetch_single -- SQLiteResult->fetchSingle -- SQLiteUnbuffered->fetchSingle — Fetches the first column of a result set as a string
Opis
string sqlite_fetch_single
( resource $result
[, bool $decode_binary
] )
Object oriented style (method):
SQLiteResult
string fetchSingle
([ bool $decode_binary
] )
SQLiteUnbuffered
string fetchSingle
([ bool $decode_binary
] )
sqlite_fetch_single() is identical to sqlite_fetch_array() except that it returns the value of the first column of the rowset.
This is the most optimal way to retrieve data when you are only interested in the values from a single column of data.
Parametry
- result
-
The SQLite result resource. This parameter is not required when using the object-oriented method.
- decode_binary
-
Kiedy parametr decode_binary zostanie ustawiony na TRUE (domyślnie), PHP zdekoduje kodowanie binarne, któremu zostały poddane dane, jeśli były kodowane przy użyciu funkcji sqlite_escape_string(). Zazwyczaj należy pozostawić domyślną wartość tego parametru, chyba że baza jest współużytkowana przez różne aplikacje.
Przykłady
Example #1 A sqlite_fetch_single() example
<?php
if ($dbhandle = sqlite_open('mysqlitedb', 0666, $sqliteerror)) {
$sql = "SELECT id FROM sometable WHERE id = 42";
$res = sqlite_query($dbhandle, $sql);
if (sqlite_num_rows($res) > 0) {
echo sqlite_fetch_single($res); // 42
}
sqlite_close($dbhandle);
}
?>
add a note
User Contributed Notessqlite_fetch_single
jmarbas at hotmail dot com
24-Jul-2005 02:45
24-Jul-2005 02:45
roga at yoopee dot de
11-Jul-2004 10:02
11-Jul-2004 10:02
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...*/
}
?>