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 — 結果セットの最初のカラムを文字列として取得する
説明
sqlite_fetch_single
( resource
$result
[, bool $decode_binary = TRUE
] ) : stringオブジェクト指向型 (メソッド):
SQLiteResult::fetchSingle
([ bool
$decode_binary = TRUE
] ) : string
SQLiteUnbuffered::fetchSingle
([ bool
$decode_binary = TRUE
] ) : stringsqlite_fetch_single() は、 レコードセットの最初のカラムの値を返すことを除いて sqlite_fetch_array() と等価です。
この関数は、データの単一カラムの値を確認するだけの場合に データを処理する最善の方法です。
パラメータ
-
result -
SQLite 結果リソース。 このパラメータは、 オブジェクト指向言語型メソッドを使用する場合は不要です。
-
decode_binary -
decode_binaryパラメータがTRUE(デフォルト)に 設定された場合、PHP はバイナリエンコーディングをデコードします。 これは、sqlite_escape_string() によりエンコードされたデータに 適用されます。sqlite をサポートする他のアプリケーションにより 作成されたデータベースを処理する時以外は、この値をデフォルトのままにしておくべきです。
返り値
最初のカラムの値を文字列で返します。
例
例1 sqlite_fetch_single() の例
<?php
if ($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 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...*/
}
?>
