php 在PHP中使用SQlite3如何计算结果集中的行数？
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Using SQlite3 in PHP how to count the number of rows in a result set?
提问by Remover
currently I am using:
目前我正在使用：
$result = new SQLite3(sprintf("users/USERIDS_DB.sqlite"));
$numRows = $result->exec ("SELECT count(*) FROM USERIDS");
echo sprintf("the number of rows are: %d", $numRows);
but the result is 1 when it should be 6 (the number of rows I created using firefox sqlite3 addon)
但结果是 1，而它应该是 6（我使用 firefox sqlite3 插件创建的行数）
Can anybody help please?
有人可以帮忙吗？
回答by RoboTamer
$db = new SQLite3('filename.db3');
$count = $db->querySingle("SELECT COUNT(*) as count FROM tablename");
echo $count;
回答by Felix Kling
From the documentation:
从文档：
public bool SQLite3::exec ( string $query )
Executes a result-lessquery against a given database.
public bool SQLite3::exec ( string $query )
对给定的数据库执行无结果查询。
This methods returns a boolean, not a result set. When you convert trueto an integer it will become 1.
此方法返回一个布尔值，而不是结果集。当您转换true为整数时，它将变为1.
You should use SQLite3::query(). Example (untested):
你应该使用SQLite3::query(). 示例（未经测试）：
$rows = $result->query("SELECT COUNT(*) as count FROM USERIDS");
$row = $rows->fetchArray();
$numRows = $row['count'];
Btw, naming the instance of the SQLite3 class $resultcan be misleading (especially in a DB environment). I would call it $dbor $connection.
顺便说一句，命名 SQLite3 类的实例$result可能会产生误导（尤其是在数据库环境中）。我会称它为$db或$connection。
回答by fordiy
$result = $db->query("SELECT * FROM db_name")
$row=$result->fetchArray(SQLITE3_ASSOC);
// check for empty result
if ($row != false) {
// do something here if record exists
}
回答by Simbarashe D Andrea
<?php
function SqliteNumRows($query){
$numRows = 0;
while($rows = $query->fetchArray()){
++$numRows;
}
return $numRows;
}
?>
This really helped me it works actually you may try it
这真的对我有帮助，实际上你可以试试
回答by russell
Here is a working way to get the number of rows since neither sqlite_num_rows($result)nor $result->numRows()works on SQLite3:
这里是工作的方式来获得，因为没有行数sqlite_num_rows($result)，也不$result->numRows()适用于SQLite3的：
<?php
$db = new SQLite3('database.db');
$results = $db->query('SELECT COUNT(*) FROM (SELECT `id`,* FROM `table` ORDER BY `id` ASC);');
while ($row = $results->fetchArray()) {
echo $row["COUNT(*)"];
}
?>
回答by Nabi K.A.Z.
It's have benefit, when you have conditions in the count selectquery:
当您在计数select查询中有条件时，它有好处：
$stmt = $db->prepare('SELECT COUNT(*) AS `count` FROM `tablename` WHERE `foo`=:foo');
$stmt->bindValue(':foo', $foo);
$stmt->execute();
$count = $stmt->fetchColumn();
echo $count;
