MySQL - 计算php中的总行数

Question

在没有应用任何条件的情况下,计算表中总行数的最佳MySQL命令是什么？我是通过php做的,所以也许有一个PHP函数为我做这个？我不知道.这是我的PHP的一个例子:

<?php
$con = mysql_connect("server.com","user","pswd");
if (!$con) {
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("db", $con);

$result = mysql_query("some command");
$row = mysql_fetch_array($result);

mysql_close($con);
?>

Answer 1

<?php
$con = mysql_connect("server.com","user","pswd");
if (!$con) {
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("db", $con);

$result = mysql_query("select count(1) FROM table");
$row = mysql_fetch_array($result);

$total = $row[0];
echo "Total rows: " . $total;

mysql_close($con);
?>

Answer 2

在MySQL查询中使用COUNT或执行SELECT*FROM表并执行:

$result = mysql_query("SELECT * FROM table");
$rows = mysql_num_rows($result);
echo "There are " . $rows . " rows in my table.";

Answer 3

你只能在一行中做到如下:

$cnt = mysql_num_rows(mysql_query("SELECT COUNT(1) FROM TABLE"));
echo $cnt;

Answer 4

COUNT在SELECT查询中使用.

$result = mysql_query('SELECT COUNT(1) FROM table');
$num_rows = mysql_result($result, 0, 0);

Answer 5

mysqli_num_rows 在 php 5 及以上版本中使用。

例如

<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$sql="SELECT Lastname,Age FROM Persons ORDER BY Lastname";

if ($result=mysqli_query($con,$sql))
  {
  // Return the number of rows in result set
  $rowcount=mysqli_num_rows($result);
  printf("Result set has %d rows.\n",$rowcount);
  // Free result set
  mysqli_free_result($result);
  }
mysqli_close($con);
?>