PHP mysqli_stmt_param_count()用法及代码示例

定义和用法

这个mysqli_stmt_param_count()函数接受一个(准备好的)语句对象作为参数并返回其中的参数标记数。

用法

mysqli_stmt_param_count($stmt)

参数

Sr.No	参数及说明
1	stmt(Mandatory) 这是一个对象，表示执行 SQL 查询的语句。

返回值

PHP mysqli_stmt_param_count() 函数返回一个整数值，指示给定准备语句中参数标记的数量。

PHP版本

这个函数最初是在 PHP 版本 5 中引入的，适用于所有后续版本。

示例

假设我们在 MySQL 数据库中创建了一个名为employee 的表，内容如下：

mysql> select * from employee;
+------------+--------------+------+------+--------+
| FIRST_NAME | LAST_NAME    | AGE  | SEX  | INCOME |
+------------+--------------+------+------+--------+
| Vinay      | Bhattacharya |   20 | M    |  21000 |
| Sharukh    | Sheik        |   25 | M    |  23300 |
| Trupthi    | Mishra       |   24 | F    |  51000 |
| Sheldon    | Cooper       |   25 | M    |   2256 |
| Sarmista   | Sharma       |   28 | F    |  15000 |
+------------+--------------+------+------+--------+
5 rows in set (0.00 sec)

以下示例演示了 mysqli_stmt_param_count() 函数的用法(程序风格) -

<?php
   $con = mysqli_connect("localhost", "root", "password", "mydb");

   $stmt = mysqli_prepare($con, "UPDATE employee set INCOME=INCOME-? where INCOME>=?");
   mysqli_stmt_bind_param($stmt, "si", $reduct, $limit);
   $limit = 20000;
   $reduct = 5000;

   //Executing the statement
   mysqli_stmt_execute($stmt);
   print("Records Updated......\n");

   //Affected rows
   $count = mysqli_stmt_param_count($stmt);

   //Closing the statement
   mysqli_stmt_close($stmt);

   //Closing the connection
   mysqli_close($con);

   print("Rows affected ".$count);
?>

这将产生以下结果 -

Records Updated......
Rows affected 3

示例

在面向对象风格中，这个函数的语法是 $stmt->param_count;以下是面向对象样式 $minus 中此函数的示例；

<?php
   //Creating a connection
   $con = new mysqli("localhost", "root", "password", "mydb");

   $con -> query("CREATE TABLE myplayers(ID INT, First_Name VARCHAR(255), Last_Name VARCHAR(255), Place_Of_Birth VARCHAR(255), Country VARCHAR(255))");
   print("Table Created.....\n");

   $stmt = $con -> prepare( "INSERT INTO myplayers values(?, ?, ?, ?, ?)");
   $stmt -> bind_param("issss", $id, $fname, $lname, $pob, $country);
   $id = 1;
   $fname = 'Shikhar';
   $lname = 'Dhawan';
   $pob = 'Delhi';
   $country = 'India';

   //Executing the statement
   $stmt->execute();

   //Affected rows
   $count = $stmt ->param_count;
   print("Number of parameters:".$count);

   //Closing the statement
   $stmt->close();

   //Closing the connection
   $con->close();
?>

这将产生以下结果 -

Table Created.....
Records Deleted.....
Number of parameters:5