Detailed explanation of usage examples of bind_param() function in php

This article mainly introduces the usage of bind_param() function in php, and briefly analyzes the functions, parameters, usage methods and related precautions of bind_param() function, which are required Friends can refer to The example in this article describes the usage of bind_param() function in php. I share it with you for your reference. The details are as follows:

It is not difficult to understand literally, the bound parameters; let me talk about it through an example of bound parameters:

for example:

bind_param("sss", firstname,lastname, $email);

1. This function binds SQL parameters and tells The value of the database parameter. The "sss" parameter column handles the

data type

of the remaining parameters. The s character tells the database that the parameter is a string.

Parameters have the following four types:

i -

integer (integer type) d - double (double precision Float type
)s - string (string) b - BLOB (Boolean value)

Required for each parameter Specify the type. By telling the database the data type of the parameter, you can reduce the risk of SQL injection.

2. The above firstname, lastname, $email are passed by references, which cannot be directly written as strings after PHP5.3. In order to verify this conclusion, I wrote a test here, as follows:

$servername="localhost";
$username="root";
$password="admin";
$dbname="test";
$conn=new mysqli($servername,$username,$password,$dbname);
if($conn->connect_error){
 die("connected failed:".$conn->connect_error);
}
$sql="INSERT INTO user(user_first,user_last,age)VALUES(?,?,?)";
$stmt=$conn->prepare($sql);
$stmt->bind_param("sss","xiao","hong",22);
$stmt->execute();
echo "News records created successfully!";
$stmt->close();
$conn->close();

Above I wrote a test program that writes the parameters directly into strings. After running, it pops up:

Finally, I rewrote the program as follows:

$servername="localhost";
$username="root";
$password="password";
$dbname="test";
$conn=new mysqli($servername,$username,$password,$dbname);
if($conn->connect_error){
   die("Connect failed:".$conn->connect_error);
}
$sql="INSERT INTO user(user_first,user_last,age)VALUES(?,?,?)";
$stmt=$conn->prepare($sql);
$stmt->bind_param("sss",$user_first,$user_last,$age);
$user_first="xiao";
$user_last="hong";
$age=12;
$stmt->execute();
echo "News records created successfully!";
$stmt->close();
$conn->close();

The above program can be executed normally.

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