Introduction to the usage of php bind_param() function

This article mainly introduces the usage of bind_param() function in php. It briefly analyzes the functions, parameters, usage and related precautions of bind_param() function. , required Friends can refer to

The examples in this article describe the usage of bind_param() function in php. Share it with everyone for your reference, the details are as follows:

It is not difficult to understand literally, the binding parameters; let me explain it through an example of binding 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 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();

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