have to bind array param everytime in loop with php mysqli - php

Question

I have a loop in which I have to do multiple inserts to the database, it appears that I have to bind the data array every time I get new data and the data changes. I though we could bind once and insert multiple times.
Further research has shown that PDO might be better suited to this task, but I'm curious why its like this with mysqli, and if there is a way to bind array once and execute multiple times.
See comments in code for more detail.
<?php
//usual db stuff
$DBhost = 'localhost';
$DBname = 'test';
$DBuser = '';
$DBpass = '';
//error reporting for mysql
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
//connect to database
$conn = new mysqli($DBhost, $DBuser, $DBpass, $DBname);
//prepare this is a dummy table in a dummy database
//actual table is quite complicated
$stmt = $conn->prepare('INSERT INTO `users` (`fname`,`lname`,`city`) VALUES(?,?,?)');
//create a variable to store the data
// so we can bind it before going further
$data=array_fill(0,3,'');
//bind params use array expansion
$stmt->bind_param('sss', ...$data);
//this part runs in a loop
// mock loop for just to show idea
for($i=0;$i<1;$i++)
{
//get the data
$data = get_data();
//already binded $data before the loop
//so execute this should insert the data just returned
//except this doesnt, it inserts blanks
//it acts as if the data still has the blank array from line 20
$stmt->execute();
//bind it again
$stmt->bind_param('sss', ...$data);
//execute
//this inserts the data
$stmt->execute();
}
//mock function to return data the actual function
//returns a multi dimesional array for multiple tables
function get_data()
{
return(array("dinesh","chand","nadi"));
}
any help or ideas highly appreciated

Answer 1

When you run $stmt->execute(); for the first time, inside the for loop, you are executing what you have bind before starting the for loop. So what you have to do is.
Bind what you want $stmt->bind_param('sss', ...$data);
Then execute $stmt->execute();
In your code above, first, remove $stmt->execute(); (first inside the for loop). Then add it after you bind the parameters for the first time(above the for loop). As follows,
Note: What I have changed are marked with ########
<?php
//usual db stuff
$DBhost = 'localhost';
$DBname = 'test';
$DBuser = '';
$DBpass = '';
//error reporting for mysql
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
//connect to database
$conn = new mysqli($DBhost, $DBuser, $DBpass, $DBname);
//prepare this is a dummy table in a dummy database
//actual table is quite complicated
$stmt = $conn->prepare('INSERT INTO `users` (`fname`,`lname`,`city`) VALUES(?,?,?)');
//create a variable to store the data
// so we can bind it before going further
$data=array_fill(0,3,'');
//bind params use array expansion
$stmt->bind_param('sss', ...$data);
$stmt->execute(); //########
//this part runs in a loop
// mock loop for just to show idea
for($i=0;$i<1;$i++)
{
//get the data
$data = get_data();
//already binded $data before the loop
//so execute this should insert the data just returned
//except this doesnt, it inserts blanks
//it acts as if the data still has the blank array from line 20
//$stmt->execute(); ########
//bind it again
$stmt->bind_param('sss', ...$data);
//execute
//this inserts the data
$stmt->execute();
}