Writing to database using foreach - php

Question

I have Three arrays and i want to write them to database , The issue I face is whenever the values are written to the particular column the rest of the column is left empty.
The
$name_array = array(3) { [0]"Name1" [1]=>"Name2" [2]=> "Name3" }
$roll_array = array(3) { [0]=>"1" [1]=>"2" [2]=>"3" }
$att_array = array(3) { [0]=>"Present" [1]=>"Present" [2]=>"absent" }
I have three columns in DB "NAME" "ROLL" "ATTENDANCE"
I want to store all the array data to the database at the same time.
so it should look like this
NAME ROLL ATTENDANCE
Name1 1 present
Name2 2 present
Name3 3 absent
Here is the code i tried but it just add each values to the column and leaves the other column empty. So the first three rows has only ROLLNO and next three row has only NAME and last three rows has only ATTENDANCE.
$name_values = array();
$roll_values = array();
$att_values = array();
foreach ($name_array as $key => $name_values) {
$name_values = mysqli_real_escape_string($connection,$name_values);
$sql= "INSERT INTO `aclass12` (Name) VALUES ('$name_values')";
mysqli_query($connection,$sql);
}
foreach ($roll_array as $key => $roll_values) {
$roll_values = mysqli_real_escape_string($connection,$roll_values);
$sql= "INSERT INTO `aclass12` (RollNo) VALUES ('$roll_values')";
}
foreach ($att_array as $key => $att_values) {
$att_values = mysqli_real_escape_string($connection,$att_values);
$sql= "INSERT INTO `aclass12` (attendance) VALUES ('$att_values')";
}
I know this is not the right way to do . and whats the way to do this ?

Answer 1

Simply use one array as the master, and the key of that array to access the other 2 arrays data.
Then insert all the data in a single INSERT
Its also a good idea to check that the INSERT actually worked, so I added a little bit of error checking
foreach ($name_array as $key => $value) {
$name = mysqli_real_escape_string($connection,$value);
$roll = mysqli_real_escape_string($connection,$roll_values[$key]);
$att = mysqli_real_escape_string($connection,$att_array[$key]);
$sql = "INSERT INTO `aclass12`
(Name, RollNo, attendance)
VALUES ('$value', '$roll', '$att')";
$res = mysqli_query($connection,$sql);
if ( $res === FALSE ) {
echo mysqli_error();
exit;
}
}

Answer 2

Use only one foreach and access the elements of the arrays there. Like this:
foreach ($name_array as $key => $name_values) {
$name_values = mysqli_real_escape_string($connection,$name_values);
$roll_values = mysqli_real_escape_string($connection,$roll_array[$key]);
$att_values = mysqli_real_escape_string($connection,$att_array[$key]);
$sql= "INSERT INTO `aclass12` (Name, RollNo, attendance) VALUES ('$name_values', '$roll_values', '$att_values')";
mysqli_query($connection,$sql);
}
Also, it's recommended to use prepared statements, because they prevent SQL njection attacks. More information here.

Answer 3

Try it this ways
for($i = 0; $i < count($name_array);$i++) {
$name_values = mysqli_real_escape_string($connection,$name_array[$i]);
$roll_values = mysqli_real_escape_string($connection,$roll_array[$i]);
$att_values = mysqli_real_escape_string($connection,$att_array[$i]);
$sql= "INSERT INTO `aclass12` (Name, RollNo, attendance) VALUES ('$name_values', '$roll_values','$att_values')";
}
Other option is to use multidimensional array with foreach.

Answer 4

foreach($name_array as $n_k=>$name) {
$roll = (isset($roll_array[$n_k])) ? $roll_array[$n_k] : '';
$att = (isset($att_array[$n_k])) ? $att_array[$n_k] : '';
$name = mysqli_real_escape_string($connection,$name);
$roll = mysqli_real_escape_string($connection,$roll);
$att = mysqli_real_escape_string($connection,$att);
$sql= "INSERT INTO `aclass12` (Name, RollNo, attendance) VALUES ('$name','$roll','$att')";
mysqli_query($connection,$sql);
}

Answer 5

I do think it would be best to use since mysql query to inject it and simply concatenate everything before that. That's something like this:
$query = "INSERT INTO tbl_name (col1, col2, col3) VALUES ";
for ($i = 0; $i < count($name_array); $i++) {
$name = mysqli_real_escape_string($conn, $name_array[$i]);
$roll = mysqli_real_escape_string($conn, $roll_array[$i]);
$att = mysqli_real_escape_string($conn, $att_array[$i]);
$query .= "('{$name}', '{$roll}', '{$att}'),";
}
$query = trim($query, ',');
$query = $query . ';';
mysqli_query($connection,$sql);
Add some damage control there (check for errors) and that's it.