MySQL to create new row in two tables with the Primary ROWS ID

Question

I have two tables: Incidents and Investigations

Incidents is my primary table and when I open a new case most of the information is inserted here. What I need is in the Investigations table to insert some of the information from the primary table. Both tables have id as they Primary Key and both ID's has auto increment. I am not much concerned about the ID in Investigations as this is not used much.

What I am trying to do is once the Incidents row is created it should take the id (Primary Key) and insert it automatically into Investigations table under column case_id and some of the other info I pass thru.

Will I be able to do this using PHP insert?

Current Code:

$sql = "INSERT INTO stinghs.incident SET
                date = '".$date."',
                time = '".$time."',
                corrective = '".$corrective."',
                status = 'Open'";

if ($conn->query($sql) === TRUE) {
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
    echo("Error description: " . mysqli_error($con));
    echo "Error 1";
}

$sql1 = "INSERT INTO stinghs.investigation SET
                date = '".$date."',
                time = '".$time."',
                case_id = '".$case_id."',
                status = 'Open'";

if ($conn->query($sql1) === TRUE) {
} else {
    echo "Error: " . $sql1 . "<br>" . $conn->error;
    echo("Error description: " . mysqli_error($con));
    echo "Error 1";
}

I am battling as this runs one after each other and there is no ID yet assigned or drawn as case_id?

UPDATE AND CORRECT CODE:

$sql = "INSERT INTO stinghs.incident SET
                date = '".$date."',
                time = '".$time."',
                corrective = '".$corrective."',
                status = 'Open'";

if ($conn->query($sql) === TRUE) {
    $last_id = mysqli_insert_id($conn); //Retrieve the last ID of the record
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
    echo("Error description: " . mysqli_error($con));
    echo "Error 1";
}

$sql1 = "INSERT INTO stinghs.investigation SET
                date = '".$date."',
                time = '".$time."',
                case_id = '".$last_id."',
                status = 'Open'";

if ($conn->query($sql1) === TRUE) {
} else {
    echo "Error: " . $sql1 . "<br>" . $conn->error;
    echo("Error description: " . mysqli_error($con));
    echo "Error 1";
}

Answer 1

$case_id would be the mysql last insert id on your connection object. https://www.php.net/manual/en/function.mysql-insert-id.php