While循环和PHP / MYSQL插入语句

Question

Am I able or how can I create a while loop to run through some insert statemtns. I have some code below that I have tried to use using i++ but I keep getting errors in relation to where I have put $i such as:

Object of class PDOStatement could not be converted to string

Its hard to explain the previous code that amounts to this insert setup, but basically I decalre some variables and then they get bind and inserted with the following code but I have like 30 thins that could be inserted hence the while loop. So the outcome should be supplier_name2 - supplier_name30 and same for address etc etc.

   while ($i <= 30):
      //LINE TWO
      $suppliername = $this->supplier_name.$i;
      if(!empty($suppliername)){
          $sql0.$i = "INSERT INTO suppliers (supplier_name, supplier_address) 
                          VALUES (:supplier_name.$i, :supplier_address.$i) ";   
          $st0.$i = $conn->prepare ( $sql0.$i );
          $st0.$i->bindValue( ":supplier_name".$i, $this->supplier_name.$i, PDO::PARAM_STR );
          $st0.$i->bindValue( ":supplier_address".$i, $this->supplier_address.$i, PDO::PARAM_STR);
          $st0.$i->execute();
          $this->id = $conn->lastInsertId();
          $supplierid.$i = $this->id = $conn->lastInsertId();
        }  
    $i++; 
    endwhile;

Any help appreciated. Ian

Answer 1

Expression $sql0.$i will be interpreted as string so PHP will try to use your PDOStatement as string. It's not the way you should use prepared statements .

Move your prepared statement before loop with some modifications.

$sql = "INSERT INTO suppliers (supplier_name, supplier_address) 
                      VALUES (:supplier_name, :supplier_address) ";   
$statement = $conn->prepare ( $sql );

Then perform bindValue() and execute() on $statement variable. Idea is to declared once and use few times. Also don't use $i in attributes names, it's unnecessary.

Answer 2

In > "supplier_name.$i" the dot is literal. So it becomes "supplier_name.1", "supplier_name.2" etc

In ":supplier_address".$i the dot is not literal, it is used as the concatenation operator. Hence you get "supplier_name1" and "supplier_name2" etc. Hence no replacement occurs I assume.

Answer 3

Can you try this, below one insert supplier_name1 - supplier_name30 in tables.

          while ($i <= 30):
              //LINE TWO
              $suppliername = $this->supplier_name.$i;
              $supplier_address = $this->supplier_address.$i;
              if(!empty($suppliername)){
                $sql0 = "INSERT INTO suppliers (supplier_name, supplier_address)
                VALUES (:supplier_name, :supplier_address) ";
                $st0 = $conn->prepare ( $sql0 );
                $st0->bindValue( ":supplier_name", $suppliername, PDO::PARAM_STR );
                $st0->bindValue( ":supplier_address", $supplier_address, PDO::PARAM_STR);
                        $st0.$i->execute();
                        $this->id = $conn->lastInsertId();
                $supplierid = $this->id = $conn->lastInsertId();
              }
              $i++;
          endwhile;