How can I use a variable in a mysql query? [duplicate]

Question

This is my function:

  public function findByIdJoinedToCategory($id)
     {
         $query = $this->getEntityManager()
             ->createQuery(
                 'SELECT a, b
                 FROM App\Entity\Products a
                 JOIN a.productgroup b
                 WHERE a.id = 2');
     }

I simply try to replace 2 with the variable $id. But I do not succeed:

  public function findByIdJoinedToCategory($id)
     {
         $query = $this->getEntityManager()
             ->createQuery(
                 'SELECT a, b
                 FROM App\Entity\Products a
                 JOIN a.productgroup b
                 WHERE a.id = $id');
     }

I get the error message:

[Syntax Error] line 0, col 125: Error: Expected Literal, got '$'

Jim Wright · Accepted Answer · 2019-01-09 15:19:30Z

5

In short, when placing special characters such as a new line or vars in a string you need to use double quotes.

To place a var in a string you need to concatenate it into the string as follows:

'SELECT a, b
FROM App\Entity\Products a
JOIN a.productgroup b
WHERE a.id = '.$id

You are able to able to place the var inside of the string as follows:

"SELECT a, b
FROM App\Entity\Products a
JOIN a.productgroup b
WHERE a.id = $id"

However, you may find the following more readable:

"SELECT a, b
FROM App\Entity\Products a
JOIN a.productgroup b
WHERE a.id = {$id}"

answered Jan 9, 2019 at 15:19

Jim Wright

6,0781 gold badge18 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

peace_love Over a year ago

I think it is working. I get the error now Notice: Array to string conversion but I think this is another issue

Jim Wright Over a year ago

Yes that means $id is an array.

Ray Coder · Accepted Answer · 2019-01-09 15:22:50Z

1

it has to concat the string i think. try this :

public function findByIdJoinedToCategory($id)
     {
         $query = $this->getEntityManager()
             ->createQuery(
                 "SELECT a, b
                 FROM App\Entity\Products a
                 JOIN a.productgroup b
                 WHERE a.id ='$id'");
     }

edited Jan 9, 2019 at 15:22

answered Jan 9, 2019 at 15:17

Ray Coder

1,1114 gold badges15 silver badges36 bronze badges

2 Comments

Ray Coder Over a year ago

try this, i hope it works

Ray Coder Over a year ago

stackoverflow.com/questions/42188422/… try read this thread, hope it can solve

Collectives™ on Stack Overflow

How can I use a variable in a mysql query? [duplicate]

2 Answers 2

2 Comments

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Linked

Related