“ where子句”中的未知列“ $ id”

Question

I am using codeigniter, I am displaying all the job vacancies on one page, each individual job post has a button to view more information about the current post. when I try to pass the id variable for the individual post into the query I keep getting the error below.

Unknown column '$id' in 'where clause'

query code

function get_vacancie($id) {

$query = $this->db->query('SELECT vacancies_id,name, vacancie_desc, pay FROM vacancies where vacancies_id=$id');
return $query = $query->row();


}

Answer 1

Your query should look like this:

$query = $this->db->query('SELECT vacancies_id,name, vacancie_desc, pay FROM vacancies WHERE vacancies_id=' . $id);

This should work!

Answer 2

Strings in single quotes doesn't evalute PHP variables. Change single-quotes to double-quotes and it will do the job:

$query = $this->db->query("SELECT vacancies_id,name, vacancie_desc, pay FROM vacancies where vacancies_id=$id");

Answer 3

Your mistake was single quote

function get_vacancie($id) {
$query = $this->db->query("SELECT vacancies_id,name, vacancie_desc, pay FROM vacancies where vacancies_id=$id");
return $query = $query->row();
}

Try this code with double code

Answer 4

您也可以这样做：

$query = $this->db->query("SELECT vacancies_id,name, vacancie_desc, pay FROM vacancies WHERE vacancies_id={$id}");