我只是想查询两个不同的表,看看是否有一个匹配。我已经做了很多关于如何做到这一点的研究,我一直看到的是使用联接子句。但我不想在两张桌子之间找到一个匹配的。我只需要查询两个表,看看是否有一行匹配。
这是我正在使用的代码。
$query = " SELECT id,account_type,email, password FROM client
WHERE email = ?
UNION
SELECT id,account_type,email, password FROM freelancers
WHERE email = ? ";
$email = $this->input->post("email");
$result = $this->db->query($query, [$email]);
// Just check if first there is an email that exists the database
if($result -> num_rows() == 1) {
//Do something
}
您可以尝试使用子查询:
$query = "SELECT * FROM client WHERE email = (SELECT email FROM freelancers WHERE email = ?)";
$email = $this->input->post("email");
$result = $this->db->query($query, array($email));