Why a conn to a mySQL db and a query doesn't work?

Question

I really don't know why I try to connect and extract some data from a MySQL db and it doesn't work. I have a db named "my_db" and a column named "men"; here's my code

$servername = "localhost";
$username = "myusername";
$password = "";
$db = "my_db";

$conn = new mysqli($servername, $username, $password, $db);

$sql="SELECT * FROM men where 'surname' = Smith";
$result = $conn->query($sql);

Where am I going wrong?

`'surname'` should be in backticks (`\``) or no quotes at all, not single quotes. — Nick, Feb 19 '19 at 12:52

score 0 · Answer 1 · answered Feb 19 '19 at 12:55

0

Please try below code:

$servername = "localhost";
$username = "myusername";
$password = "";
$db = "my_db";

$conn = new mysqli($servername, $username, $password, $db);

$sql="SELECT * FROM men where surname = 'Smith'";
$result = $conn->query($sql);

answered Feb 19 '19 at 12:55

abhijeet.supekar

179
6

I am not sure it works since I don't see the number of rows extracted, how can I do? $row = $result->fetch_assoc(); echo $row; but the result is "Array" – Lorenzo Tosone Feb 19 '19 at 13:00
You can check it using $result->num_rows which returns number of rows extracted. And if you want to fetch actual data then you can use $row = $result->fetch_assoc(); print_r($row); – abhijeet.supekar Feb 19 '19 at 13:03
result of "$row = $result->fetch_assoc(); echo $row;" is 'Array' – Lorenzo Tosone Feb 19 '19 at 13:08
Yes it will return Array which you have to travers like this while($row = $result->fetch_assoc()) { echo $row["surname"]; } – abhijeet.supekar Feb 19 '19 at 13:13
and how can I know how many rows that array has got ? – Lorenzo Tosone Feb 19 '19 at 13:18
Use $result->num_rows; to check how many rows that array has got. – abhijeet.supekar Feb 19 '19 at 13:20
Fatal error: Call to undefined method mysqli_result::num_rows() – Lorenzo Tosone Feb 19 '19 at 13:27
Why are you using mysqli_result::num_rows()? I already suggested you to use $result->num_rows; – abhijeet.supekar Feb 19 '19 at 13:30
For more details and different ways to connect mysql database you can refer this: https://www.w3schools.com/php/php_mysql_select.asp – abhijeet.supekar Feb 19 '19 at 13:32
@LorenzoTosone If my answer helped you then, Can you mark my answer as accepted? – abhijeet.supekar Feb 19 '19 at 14:02
it didn't, I am sorry – Lorenzo Tosone Feb 20 '19 at 09:54

Why a conn to a mySQL db and a query doesn't work?

1 Answers1