如何从表A获取INT类型的ID并将其插入到另一个表中？ 在PHP中

Question

I am not doing insert query, so the mysqli_insert_id doesnt' work.

I need to select an id(Primary, INT) from Table A which will be inserted into Table B.

My Tables Structure:

Table book:
-id (Primary, Auto Increment, INT)
-title
-publisher_id (Foreign key to Table publisher.pub_id, INT)

Table publisher:
-pub_id (Primary, Auto Increment, INT)
-publisher

I tried like this:

$query ="SELECT pub_id FROM book WHERE publisher = '$publisher' ";
$result=$mysqli->query($query);
$pub_id=$result->fetch_assoc();

$query ="INSERT INTO book (title,publisher_id)
              VALUES ('$title', '$pub_id['pub_id']')";
$mysqli->query($query);

Then I got error message like:

syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE), expecting '-' or identifier (T_STRING) or variable (T_VARIABLE) or number (T_NUM_STRING) 

Is there something wrong with the data type or something else?

How to get INT-type id from Table book and insert it into another table?

Answer 1

It doesn't work because you are doing this:

$query ="INSERT INTO book (title,publisher_id)
              VALUES ('$title', '$pub_id['pub_id']')";

Try this instead:

$query ="INSERT INTO book (title,publisher_id)
              VALUES ('$title', '".$pub_id['pub_id']."')";