Postgresql INSERT INTO使用PHP无法正常工作

Question

What is wrong here? I get the table usertable fine. I've made sure that the column name uid is there. But when I try to get uids from a query, nothing comes back. That is fine as the table is empty. However, my INSERT INTO command is not working because after the INSERT INTO, I still don't have uids coming back. Using Postgres 9.1.5. Thanks!

$query = "SELECT * FROM information_schema.tables WHERE table_name = 'usertable';";
$result = pg_query($dbconn, $query);

if (pg_num_rows($result)) 
{
    echo "Table exists<br>";
    checkForUserRow();
}
else
{
   echo "Error on query, attempting to create table<br>";
   $sql = "CREATE TABLE usertable (uid integer PRIMARY KEY, sign varchar(255));";
   pg_query($dbconn, $sql) or die(pg_errormessage());

   $result = pg_query($dbconn,$query);
   if (pg_num_rows($result)) {
       echo "Table created<br>";
       checkForUserRow();
   }
}

pg_close($conn);

function checkForUserRow()
{
    $query = "SELECT uid FROM usertable WHERE uid = '123'";
    $result = pg_query($dbconn, $query);

if(pg_num_rows($result)) 
{
    echo "User DB row exists<br>";
}
else
{
    echo "User row does not exist - attempt to add user to table<br/>";

    $sql = "INSERT INTO usertable (uid) VALUES('123')";
    pg_query($dbconn, $sql);

    $result = pg_query($dbconn, $query);
    if (pg_num_rows($result)) 
    {
        echo "User successfully added!<br/>";
        }
    else
    {
        echo "User not added :(";
    }
}

Answer 1

Inside your function, you need to get the global $dbconn:

function checkForUserRow()
{
    global $dbconn;
    // everything else
}

This is because when you do pg_query($dbconn, $query); inside of the function, it's using the local version of $dbconn, which doesn't exist.

You can also choose to pass in $dbconn as a parameter if you wish:

function checkForUserRow($dbconn)
{
    // global $dbconn; // Don't need this anymore.
    // everything else
}