How do I check if PHP is connected to a database already

Question

Basically in pseudo code I m looking for something like  if  connected to any database             do nothing   else       mysql connect          How do I implement  connected to any database

User · Answer

Earlier in your code mysql connect    set a flag that db is connected        Later     if  flag is set     mysql connect

User · Answer

mysql ping

User · Answer

Have you tried mysql ping    Update  From PHP 5 5 onwards  use mysqli ping   instead   Pings a server connection  or tries to reconnect if the connection has gone down  if   mysqli- gt ping        printf   quot Our connection is ok  n quot       else     printf   quot Error   s n quot    mysqli- gt error        Alternatively  a second  less reliable  approach would be   link   mysql connect  localhost   username   password            if  link    false         try to reconnect

User · Answer

Baron Schwartz blogs that due to race conditions  this  check before write  is a bad practice   He advocates a try catch pattern with a reconnect in the catch   Here is the pseudo code he recommends   function query database connection  sql  retries 1     while true       try          result connection execute sql           return result       catch InactiveConnectionException e          if retries  gt  0 then             retries   retries - 1             connection reconnect            else             throw e          end       end    end end   Here is his full blog  https   www percona com blog 2010 05 05 checking-for-a-live-database-connection-considered-harmful

User · Answer

before     I mean somewhere in some other file you re not sure you ve included    db   mysql connect     later     if  is resource  db        connected   else    db   mysql connect

User · Answer

Try using PHP s mysql ping function   echo  mysql ping      true     false     You will need to prepend the     to suppose the MySQL Warnings you ll get for running this function without being connected to a database   There are other ways as well  but it depends on the code that you re using

[php] How do I check if PHP is connected to a database already?

Examples related to php

Examples related to mysql