How to prevent SQLITE SQLSTATE[HY000] [14]?

问题:

I receive sometimes the following error:

SQLSTATE[HY000] [14] unable to open database file

I open the datebase by using

new PDO("sqlite:database/datbase.db","","",array(
    PDO::ATTR_PERSISTENT => true
));

everytime I want read or write data from or to the database. The open process is the following function:

function opendatabase(){
try{
    return new PDO("sqlite:database/database.db","","",array(
        PDO::ATTR_PERSISTENT => true
    ));
}catch(PDOException $e){
    logerror($e->getMessage(), "opendatabase");
    print "Error in openhrsedb ".$e->getMessage();
}
}

After some time (sometime more than an hour, some times after some minutes I get the error message at the beginning of the post. How can I prevent such error?

回答1:

This is an error from SQLlite :

#define SQLITE_CANTOPEN 14 /* Unable to open the database file */

It seems like you have opened to many connections, I suggest you to reuse the connection if it is open.

Create a property:

private $pdo;

And check if it's null before creating a new object:

function opendatabase(){
    try{
        if($this->pdo==null){
          $this->pdo =new PDO("sqlite:database/database.db","","",array(
                PDO::ATTR_PERSISTENT => true
            ));
        }
        return $this->pdo;
    }catch(PDOException $e){
        logerror($e->getMessage(), "opendatabase");
        print "Error in openhrsedb ".$e->getMessage();
    }
}

回答2:

If anyone is having the same message while reusing the PDO connection and still having problems, it might be because you're storing images you get from fopen() and forgot the fclose() statement. In this particular case, the error message is really misleading. Here's a question for the same error message that I managed to solve after a few days of troubleshooting. SQLSTATE[HY000] [14] : can't open database because too many connections are already opened

回答3:

Very strange, but for me this was caused by not wrapping the new PDO statement in a try/catch block.