Question

I have a situation where I have to update a web site on a shared hosting provider. The site has a CMS. Uploading the CMS’s files is pretty straightforward using FTP.

I also have to import a big (relative to the confines of a PHP script) database file (Around 2-3 MB uncompressed). Mysql is closed for access from the outside, so I have to upload a file using FTP, and start a PHP script to import it. Sadly, I do not have access to the mysql command line function so I have to parse and query it using native PHP. I also can’t use LOAD DATA INFILE. I also can’t use any kind of interactive front-end like phpMyAdmin, it needs to run in an automated fashion. I also can’t use mysqli_multi_query().

Does anybody know or have a already coded, simple solution that reliably splits such a file into single queries (there could be multi-line statements) and runs the query. I would like to avoid to start fiddling with it myself due to the many gotchas that I’m likely to come across (How to detect whether a field delimiter is part of the data; how to deal with line breaks in memo fields; and so on). There must be a ready made solution for this.

Answer 1

Here is a memory-friendly function that should be able to split a big file in individual queries without needing to open the whole file at once:

function SplitSQL($file, $delimiter = ';')
{
    set_time_limit(0);

    if (is_file($file) === true)
    {
        $file = fopen($file, 'r');

        if (is_resource($file) === true)
        {
            $query = array();

            while (feof($file) === false)
            {
                $query[] = fgets($file);

                if (preg_match('~' . preg_quote($delimiter, '~') . '\s*$~iS', end($query)) === 1)
                {
                    $query = trim(implode('', $query));

                    if (mysql_query($query) === false)
                    {
                        echo '<h3>ERROR: ' . $query . '</h3>' . "\n";
                    }

                    else
                    {
                        echo '<h3>SUCCESS: ' . $query . '</h3>' . "\n";
                    }

                    while (ob_get_level() > 0)
                    {
                        ob_end_flush();
                    }

                    flush();
                }

                if (is_string($query) === true)
                {
                    $query = array();
                }
            }

            return fclose($file);
        }
    }

    return false;
}

I tested it on a big phpMyAdmin SQL dump and it worked just fine.

---

Some test data:

CREATE TABLE IF NOT EXISTS "test" (
    "id" INTEGER PRIMARY KEY AUTOINCREMENT,
    "name" TEXT,
    "description" TEXT
);

BEGIN;
    INSERT INTO "test" ("name", "description")
    VALUES (";;;", "something for you mind; body; soul");
COMMIT;

UPDATE "test"
    SET "name" = "; "
    WHERE "id" = 1;

And the respective output:

SUCCESS: CREATE TABLE IF NOT EXISTS "test" ( "id" INTEGER PRIMARY KEY AUTOINCREMENT, "name" TEXT, "description" TEXT );
SUCCESS: BEGIN;
SUCCESS: INSERT INTO "test" ("name", "description") VALUES (";;;", "something for you mind; body; soul");
SUCCESS: COMMIT;
SUCCESS: UPDATE "test" SET "name" = "; " WHERE "id" = 1;