This is a complete example of all the commonly used SQLite related APIs. The aim is to get you up and running really fast. You can also get a runnable PHP file of of this tutorial.
Let's create a new database first. Create it only if the file doesn't exist and open it for reading/writing.
The extension of the file is up to you, but
.sqlite is pretty common and self-explanatory.
$db = new SQLite3('analytics.sqlite', SQLITE3_OPEN_CREATE | SQLITE3_OPEN_READWRITE);
$db->query('CREATE TABLE IF NOT EXISTS "visits" ( "id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "user_id" INTEGER, "url" VARCHAR, "time" DATETIME )');
It's advisable to wrap related queries in a transaction (with keywords
even if you don't care about atomicity. If you don't do this, SQLite automatically wraps every single query in a transaction, which slows down everything immensely. If you're new to SQLite, you may be surprised why the INSERTs are so slow .
$db->exec('BEGIN'); $db->query('INSERT INTO "visits" ("user_id", "url", "time") VALUES (42, "/test", "2017-01-14 10:11:23")'); $db->query('INSERT INTO "visits" ("user_id", "url", "time") VALUES (42, "/test2", "2017-01-14 10:11:44")'); $db->exec('COMMIT');
Insert potentially unsafe data with a prepared statement. You can do this with named parameters:
$statement = $db->prepare('INSERT INTO "visits" ("user_id", "url", "time") VALUES (:uid, :url, :time)'); $statement->bindValue(':uid', 1337); $statement->bindValue(':url', '/test'); $statement->bindValue(':time', date('Y-m-d H:i:s')); $statement->execute(); you can reuse the statement with different values
Let's fetch today's visits of user #42. We'll use a prepared statement again, but with numbered parameters this time, which are more concise:
$statement = $db->prepare('SELECT * FROM "visits" WHERE "user_id" = ? AND "time" >= ?'); $statement->bindValue(1, 42); $statement->bindValue(2, '2017-01-14'); $result = $statement->execute(); echo "Get the 1st row as an associative array:\n"; print_r($result->fetchArray(SQLITE3_ASSOC)); echo "\n"; echo "Get the next row as a numeric array:\n"; print_r($result->fetchArray(SQLITE3_NUM)); echo "\n";
Note: If there are no more rows, fetchArray() returns
false. You can take advantage of this in a
Free the memory - this in not done automatically, while your script is running
Here's a useful shorthand for fetching a single row as an associative array. The second parameter means we want all the selected columns.
Watch out, this shorthand doesn't support parameter binding, but you can escape the strings instead. Always put the values in SINGLE quotes! Double quotes are used for table and column names (similar to backticks in MySQL).
$query = 'SELECT * FROM "visits" WHERE "url" = \'' . SQLite3::escapeString('/test') . '\' ORDER BY "id" DESC LIMIT 1'; $lastVisit = $db->querySingle($query, true); echo "Last visit of '/test':\n"; print_r($lastVisit); echo "\n";
Another useful shorthand for retrieving just one value.
$userCount = $db->querySingle('SELECT COUNT(DISTINCT "user_id") FROM "visits"'); echo "User count: $userCount\n"; echo "\n";
Finally, close the database. This is done automatically when the script finishes, though.