If you run a multiline SQL command (an INSERT, for example), and there is a SQL error in any of the lines, this function will recognize the error and return FALSE. However, any correct commands before the one with the error will still execute. Additionally, if you run changes() after such an incident, it will report that 0 rows have been changed, even though there were rows added to the table by the successful commands.
An example would be:
$dbo = new SQLiteDatabase("db/database.sqlite");
$dbo->query("CREATE TABLE foo(id INTEGER PRIMARY KEY, name CHAR(255));");
$ins_query = "INSERT INTO foo (name) VALUES ('Ilia1');
INSERT INTO foo (name) VALUES('Ilia2');
INSECT INTO foo (name) VALUES('Ilia3');";
$changes = $dbo->changes();
echo "<br />Rows changed: $changes<br />";
$tableArray = $dbo->arrayQuery("SELECT * FROM foo;");
echo "Table Contents\n";
The above code should show that 0 rows have been changed, but that there is new data in the table.