Main public methods

QueryBuilder class

query($sql, $params[], $fetch_type) executes prepared $sql with $params. it can be used for custom queries
getSql() returns SQL query string which will be executed
getParams() returns an array of parameters for a query
getResult() returns query's results
getCount() returns results' rows count
getDriver() returns DB driver name in lowercase
hasError() returns true if an error is had
getErrorMessage() returns an error message if an error is had
setError($message) sets $error to true and $errorMessage
getFirst() returns the first item of results
getLast() returns the last item of results
reset() resets state to default values (except PDO property)
all() executes SQL query and returns all rows of result (fetchAll())
one() executes SQL query and returns the first row of result (fetch())
column($col) executes SQL query and returns the needed column of result by its name, col is 'id' by default
pluck($key, $col) executes SQL query and returns an array (the key (usually ID) and the needed column of result) by their names, key is id and col is '' by default
go() this method is for non SELECT queries. it executes SQL query and returns nothing (but returns the last inserted row ID for INSERT method)
count() prepares a query with SQL COUNT(*) function and executes it
exists() returns true if SQL query has at least one row and false if it hasn't

'SQL' methods are presented in the next section.