IOS
OS X

Xcode 7.2+

Connection db("/tmp/example.db");
db.open();
db.exec("create table if not exists table_name(a int, b real, c text)");
db.exec("insert into table_name (a, b, c) values (10, 11.2, 'hello world')");

db.transaction(TransactionType::Deferred, [](Connection &con)->bool{
    con.exec("insert into table_name (a, b, c) values (1, 1.1, 'step one')");
    con.exec("insert into table_name (a, b, c) values (2, 2.2, 'step two')");
    return true;
});

Query query("select * from table_name", db);
while(query.next()) {
    query.intForName("a");
    query.floatForName("b");
    query.textForName("c");
}

Cursor cursor("insert into table_name (a, b, c) values (:a, :b, :c)", db);
cursor.bind(":a", 10);
cursor.bind(":b", 11.2);
cursor.bind(":c", "hello world");
cursor.exec();

Function *obj = Function::create("usql_string_len");
obj->setFunction([](sqlite3_context* context, std::vector<sqlite3_value *> &argv){
    if (argv.size() >= 1) {
        auto text = sqlite3_value_text(argv[0]);
        if (text) {
            int len = (int)std::strlen((const char *)text);
            sqlite3_result_int(context, len);
            return ;
        }
    }
    
    sqlite3_result_int(context, -1);
});
obj->setArgumentCount(1);
obj->deterministic = true;
db.registerFunction(obj);

AggregateFunction *agg = AggregateFunction::create("max_text_len");
static int maxLen = -1;
agg->setFunction([&](sqlite3_context* context, std::vector<sqlite3_value *> &argv){
    if (argv.size() >= 1) {
        auto text = sqlite3_value_text(argv[0]);
        if (text) {
            maxLen = std::max(maxLen, (int)std::strlen((const char *)text));
        }
    }
});
agg->setFinalFunction([](sqlite3_context *context){
    sqlite3_result_int(context, maxLen);
});
db.registerFunction(agg);