sqlite::query

SELECT wrapper returning sqlite::result

Inherits from sqlite::command, but adds a range-based iteration API via each(). Bind values using bind() or %, then loop over query.each() with a range-based for to consume rows through the lightweight row_view proxy (supports column access by index or name).

Use cases

  • Column-name lookups are cached per statement, so repeated row["column"] calls remain O(1).
  • each() is single-pass by design. Grab get_result() if you need to hold on to the cursor, rewind it, or interleave iteration with other work.
  • The class enforces correct usage—attempting to iterate without finishing the previous each() will throw database_misuse_exception.

Public API

MemberDescription
query(connection& con, std::string const& sql)Compiles the SELECT statement.
query(query const&)=delete, query& operator=(query const&)=deleteNon-copyable.
~query()Inherits command's cleanup.
result_range each()Returns a single-pass range whose iterators yield row_view proxies for use in range-based for loops. Each proxy exposes get<T>() by index or name.
result_type get_result()Constructs a manual sqlite::result cursor for low-level access.
result_type emit_result() (deprecated)Legacy helper that executed the statement once; prefer each() or get_result().

result_range exposes an iterator type that models an input-iterator. Dereferencing yields a row_view proxy, letting you call get<T>() inside the loop.

Example usage

Stream rows with each(), optionally passing bind arguments inline, or grab get_result() when you need to pause iteration, rewind, or share the cursor with another consumer. 

sqlite::query q(db, "SELECT id, text FROM notes WHERE project = ?");
for (auto & row : q.each("docs")) {
    auto id = row.get<std::int64_t>("id");
    auto text = row.get<std::string_view>(1);
    fmt::print(\"[#{}] {}\\n\", id, text);
}
sqlite::query filtered(db, "SELECT message FROM audit WHERE level = ? AND tag = ?");
filtered % "warn";
for (auto & row : filtered.each("ui")) {
    log(row.get<std::string>(0));
}
sqlite::query named_q(db, "SELECT body FROM notes WHERE project = :project");
for (auto & row : named_q.each(sqlite::named(":project", "docs"))) {
    consume(row.get<std::string>(0));
}
auto cursor = q.get_result();    // manual control
while (cursor->next_row()) {
    if (cursor->get_column_name(0) == \"id\") {
        // ...
    }
}