Query Concepts

SqlMan keeps SQL visible. An Action contains the connection, SQL text, parameters, and database vendor. Calling query(...) creates a Query, which executes the statement and maps its result.

Query query = new Action(
        conn,
        "SELECT id, name FROM shop_address WHERE stat = ?"
).query(1);

One row

Return the first row as a Map:

Map<String, Object> row = query.one();

Return the first row as a JavaBean:

Address address = query.one(Address.class);

If the query has no row, both methods return null.

One value

For a single-column result, use oneValue(...):

Integer total = new Action(
        conn,
        "SELECT COUNT(*) FROM shop_address WHERE stat = ?"
).query(1).oneValue(Integer.class);

Multiple rows

List<Map<String, Object>> rows =
        new Action(conn, "SELECT * FROM shop_address ORDER BY id")
                .query()
                .list();

List<Address> addresses =
        new Action(conn, "SELECT * FROM shop_address ORDER BY id")
                .query()
                .list(Address.class);

An empty multi-row query currently returns null; callers that require a collection can normalize it with Collections.emptyList().

Resource handling

Query closes its PreparedStatement and ResultSet. The caller owns the Connection and must close or return it to the pool.