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4.2 Programmatic API

The Programmatic API is based on JdbcTemplate and accesses the database with SQL strings as the primary interface. It is the lowest-level, most flexible relational database entry point in dbVisitor.

Best For​

  • You already have clear SQL and want lightweight execution.
  • SQL is complex — e.g. JOINs, subqueries, window functions, database-specific syntax.
  • You need direct control over batch execution, stored procedures, callbacks, or connection-level operations.
  • You do not want to set up object mapping for the current operation.

Not Best For​

  • Lots of single-table CRUD with repetitive SQL — consider Mapper API (BaseMapper) first.
  • You want DAO organized as interfaces — consider Mapper API first.
  • You want to generate SQL with chainable conditions — consider Builder API first.

Minimal Example​

With DataSource
DataSource dataSource = ...;
JdbcTemplate jdbc = new JdbcTemplate(dataSource);

List<User> users = jdbc.queryForList(
        "select * from users where age >= :age",
        CollectionUtils.asMap("age", 18),
        User.class);
With Connection
Connection conn = ...;
JdbcTemplate jdbc = new JdbcTemplate(conn);

List<User> users = jdbc.queryForList(
        "select * from users where age >= :age",
        CollectionUtils.asMap("age", 18),
        User.class);

Learn More​

  • JdbcTemplate: full capability entry point.
  • Parameter Passing: positional parameters, named parameters, interface-based parameter passing.
  • Result Handling: RowMapper, Map, ResultSetExtractor and other result processing approaches.