JDBC API Usage

Internal

• JDBC

JDBC Connection Life Cycle

JDBC Connection Life Cycle

Database Metadata

The database metadata is an object that contains metadata about the database the current connection belongs to.

Connection c = ...;
DatabaseMetaData dmd = c.getMetaData();

ResultSet

Some implementation will fail on ResultSet.first() invocation, if the result sent is not explicitly created to be ResultSet.TYPE_SCROLL_INSENSITIVE. Creating scrollable ResultSets may have performance implications. ResultSet.next() is always safe to use, in an integrator pattern.

Query

...

private DataSource dataSource;

...

Connection c;

try {

    c = dataSource.getConnection();

    PreparedStatement s = c.prepareStatement("SELECT * FROM SOME_TABLE");

    ResultSet rs = s.executeQuery();

    while(rs.next()) {

        //
        // columns are 1-based
        //

        String column1Value  = rs.getString(1);
        Long column2Value  = rs.getLong(2);

        ...
    }
}
finally {

    c.close();
}

More low-level JDBC code example with comments in SIA page 57.