public Object readValue(Object key) throws SQLException {
		PreparedStatement s =
			selectStatement.prepareIfNeeded(() -> db.prepareStatement(SELECT_STMT));
		Object value = null;
		s.setObject(1, key, keyType);
		try (ResultSet rs = s.executeQuery()) {
			if (rs.next()) {
				value = rs.getObject(1);
			}
		}
		return value;
	}
Given a key, retrieve the corresponding value
@param key identifies the table row
@return the value corresponding to the key
@throws SQLException for problems with the connection
Ghidra/Features/BSim/src/main/java/ghidra/features/bsim/query/client/tables/OptionalTable.java