-- create a table
CREATE TABLE `table` (
  id INTEGER PRIMARY KEY,
  key TEXT NOT NULL,
  value TEXT NOT NULL
);
-- insert some values
INSERT INTO `table` VALUES (1, 'moscow', 'tver');
INSERT INTO `table` VALUES (2, 'moscow', 'moscow');
INSERT INTO `table` VALUES (3, 'spb', 'klin');
INSERT INTO `table` VALUES (4, 'spb', 'spb');
INSERT INTO `table` VALUES (5, 'klin', 'klin');
INSERT INTO `table` VALUES (6, 'kaluga', 'perm');
-- fetch some values
SELECT * FROM `table` WHERE key = value;