CREATE TABLE MES_t (x NUMBER(3), s VARCHAR2(50));

INSERT INTO MES_t VALUES (1, 'asd');
INSERT INTO MES_t VALUES (2, 'qwe');
INSERT INTO MES_t VALUES (3, 'zxc');

COMMIT

UPDATE MES_t
SET s = 'qwe', x = 100
WHERE s = 'asd';

COMMIT

SELECT * FROM MES_t WHERE x < 10;

SELECT s, SUM(x) FROM MES_t GROUP BY s;

DELETE FROM MES_t WHERE x < 10;

COMMIT

DROP TABLE MES_t