• cheat sheet

  SELECT * FROM table WHERE col=1 GROUP by ... HAVING count(*)>1 ORDER BY col;
  UPDATE table SET col=1 WHERE col=1;
  INSERT INTO table (ID,NAME) VALUES (1,'Labs');
  INSERT INTO table (ID,NAME) SELECT id,name FROM table;

• remove-duplicate-rows，删除重复行

  DELETE e1 FROM EMPLOYEE e1, EMPLOYEE e2 WHERE e1.name = e2.name AND e1.id > e2.id;

• SQL Data Types，SQL数据类型
• oracle