SELECT NOW();
SELECT CURDATE();
SELECT CURTIME();
SELECT YEAR(NOW()) 年;
SELECT YEAR('1998-1-1') 年;
SELECT YEAR(hiredate) 年 FROM employees;
SELECT MONTH(NOW()) 月;
SELECT MONTHNAME(NOW()) 月;
SELECT STR_TO_DATE('1998-3-2','%Y-%c-%d') AS out_put;
SELECT * FROM employees
WHERE hiredate = '1992-4-3';
SELECT * FROM employees
WHERE hiredate = STR_TO_DATE('4-3 1992','%c-%d %Y');
SELECT DATE_FORMAT(NOW(),'%y年%m月%d日') AS out_put;
SELECT last_name,DATE_FORMAT(hiredate,'%m月/%d日 %y年') 入职日期
FROM employees
WHERE commission_pct IS NOT NULL;