如何获取表中行的小计计数？

Question

我有这个SQL查询？

SELECT COUNT(*) FROM PHRASE WHERE JLPT = 1
SELECT COUNT(*) FROM PHRASE WHERE JLPT = 2
SELECT COUNT(*) FROM PHRASE WHERE JLPT = 3
SELECT COUNT(*) FROM PHRASE WHERE JLPT = 4

有没有办法可以将这些查询合并为1,以便计算出有多少JLPT行的值为1,2,3和4？

Answer 1

SELECT JLPT,
       COUNT(*)
FROM PHRASE
WHERE JLPT IN (1, 2, 3, 4)
GROUP BY JLPT;