SQL旋转并计算存储为字符串的日期之间的差异- MySQL

SELECT STR_TO_DATE('2022-05-15', '%Y-%m-%d') AS date;

SELECT DATEDIFF(STR_TO_DATE('2022-05-20', '%Y-%m-%d'), STR_TO_DATE('2022-05-15', '%Y-%m-%d')) AS diff;

SELECT TIMESTAMPDIFF(HOUR, STR_TO_DATE('2022-05-15 12:00:00', '%Y-%m-%d %H:%i:%s'), STR_TO_DATE('2022-05-15 15:00:00', '%Y-%m-%d %H:%i:%s')) AS diff;

CREATE TABLE data (
    date VARCHAR(10),
    value INT
);

INSERT INTO data (date, value) VALUES ('2022-05-15', 10);
INSERT INTO data (date, value) VALUES ('2022-05-16', 15);
INSERT INTO data (date, value) VALUES ('2022-05-17', 20);

SELECT
    MAX(CASE WHEN date = '2022-05-15' THEN value END) AS '2022-05-15',
    MAX(CASE WHEN date = '2022-05-16' THEN value END) AS '2022-05-16',
    MAX(CASE WHEN date = '2022-05-17' THEN value END) AS '2022-05-17'
FROM data;