ptgui中投影方式全画幅是什么意思

 因为这是面试问题，我不会为你使用MySql而是用TSQL回答（翻译虽然非常简单但我会为你做这个练习） 
 
 SQLFiddleDemo 
 
SELECT (tab.year * 12 + num) AS month
     ,value + 0.001 * num AS value
FROM tab 
CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5),
                   (6), (7), (8), (9), (10), (11)) AS t(num)
ORDER BY 1;
 
 这个怎么运作： 
 
 1）从选项卡获取数据 
 
 2）生成具有数字0-11的子查询的笛卡尔积，每行相互之间 
 
 3）在SELECT计算月份为tab.year * 12 + num和value并添加新别名 
 
 4）按月排序 
 
 再看看我没有使用任何循环，但我的解决方案是100％基于设置。 要用第二个表存储它我只需要SELECT ... INTO new_table_name... （TSQL）： 
 
 编辑： 
 
 演示 
 
CREATE TABLE tab(year INT, value NUMERIC(10,4));

INSERT INTO tab(year, value)
VALUES (18, 0.024), (19, 0.036), (20, 0.048), (21, 0.060);

CREATE TABLE new_table AS
SELECT (t.year * 12 + c.num) AS month
     ,t.value + ABS(t1.value-t.value)/12 * c.num AS value
FROM tab t
JOIN tab t1
  ON t.year = t1.year + 1
CROSS JOIN (SELECT 0 AS num      UNION ALL    SELECT 1     UNION ALL 
            SELECT 2             UNION ALL    SELECT 3     UNION ALL 
            SELECT 4             UNION ALL    SELECT 5     UNION ALL 
            SELECT 6             UNION ALL    SELECT 7     UNION ALL 
            SELECT 8             UNION ALL    SELECT 9    UNION ALL 
            SELECT 10            UNION ALL    SELECT 11) AS c

ORDER BY 1;

SELECT *
FROM new_table;

Because it is interview question, I won't answer for you using MySql but with TSQL (it is very trivial to translate though and I leave this exercise for you)
 
SQLFiddleDemo
 
SELECT (tab.year * 12 + num) AS month
     ,value + 0.001 * num AS value
FROM tab 
CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5),
                   (6), (7), (8), (9), (10), (11)) AS t(num)
ORDER BY 1;
 
How it works:
 
1) Get data from tab
 
2) Generate Cartesian Product with subquery of numbers 0 - 11, each row with each other
 
3) In SELECT calculate month as tab.year * 12 + num and value and add new aliases
 
4) Order by month
 
Second look that I didn't use any loop but my solution is 100% set based. To store it with second table I need only SELECT ... INTO new_table_name... (TSQL):
 
EDIT:
 
Demo
 
CREATE TABLE tab(year INT, value NUMERIC(10,4));

INSERT INTO tab(year, value)
VALUES (18, 0.024), (19, 0.036), (20, 0.048), (21, 0.060);

CREATE TABLE new_table AS
SELECT (t.year * 12 + c.num) AS month
     ,t.value + ABS(t1.value-t.value)/12 * c.num AS value
FROM tab t
JOIN tab t1
  ON t.year = t1.year + 1
CROSS JOIN (SELECT 0 AS num      UNION ALL    SELECT 1     UNION ALL 
            SELECT 2             UNION ALL    SELECT 3     UNION ALL 
            SELECT 4             UNION ALL    SELECT 5     UNION ALL 
            SELECT 6             UNION ALL    SELECT 7     UNION ALL 
            SELECT 8             UNION ALL    SELECT 9    UNION ALL 
            SELECT 10            UNION ALL    SELECT 11) AS c

ORDER BY 1;

SELECT *
FROM new_table;