如果数据库表的日期不连续怎么让他连续,在mybatis里怎么写关联sql让他的时间字段连续
时间: 2024-02-11 13:04:52 浏览: 16
在 MyBatis 中,您可以使用以下 SQL 语句来将日期字段连续化:
```sql
SELECT d.date, t.*
FROM (
SELECT DATE('2010-01-01') + INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY AS date
FROM (SELECT 0 AS a 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) AS a
CROSS JOIN (SELECT 0 AS a 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) AS b
CROSS JOIN (SELECT 0 AS a 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) AS c
WHERE DATE('2010-01-01') + INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY <= '2010-12-31'
) d
LEFT JOIN your_table t ON d.date = t.date_column
```
这个 SQL 查询会生成一个从 2010 年 1 月 1 日到 2010 年 12 月 31 日的日期列表,然后将其与你的表关联。请将 `your_table` 替换为你的表名,将 `date_column` 替换为你的日期字段名。
在 MyBatis 中,您可以使用 `<select>` 元素来定义您的查询语句。例如:
```xml
<select id="getContinuousData" resultType="your.package.YourDataClass">
SELECT d.date, t.*
FROM (
SELECT DATE('2010-01-01') + INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY AS date
FROM (SELECT 0 AS a 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) AS a
CROSS JOIN (SELECT 0 AS a 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) AS b
CROSS JOIN (SELECT 0 AS a 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) AS c
WHERE DATE('2010-01-01') + INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY <= '2010-12-31'
) d
LEFT JOIN your_table t ON d.date = t.date_column
</select>
```
请将 `your.package.YourDataClass` 替换为您的数据类的完整包名和类名。您还需要在您的 `SqlSessionFactory` 配置文件中定义这个 `<select>` 元素的 ID,并将其映射到您的 DAO 接口中。