gar*_*eld 3 common-table-expression mariadb
我在 Windows 7 上使用 Maria DB 版本 10.2.9,
MariaDB > select @@version;
+----------------+
| @@version |
+----------------+
| 10.2.9-MariaDB |
+----------------+
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我正在尝试使用递归 CTE 和 INSERT SELECT 来创建一些测试数据。为简单起见,下面列出了要填充的单列表:
CREATE TABLE cte_populated
(
id INT NOT NULL PRIMARY KEY
)
ENGINE = InnoDB;
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以及生成值 1 到 10 的 CTE:
WITH RECURSIVE int_seq AS (
SELECT 1 AS val
UNION ALL
SELECT val + 1
FROM int_seq
WHERE val < 10
)
INSERT cte_populated(id)
SELECT int_seq.val FROM int_seq;
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上面会产生语法错误。请注意,如果删除插入行,则 10 行将按预期显示,其中 SELECT 语句中的值为 1 到 10。
有谁知道有关在 INSERT/SELECT 查询中使用 CTE 的限制或任何解决方法?
更新:以下两个查询有效,一个来自 @elenst 回复,另一个来自 @PM 77 评论中提供的链接:
INSERT cte_populated(id)
WITH RECURSIVE int_seq AS (
SELECT 1 AS val
UNION ALL
SELECT val + 1
FROM int_seq
WHERE val < 10)
SELECT int_seq.val as id FROM int_seq;
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以下内容改编自@PM 77 提供的链接。
INSERT INTO cte_populated
WITH RECURSIVE int_seq(val) AS (
SELECT 1
UNION ALL
SELECT 1 + val FROM int_seq WHERE val < 10)
SELECT * FROM int_seq;
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这里没有限制,你只需要按照语法相反的方式进行即可:
INSERT cte_populated(id)
WITH RECURSIVE int_seq AS (
SELECT 1 AS val
UNION ALL
SELECT val + 1
FROM int_seq
WHERE val < 10
)
SELECT int_seq.val FROM int_seq;
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更新:为了回应它仍然导致错误的说法,添加实际的客户端输出:
MariaDB [test]> CREATE TABLE `cte_populated` (
-> `id` int(11) DEFAULT NULL
-> ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
Query OK, 0 rows affected (0.21 sec)
MariaDB [test]> INSERT cte_populated(id)
-> WITH RECURSIVE int_seq AS (
-> SELECT 1 AS val
-> UNION ALL
-> SELECT val + 1
-> FROM int_seq
-> WHERE val < 10)
-> SELECT int_seq.val as id FROM int_seq;
Query OK, 10 rows affected (0.04 sec)
Records: 10 Duplicates: 0 Warnings: 0
MariaDB [test]> SELECT * FROM cte_populated;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
| 10 |
+------+
10 rows in set (0.00 sec)
MariaDB [test]> select @@version;
+----------------+
| @@version |
+----------------+
| 10.2.9-MariaDB |
+----------------+
1 row in set (0.00 sec)
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