在 MySQL 中使用 INSERT 查询

Question

我正在尝试做一些我在 Postgresql 中几乎积极的工作：

WITH cte AS (SELECT something FROM something WHERE something.name='reference')
INSERT INTO somewhere (id, name)
SELECT cte.id, 'John'
UNION ALL
SELECT cte.id, 'Frank'
UNION ALL
SELECT cte.id, 'Thomas'
;

换句话说，我想获取“something”行以用于“somwhere”中的一堆新行。每个新条目都应该有一个引用（如外键值）回到 cte 中相同的“某物”行，主要是为了避免混乱。但是，MySQL 给了我“茫然凝视”语法错误机制。 MySQL 是否允许 WITH ... INSERT ...;？

这是实际代码；它只是设置测试数据：

WITH
  pr AS (SELECT pr_id from property AS p WHERE p.pr_name = 'Royal Oaks Plaza'),
  u AS (SELECT pr.pr_id AS pr_id, utyp.utyp_name AS utyp_name, utyp.utyp_id AS utyp_id FROM unit_type AS utyp, pr)
    INSERT INTO unit (pr_id, unt_number, utyp_id, unt_size)
    SELECT pr_id, '100', utyp_id, FLOOR(500 + RAND() * 2000)
      FROM u WHERE utyp_name = 'BEAUTY'
    UNION ALL
    SELECT pr_id, '110', utyp_id, FLOOR(500 + RAND() * 2000)
      FROM u WHERE utyp_name = 'RESTAURANT'
;

Answer 1

您可以尝试使用子查询来执行 UNION ALL 因为 CTE 只能在第一个查询中使用。

WITH cte AS (SELECT something FROM something WHERE something.name='reference')
INSERT INTO somewhere (id, name)
SELECT id,name
FROM (
    SELECT cte.id, 'John' name
    UNION ALL
    SELECT cte.id, 'Frank'
    UNION ALL
    SELECT cte.id, 'Thomas'
) t1;

所以您可以在查询中这样做

WITH
  pr AS (SELECT pr_id from property AS p WHERE p.pr_name = 'Royal Oaks Plaza'),
  u AS (SELECT pr.pr_id AS pr_id, utyp.utyp_name AS utyp_name, utyp.utyp_id AS utyp_id FROM unit_type AS utyp, pr)
    INSERT INTO unit (pr_id, unt_number, utyp_id, unt_size)
    SELECT pr_id,utyp_id,num
    FROM (
        SELECT pr_id, '100', utyp_id, FLOOR(500 + RAND() * 2000)
        FROM u WHERE utyp_name = 'BEAUTY'
        UNION ALL
        SELECT pr_id, '110', utyp_id, FLOOR(500 + RAND() * 2000) num
        FROM u WHERE utyp_name = 'RESTAURANT'
    ) t1
;

根据您的查询，我将重写为 IN 而不是 UNION ALL

WITH
  pr AS (SELECT pr_id from property AS p WHERE p.pr_name = 'Royal Oaks Plaza'),
  u AS (SELECT pr.pr_id AS pr_id, utyp.utyp_name AS utyp_name, utyp.utyp_id AS utyp_id FROM unit_type AS utyp, pr)
    INSERT INTO unit (pr_id, unt_number, utyp_id, unt_size)
    SELECT pr_id, '110', utyp_id, FLOOR(500 + RAND() * 2000) num
    FROM u 
    WHERE utyp_name IN ('RESTAURANT','BEAUTY')
    
;

Answer 2

在 MySQL 中，INSERT 在 CTE 定义之前，即

INSERT INTO somewhere (id, name)
WITH cte AS (SELECT id FROM something WHERE something.name='reference')
SELECT cte.id, 'John' FROM cte
UNION ALL
SELECT cte.id, 'Frank' FROM cte
UNION ALL
SELECT cte.id, 'Thomas' FROM cte;

Example on DB Fiddle

所以我认为以下方法可行：

INSERT INTO unit (pr_id, unt_number, utyp_id, unt_size)
WITH
  pr AS (SELECT pr_id from property AS p WHERE p.pr_name = 'Royal Oaks Plaza'),
  u AS (SELECT pr.pr_id AS pr_id, utyp.utyp_name AS utyp_name, utyp.utyp_id AS utyp_id FROM unit_type AS utyp, pr)
    SELECT pr_id, '100', utyp_id, FLOOR(500 + RAND() * 2000)
      FROM u WHERE utyp_name = 'BEAUTY'
    UNION ALL
    SELECT pr_id, '110', utyp_id, FLOOR(500 + RAND() * 2000)
      FROM u WHERE utyp_name = 'RESTAURANT'
;

Answer 3

mySQL“INSERT WITH”的概念验证脚本

CREATE TABLE fromm field char(10));
INSERT INTO fromm VALUES ('Hello!');
CREATE TABLE too field char(10));
INSERT INTO too (field) 
WITH pre AS 
( SELECT field f FROM fromm)
SELECT f FROM pre;
SELECT field FROM too;
DROP TABLE fromm;
DROP TABLE too;

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