PostgreSQL INSERT INTO table 从多个选择中获取的多条记录

Question

我有这3个tables

食谱：recipe_id | name

成分：ingredient_id | name

recipes_ingredients: id | recipe_id | ingredient_id

每个table的第一个id是SERIAL PRIMARY KEY，两个名字是character varying(50)。我正在尝试在 recipes_ingredients 中插入 recipe_id 和 ingredient_id，如果我使用单一成分进行操作，效果会很好。问题是我不知道如何插入与单个食谱关联的多种成分。

这是我尝试插入与同一食谱相关的 3 种不同成分的内容：

BEGIN;
WITH new_recipe AS (
    INSERT INTO recipe (name) VALUES ('{}') RETURNING recipe_id
), ingredient1 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
), ingredient2 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
), ingredient3 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
)
INSERT INTO recipes_ingredients (recipe_id, ingredient_id) 
SELECT new_recipe.recipe_id, ingredient1.ingredient_id FROM new_recipe CROSS JOIN ingredient1,
SELECT new_recipe.recipe_id, ingredient2.ingredient_id  FROM new_recipe CROSS JOIN ingredient2,
SELECT new_recipe.recipe_id, ingredient3.ingredient_id  FROM new_recipe CROSS JOIN ingredient3
COMMIT;

它给我这个错误：

ERROR:  syntax error at or near "SELECT"
LINE 13: SELECT new_recipe.recipe_id, ingredient2.ingredient_id  FROM...
         ^
SQL state: 42601
Character: 520

Answer 1

尝试在每个 select

之后用 union/union all 替换 ,

BEGIN;
WITH new_recipe AS (
    INSERT INTO recipe (name) VALUES ('{}') RETURNING recipe_id
), ingredient1 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
), ingredient2 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
), ingredient3 AS (
    INSERT INTO ingredient (name) VALUES ('{}') RETURNING ingredient_id
)
INSERT INTO recipes_ingredients (recipe_id, ingredient_id) 
SELECT new_recipe.recipe_id, ingredient1.ingredient_id FROM new_recipe CROSS JOIN ingredient1 Union
SELECT new_recipe.recipe_id, ingredient2.ingredient_id  FROM new_recipe CROSS JOIN ingredient2 Union
SELECT new_recipe.recipe_id, ingredient3.ingredient_id  FROM new_recipe CROSS JOIN ingredient3;
COMMIT;

PostgreSQL INSERT INTO table 从多个选择中获取的多条记录

PostgreSQL INSERT INTO table multiple records taken from multiple selects

sql

postgresql

cross-join

sql-insert

sql-returning