ORA-00979：単純な例

Question

と表現BYないGROUP私は、Oracle 11gで、次の例を試してみました：http://joshualande.com/filters-joins-aggregations/

SELECT c.recipe_name, 
COUNT(a.ingredient_id), 
SUM(a.amount*b.ingredient_price) 
FROM recipe_ingredients a 
JOIN ingredients b 
ON a.ingredient_id = b.ingredient_id 
JOIN recipes c 
ON a.recipe_id = c.recipe_id 
GROUP BY a.recipe_id; 

私はSQLエラーを取得：クエリで使用ORA-00979: not a GROUP BY expression...

テーブルを

CREATE TABLE recipes (
    recipe_id INT NOT NULL, 
    recipe_name VARCHAR(30) NOT NULL, 
    PRIMARY KEY (recipe_id), 
    UNIQUE (recipe_name) 
); 

INSERT INTO RECIPES (RECIPE_ID, RECIPE_NAME) VALUES (1, 'Tacos'); 
INSERT INTO RECIPES (recipe_id, recipe_name) VALUES (2, 'Tomato Soup'); 
INSERT INTO RECIPES (recipe_id, recipe_name) VALUES (3, 'Grilled Cheese'); 

CREATE TABLE ingredients (
    ingredient_id INT NOT NULL, 
    ingredient_name VARCHAR(30) NOT NULL, 
    ingredient_price INT NOT NULL, 
    PRIMARY KEY (ingredient_id), 
    UNIQUE (ingredient_name) 
); 

INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (1, 'Beef', 5); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (2, 'Lettuce', 1); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (3, 'Tomatoes', 2); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (4, 'Taco Shell', 2); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (5, 'Cheese', 3); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (6, 'Milk', 1); 
INSERT INTO ingredients (ingredient_id, ingredient_name, ingredient_price) VALUES (7, 'Bread', 2); 

CREATE TABLE recipe_ingredients (
    recipe_id int NOT NULL, 
    ingredient_id INT NOT NULL, 
    amount INT NOT NULL, 
    PRIMARY KEY (recipe_id,ingredient_id) 
); 

INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (1,1,1); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (1,2,2); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (1,3,2); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (1,4,3); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (1,5,1); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (2,3,2); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (2,6,1); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (3,5,1); 
INSERT INTO recipe_ingredients (recipe_id, ingredient_id, amount) VALUES (3,7,2); 

私はこの質問が既に何度か尋ねられたことは知っていますが、plzはこの例を私に説明しています。

Answer 1

、あなただけのGROUP BY句に表示されるか（SUMなど）集計されているかという表現を参照することができます。 c.recipe_nameはそのようにはなりません。

a.recipe_idでグループ化すると、c.recipe_name（各グループ内）のユニークな結果につながることがあります。そして、オラクルはこの情報も引き出す​​ことができるかもしれません。しかし、SQLはより厳密で、式をGROUP BY句に入れる必要があります。

だから、単に書く：

SELECT c.recipe_name, 
    COUNT(a.ingredient_id), 
    SUM(a.amount*b.ingredient_price) 
FROM recipe_ingredients a 
JOIN ingredients b 
    ON a.ingredient_id = b.ingredient_id 
JOIN recipes c 
    ON a.recipe_id = c.recipe_id 
GROUP BY a.recipe_id, c.recipe_name; 

Answer 2

またGROUP BY句でフィールドc.recipe_nameを配置する必要があります：あなたのクエリと

SELECT c.recipe_name, 
     COUNT(a.ingredient_id) AS cnt, 
     SUM(a.amount*b.ingredient_price) AS sum 
FROM recipe_ingredients a 
JOIN ingredients b 
    ON a.ingredient_id = b.ingredient_id 
JOIN recipes c 
    ON a.recipe_id = c.recipe_id 
GROUP BY c.recipe_name, a.recipe_id; 

問題は、非凝集列は、c.recipe_nameのように、SELECT句に表示されていることです。

出力：SELECT句で

recipe_name  cnt sum 
------------------------ 
Grilled Cheese 2 7 
Tacos   5 20 
Tomato Soup  2 5 

Answer 3

SELECT 
    c.recipe_name, 
    COUNT(a.ingredient_id), 
    SUM(a.amount*b.ingredient_price) 
FROM recipe_ingredients a 
JOIN ingredients b 
    ON a.ingredient_id = b.ingredient_id 
JOIN recipes c 
    ON a.recipe_id = c.recipe_id 
GROUP BY c.recipe_name