π¦ λ°μ΄ν° λ² μ΄μ€ (DB) π¦/π
Ύ μ€λΌν΄ DB & SQL
π μ¨λΌμΈ λ§μΌ(μΌνλͺ°) ν μ΄λΈ μμ
Meteora_
2021. 2. 17. 18:15
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μ¨λΌμΈ λ§μΌ TABLEμ λ§λ€μ΄λ³΄μΈμ.
μμ λ΄μ© β
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PRODUCT(μν) : μνλ²νΈ, μνλͺ , μνκ°κ²©, μνμ€λͺ
CONSUMER(μλΉμ) : μλΉμ ID, μ΄λ¦, λμ΄
CART(μ₯λ°κ΅¬λ) : μ₯λ°κ΅¬λ λ²νΈ, μλΉμ ID, μνλ²νΈ, μλ
μν ν
μ΄λΈμ μνμ λ±λ‘ν©λλ€(κ°μλ μνλ λλ‘).
μλΉμλ₯Ό λ±λ‘ν©λλ€.
μλΉμκ° μΌνν μνμ μΆκ°ν©λλ€.
μΌνν μνμ μΆλ ₯ν©λλ€.
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λμ

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--μν ν
μ΄λΈ
CREATE TABLE PRODUCT(
PRODUCTID NUMBER PRIMARY KEY,
NAME VARCHAR(50),
PRICE NUMBER,
PRODUCT_DESC VARCHAR2(500)
);
--μλΉμ ν
μ΄λΈ
CREATE TABLE CONSUMER(
USERID VARCHAR2(50) CONSTRAINT PK_USER PRIMARY KEY,
NAME VARCHAR2(50) NOT NULL,
AGE NUMBER(3)
);
--μ₯λ°κ΅¬λ ν
μ΄λΈ
CREATE TABLE CART(
CARTID NUMBER CONSTRAINT PK_CART PRIMARY KEY,
USERID VARCHAR2(50), -- μΈλν€
PRODUCTID NUMBER, -- μΈλν€
AMOUNT NUMBER
);
--μΈλν€ μμ±
ALTER TABLE CART
ADD
CONSTRAINT FK_PRODUCT_ID FOREIGN KEY(PRODUCTID)
REFERENCES PRODUCT(PRODUCTID);
ALTER TABLE CART
ADD
CONSTRAINT FK_USER_ID FOREIGN KEY(USERID)
REFERENCES CONSUMER(USERID);
--μνμ€
CREATE SEQUENCE PRODUCT_SEQ
INCREMENT BY 1
START WITH 1000;
--μνν
μ΄λΈμ μν λ±λ‘
INSERT INTO PRODUCT(PRODUCTID, NAME, PRICE, PRODUCT_DESC)
VALUES(PRODUCT_SEQ.NEXTVAL,'μμ°κΉ‘', 1500,'λ§μμ΄μ');
INSERT INTO PRODUCT(PRODUCTID, NAME, PRICE, PRODUCT_DESC)
VALUES(PRODUCT_SEQ.NEXTVAL,'ν¬ν
μ΄ν μΉ©', 2300,'μ§μ');
INSERT INTO PRODUCT(PRODUCTID, NAME, PRICE, PRODUCT_DESC)
VALUES(PRODUCT_SEQ.NEXTVAL,'컀νΌ', 2500,'λλ΄μ€μ');
--μλΉμλ₯Ό λ±λ‘ν©λλ€
INSERT INTO CONSUMER(USERID, NAME, AGE)
VALUES('HGD','νκΈΈλ',24);
INSERT INTO CONSUMER(USERID, NAME, AGE)
VALUES('SCH','μ±μΆν₯',16);
INSERT INTO CONSUMER(USERID, NAME, AGE)
VALUES('JSD','μ μλ',28);
-- μλΉμκ° μΌνν μνμ μΆκ°ν©λλ€.
INSERT INTO CART(CARTID, USERID, PRODUCTID, AMOUNT)
VALUES(1, 'SCH', 1001, 2);
INSERT INTO CART(CARTID, USERID, PRODUCTID, AMOUNT)
VALUES(2, 'SCH', 1000, 1);
INSERT INTO CART(CARTID, USERID, PRODUCTID, AMOUNT)
VALUES(3, 'HGD', 1001, 2);
-- μΌνν μνμ μΆλ ₯ν©λλ€.
SELECT *
FROM cart
WHERE userid = 'SCH';
SELECT c.userid, c.productid, p.name, p.price
FROM cart c, product p
WHERE c.productid = p.productid AND c.userid = 'SCH';
--μ±μΆν₯μ΄ λ μΌννλμ§ λμ΅λλ€.
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