The join method between ORACLE tables

The join method between ORACLE tables

1. inner join
2. left join
3. right join
4. natural connection
5. full connection
6. Cartesian connection

Create test data

CREATE TABLE TMP_TB_1(
USER_ID   NUMBER(10,0),
USER_NAME VARCHAR2(30),
ADDRESS   VARCHAR2(50)
);

CREATE TABLE TMP_TB_2(
USER_ID   NUMBER(10,0),
USER_NAME VARCHAR2(30),
U_ADDRESS   VARCHAR2(50)
);

-- 插入数据
INSERT INTO TMP_TB_1 VALUES (1,'小明','李家胡同');
INSERT INTO TMP_TB_1 VALUES (2,'李君','李家胡同');
INSERT INTO TMP_TB_1 VALUES (3,'小黑','五里坨');
INSERT INTO TMP_TB_1 VALUES (4,'提提','南宫');
INSERT INTO TMP_TB_1 VALUES (7,'酷酷','大红门');
INSERT INTO TMP_TB_1 VALUES (8,'李老师','天安门');
SELECT * FROM TMP_TB_1;

-- 插入数据
INSERT INTO TMP_TB_2 VALUES (1,'小明','李家胡同');
INSERT INTO TMP_TB_2 VALUES (2,'李君','李家胡同');
INSERT INTO TMP_TB_2 VALUES (3,'小宝宝','卡瓦挖');
INSERT INTO TMP_TB_2 VALUES (5,'多多','国贸');
INSERT INTO TMP_TB_2 VALUES (6,'荣荣','上京');
SELECT * FROM TMP_TB_2;

1 inner join

SELECT A.*,B.*
  FROM TMP_TB_1 A, TMP_TB_2 B
  WHERE A.USER_ID = B.USER_ID;

SELECT A.*,B.*
  FROM TMP_TB_1 A JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID;

SELECT A.*,B.*
  FROM TMP_TB_1 A INNER JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID;

2 left outer join

SELECT A.*,B.*
  FROM TMP_TB_1 A, TMP_TB_2 B
  WHERE A.USER_ID = B.USER_ID(+);

SELECT A.*,B.*
  FROM TMP_TB_1 A 
  LEFT JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID;

SELECT A.*,B.*
  FROM TMP_TB_1 A 
  LEFT OUTER JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID;

Left (outer) join with filter

-- 先筛选后联接
SELECT A.*,B.*
  FROM TMP_TB_1 A, TMP_TB_2 B
  WHERE A.USER_ID = B.USER_ID(+)
    AND B.U_ADDRESS(+) = '李家胡同';

SELECT A.*,B.*
  FROM TMP_TB_1 A 
  LEFT JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID
    AND B.U_ADDRESS = '李家胡同';

-- 左外联接 联接后根据条件筛选
SELECT A.*,B.*
  FROM TMP_TB_1 A, TMP_TB_2 B
  WHERE A.USER_ID = B.USER_ID(+)
    AND B.U_ADDRESS = '李家胡同';

SELECT A.*,B.*
  FROM TMP_TB_1 A 
  LEFT JOIN TMP_TB_2 B
    ON A.USER_ID = B.USER_ID
 WHERE B.U_ADDRESS = '李家胡同';

3 Right (outer) join and left (outer) join

4 Natural connections

 SELECT *
  FROM TMP_TB_1 A 
  NATURAL JOIN TMP_TB_2 B;

5 full (outer) join

 SELECT *
  FROM TMP_TB_1 A 
  FULL JOIN TMP_TB_2 B
   ON A.USER_ID = B.USER_ID AND A.USER_NAME = B.USER_NAME;

  SELECT *
  FROM TMP_TB_1 A 
  FULL OUTER JOIN TMP_TB_2 B
   ON A.USER_ID = B.USER_ID;

 SELECT *
  FROM TMP_TB_1 A 
  FULL JOIN TMP_TB_2 B
   ON A.USER_ID = B.USER_ID AND A.USER_NAME = B.USER_NAME;

6 Cartesian product

SELECT *
  FROM TMP_TB_1 A, TMP_TB_2 B;

 SELECT *
  FROM TMP_TB_1 A 
  CROSS JOIN TMP_TB_2 B;