Oracle PL/SQL/Table Joins/Left Outer Join
Содержание
A left outer join:the outer join operator appears on the right of the equality operator
<source lang="sql">
SQL> -- create demo table SQL> create table Employee(
2 empno Number(3) NOT NULL, -- Employee ID 3 ename VARCHAR2(10 BYTE), -- Employee Name 4 hireDate DATE, -- Date Employee Hired 5 orig_salary Number(8,2), -- Orignal Salary 6 curr_salary Number(8,2), -- Current Salary 7 region VARCHAR2(1 BYTE) -- Region where employeed 8 ) 9 /
Table created. SQL> SQL> create table job(
2 empno Number(3) NOT NULL, -- Employee ID 3 jobtitle VARCHAR2(10 BYTE) -- Employee job title 4 ) 5 /
Table created. SQL> -- prepare data for employee table SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(122,"Alison",to_date("19960321","YYYYMMDD"), 45000, 48000, "E")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(123, "James",to_date("19781212","YYYYMMDD"), 23000, 32000, "W")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(104,"Celia",to_date("19821024","YYYYMMDD"), 53000, 58000, "E")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(105,"Robert",to_date("19840115","YYYYMMDD"), 31000, 36000, "W")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(116,"Linda", to_date("19870730","YYYYMMDD"), 43000, 53000, "E")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(117,"David", to_date("19901231","YYYYMMDD"), 78000, 85000, "W")
3 /
1 row created. SQL> insert into Employee(empno, ename, hireDate, orig_salary, curr_salary, region)
2 values(108,"Jode", to_date("19960917","YYYYMMDD"), 21000, 29000, "E")
3 /
1 row created. SQL> SQL> -- prepare data for job table SQL> SQL> insert into job(empno, jobtitle)
2 values(101, "Painter");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(122, "Tester");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(123, "Dediator");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(104, "Chemist");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(105, "Accountant");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(116, "Manager");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(117, "Programmer");
1 row created. SQL> SQL> insert into job(empno, jobtitle)
2 values(108, "Developer");
1 row created. SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
EMPNO ENAME HIREDATE ORIG_SALARY CURR_SALARY R
---------- --------- ----------- ----------- -
122 Alison 21-MAR-96 45000 48000 E
123 James 12-DEC-78 23000 32000 W
104 Celia 24-OCT-82 53000 58000 E
105 Robert 15-JAN-84 31000 36000 W
116 Linda 30-JUL-87 43000 53000 E
117 David 31-DEC-90 78000 85000 W
108 Jode 17-SEP-96 21000 29000 E
7 rows selected. SQL> SQL> select * from job;
EMPNO JOBTITLE
----------
101 Painter
122 Tester
123 Dediator
104 Chemist
105 Accountant
116 Manager
117 Programmer
108 Developer
8 rows selected. SQL> SQL> SQL> SQL> SQL> -- A left outer join:the outer join operator appears on the right of the equality operator: SQL> SQL> SELECT e.ename, j.jobtitle
2 FROM employee e, job j 3 WHERE e.empno = j.empno(+) ;
ENAME JOBTITLE
----------
Alison Tester James Dediator Celia Chemist Robert Accountant Linda Manager David Programmer Jode Developer 7 rows selected. SQL> SQL> SQL> SQL> drop table job; Table dropped. SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL>
</source>
Left join with plus sign
<source lang="sql">
SQL> SQL> create table emp
2 ( empno NUMBER(4) constraint E_PK primary key 3 , ename VARCHAR2(8) 4 , init VARCHAR2(5) 5 , job VARCHAR2(8) 6 , mgr NUMBER(4) 7 , bdate DATE 8 , sal NUMBER(6,2) 9 , comm NUMBER(6,2) 10 , deptno NUMBER(2) default 10 11 ) ;
Table created. SQL> insert into emp values(1,"Tom","N", "Coder", 13,date "1965-12-17", 800 , NULL, 20); 1 row created. SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20", 1600, 300, 30); 1 row created. SQL> insert into emp values(3,"Wil","TF" , "Tester",6,date "1962-02-22", 1250, 500, 30); 1 row created. SQL> insert into emp values(4,"Jane","JM", "Designer", 9,date "1967-04-02", 2975, NULL, 20); 1 row created. SQL> insert into emp values(5,"Mary","P", "Tester",6,date "1956-09-28", 1250, 1400, 30); 1 row created. SQL> insert into emp values(6,"Black","R", "Designer", 9,date "1963-11-01", 2850, NULL, 30); 1 row created. SQL> insert into emp values(7,"Chris","AB", "Designer", 9,date "1965-06-09", 2450, NULL, 10); 1 row created. SQL> insert into emp values(8,"Smart","SCJ", "Coder", 4,date "1959-11-26", 3000, NULL, 20); 1 row created. SQL> insert into emp values(9,"Peter","CC", "Designer",NULL,date "1952-11-17", 5000, NULL, 10); 1 row created. SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28", 1500, 0, 30); 1 row created. SQL> insert into emp values(11,"Ana","AA", "Coder", 8,date "1966-12-30", 1100, NULL, 20); 1 row created. SQL> insert into emp values(12,"Jane","R", "Manager", 6,date "1969-12-03", 800 , NULL, 30); 1 row created. SQL> insert into emp values(13,"Fake","MG", "Coder", 4,date "1959-02-13", 3000, NULL, 20); 1 row created. SQL> insert into emp values(14,"Mike","TJA","Manager", 7,date "1962-01-23", 1300, NULL, 10); 1 row created. SQL> SQL> create table departments
2 ( deptno NUMBER(2) constraint D_PK primary key 3 , dname VARCHAR2(10) 4 , location VARCHAR2(8) 5 , mgr NUMBER(4) 6 ) ;
Table created. SQL> SQL> insert into departments values (10,"ACCOUNTING","NEW YORK",7); 1 row created. SQL> insert into departments values (20,"TRAINING", "DALLAS", 4); 1 row created. SQL> insert into departments values (30,"SALES", "CHICAGO", 6); 1 row created. SQL> insert into departments values (40,"HR", "BOSTON", 9); 1 row created. SQL> SQL> SQL> select d.deptno, d.location
2 , e.ename, e.init 3 from emp e, departments d 4 where e.deptno(+) = d.deptno 5 order by d.deptno, e.ename; DEPTNO LOCATION ENAME INIT
-------- -------- -----
10 NEW YORK Chris AB
10 NEW YORK Mike TJA
10 NEW YORK Peter CC
20 DALLAS Ana AA
20 DALLAS Fake MG
20 DALLAS Jane JM
20 DALLAS Smart SCJ
20 DALLAS Tom N
30 CHICAGO Black R
30 CHICAGO Jack JAM
30 CHICAGO Jane R
30 CHICAGO Mary P
30 CHICAGO Take JJ
30 CHICAGO Wil TF
40 BOSTON
15 rows selected. SQL> SQL> drop table emp; Table dropped. SQL> drop table departments; Table dropped.
</source>
left outer join between employee table and department table
<source lang="sql">
SQL> SQL> CREATE TABLE departments
2 (department_id number(10) not null, 3 department_name varchar2(50) not null, 4 CONSTRAINT departments_pk PRIMARY KEY (department_id) 5 );
Table created. SQL> SQL> SQL> SQL> insert into departments ( department_id, department_name )
2 values( 1, "Data Group" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 2, "Purchasing" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 3, "Call Center" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 4, "Communication" );
1 row created. SQL> SQL> SQL> SQL> CREATE TABLE employees
2 ( employee_id number(10) not null, 3 last_name varchar2(50) not null, 4 email varchar2(30), 5 hire_date date, 6 job_id varchar2(30), 7 department_id number(10), 8 salary number(6), 9 manager_id number(6), 10 CONSTRAINT employees_pk PRIMARY KEY (employee_id), 11 CONSTRAINT fk_departments FOREIGN KEY (department_id) REFERENCES departments(department_id) 12 );
Table created. SQL> SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary,department_id ,manager_id)
2 values ( 1001, "Lawson", "lawson@g.ru", "01-JAN-2002","MGR", 30000,1 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values ( 1002, "Wells", "wells@g.ru", "01-JAN-2002", "DBA", 20000,2, 1005 );
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values( 1003, "Bliss", "bliss@g.ru", "01-JAN-2002", "PROG", 24000,3 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1004, "Kyte", "tkyte@a.ru", SYSDATE-3650, "MGR",25000 ,4, 1005);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1005, "Viper", "sdillon@a .ru", SYSDATE, "PROG", 20000, 1, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id,manager_id)
2 values( 1006, "Beck", "clbeck@g.ru", SYSDATE, "PROG", 20000, 2, null);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1007, "Java", "java01@g.ru", SYSDATE, "PROG", 20000, 3, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1008, "Oracle", "wvelasq@g.ru", SYSDATE, "DBA", 20000, 4, 1006);
1 row created. SQL> SQL> select * from employees; EMPLOYEE_ID LAST_NAME EMAIL HIRE_DATE JOB_ID DEPARTMENT_ID SALARY MANAGER_ID
-------------------------------------------------- ------------------------------ --------- ------------------------------ ------------- ---------- ----------
1001 Lawson lawson@g.ru 01-JAN-02 MGR 1 30000 1004
1002 Wells wells@g.ru 01-JAN-02 DBA 2 20000 1005
1003 Bliss bliss@g.ru 01-JAN-02 PROG 3 24000 1004
1004 Kyte tkyte@a.ru 13-JUN-98 MGR 4 25000 1005
1005 Viper sdillon@a .ru 10-JUN-08 PROG 1 20000 1006
1006 Beck clbeck@g.ru 10-JUN-08 PROG 2 20000
1007 Java java01@g.ru 10-JUN-08 PROG 3 20000 1006
EMPLOYEE_ID LAST_NAME EMAIL HIRE_DATE JOB_ID DEPARTMENT_ID SALARY MANAGER_ID
-------------------------------------------------- ------------------------------ --------- ------------------------------ ------------- ---------- ----------
1008 Oracle wvelasq@g.ru 10-JUN-08 DBA 4 20000 1006
8 rows selected. SQL> SQL> select * from departments; DEPARTMENT_ID DEPARTMENT_NA
-------------
1 Data Group
2 Purchasing
3 Call Center
4 Communication
4 rows selected. SQL> SQL> SQL> SQL> select e.employee_id, e.last_name, d.department_name
2 from employees e left outer join departments d 3 on e.department_id = d.department_id 4 where e.job_id = "MGR" 5 /
EMPLOYEE_ID LAST_NAME DEPARTMENT_NA
-------------------------------------------------- -------------
1001 Lawson Data Group
1004 Kyte Communication
SQL> SQL> SQL> drop table employees cascade constraints; Table dropped. SQL> drop table departments cascade constraints; Table dropped. SQL> SQL>
</source>
Left outer join demo
<source lang="sql">
SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
2 ENAME VARCHAR2(10), 3 JOB VARCHAR2(9), 4 MGR NUMBER(4), 5 HIREDATE DATE, 6 SAL NUMBER(7, 2), 7 COMM NUMBER(7, 2), 8 DEPTNO NUMBER(2));
Table created. SQL> SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK", 7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7521, "WARD", "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER", 7839, TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> CREATE TABLE DEPT (DEPTNO NUMBER(2),DNAME VARCHAR2(14),LOC VARCHAR2(13) ); Table created. SQL> SQL> INSERT INTO DEPT VALUES (10, "ACCOUNTING", "NEW YORK"); 1 row created. SQL> INSERT INTO DEPT VALUES (20, "RESEARCH", "DALLAS"); 1 row created. SQL> INSERT INTO DEPT VALUES (30, "SALES", "CHICAGO"); 1 row created. SQL> INSERT INTO DEPT VALUES (40, "OPERATIONS", "BOSTON"); 1 row created. SQL> SQL> SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 09-DEC-82 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 12-JAN-83 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected. SQL> SQL> select * from dept;
DEPTNO DNAME LOC
-------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> SQL> SQL> SQL> SQL> SQL> select e1.ename "Employee",
2 e2.ename "Reports To" 3 from emp e1 left outer join emp e2 4 on e1.MGR = e2.empno 5 order by e1.empno;
Employee Reports To
----------
SMITH FORD ALLEN BLAKE WARD BLAKE JONES KING MARTIN BLAKE BLAKE KING CLARK KING SCOTT JONES KING TURNER BLAKE ADAMS SCOTT JAMES BLAKE FORD JONES MILLER CLARK 14 rows selected. SQL> SQL> SQL> drop table dept; Table dropped. SQL> drop table emp; Table dropped. SQL> SQL> SQL>
</source>
LEFT OUTER JOIN tableName ON joined columns
<source lang="sql">
SQL> SQL> CREATE TABLE emps (
2 emp varchar(30) 3 ,title varchar(30) 4 );
Table created. SQL> SQL> INSERT INTO emps VALUES ("Tom","Programmer"); 1 row created. SQL> INSERT INTO emps VALUES ("Jack","Tester"); 1 row created. SQL> INSERT INTO emps VALUES ("Mary","Technician"); 1 row created. SQL> SQL> CREATE TABLE JobLevel (
2 title varchar(30) 3 ,rank varchar(30) 4 );
Table created. SQL> SQL> INSERT INTO JobLevel VALUES ("Programmer","Level1"); 1 row created. SQL> INSERT INTO JobLevel VALUES ("Tester","Level2"); 1 row created. SQL> INSERT INTO JobLevel VALUES ("Technician","Level3"); 1 row created. SQL> SQL> CREATE TABLE salary (
2 rank varchar(30) 3 ,payment DECIMAL(10,2) 4 );
Table created. SQL> SQL> INSERT INTO salary VALUES ("Level1",2000.00); 1 row created. SQL> INSERT INTO salary VALUES ("Level2",3000.00); 1 row created. SQL> INSERT INTO salary VALUES ("Level3",5000.00); 1 row created. SQL> INSERT INTO salary VALUES ("Level4",6000.00); 1 row created. SQL> SQL> select * from emps;
EMP
TITLE
Tom Programmer Jack Tester Mary Technician
3 rows selected. SQL> select * from JobLevel;
TITLE
RANK
Programmer Level1 Tester Level2 Technician Level3 3 rows selected. SQL> select * from salary;
RANK PAYMENT
----------
Level1 2000 Level2 3000 Level3 5000 Level4 6000 4 rows selected. SQL> SQL> SQL> SELECT salary.rank
2 FROM salary LEFT OUTER JOIN JobLevel ON (salary.rank = JobLevel.rank) 3 WHERE JobLevel.rank IS NULL;
RANK
Level4
1 row selected. SQL> SQL> SQL> DROP TABLE emps; Table dropped. SQL> DROP TABLE JobLevel; Table dropped. SQL> DROP TABLE salary; Table dropped. SQL> SQL>
</source>
LEFT OUTER JOIN vs RIGHT OUTER JOIN
<source lang="sql">
SQL> SQL> CREATE TABLE project (
2 pro_id NUMBER(4), 3 pro_name VARCHAR2(40), 4 budget NUMBER(9,2), 5 CONSTRAINT project_pk PRIMARY KEY (pro_id) 6 );
Table created. SQL> SQL> SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1001, "A",12345); 1 row created. SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1002, "ERP",23456); 1 row created. SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1003, "SQL",34567); 1 row created. SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1004, "CRM",45678); 1 row created. SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1005, "VPN",56789); 1 row created. SQL> SQL> SQL> SQL> CREATE TABLE server_usage (
2 pro_id NUMBER(4), 3 emp_id NUMBER, 4 time_log_date DATE, 5 hours_logged NUMBER(8,2), 6 dollars_charged NUMBER(8,2), 7 CONSTRAINT server_usage_pk PRIMARY KEY (pro_id, emp_id, time_log_date) 8 );
Table created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1001,101,to_date("4-Apr-2004","dd-mon-yyyy"),1123,222);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1002,102,to_date("4-Apr-2005","dd-mon-yyyy"),1124,223);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1003,103,to_date("4-Apr-2006","dd-mon-yyyy"),1125,224);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1004,104,to_date("4-Apr-2007","dd-mon-yyyy"),1126,225);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1005,105,to_date("4-Apr-2008","dd-mon-yyyy"),1127,226);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1001,106,to_date("4-Apr-2009","dd-mon-yyyy"),1128,227);
1 row created. SQL> INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
2 VALUES (1002,107,to_date("4-Apr-2010","dd-mon-yyyy"),1129,228);
1 row created. SQL> SQL> SQL> SET ECHO ON SQL> SELECT p.pro_name, ph.time_log_date, ph.hours_logged
2 FROM project p LEFT OUTER JOIN server_usage ph 3 ON p.pro_id = ph.pro_id;
A 04-APR-04 1123 ERP 04-APR-05 1124 SQL 04-APR-06 1125 CRM 04-APR-07 1126 VPN 04-APR-08 1127 A 04-APR-09 1128 ERP 04-APR-10 1129
7 rows selected. SQL> SQL> SELECT p.pro_name, ph.time_log_date, ph.hours_logged
2 FROM server_usage ph RIGHT OUTER JOIN project p 3 ON p.pro_id = ph.pro_id;
A 04-APR-04 1123 ERP 04-APR-05 1124 SQL 04-APR-06 1125 CRM 04-APR-07 1126 VPN 04-APR-08 1127 A 04-APR-09 1128 ERP 04-APR-10 1129
7 rows selected. SQL> SQL> drop table server_usage; Table dropped. SQL> drop table project; Table dropped.
</source>
