所谓的笛卡儿积所生成的表，就是一个基本表中每一行与另一个基本表中的每一行连接在一起所生成的表，查询结果的行数是两个基本表的行数的积。
SQL> select * from emp,dept; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO DEPTNO DNAME LOC ------ --------- --------- ----- ---------- ------ ----- ------ ------ ------------ ------------- 7369 SMITH CLERK 7902 17-12月-80 800 20 10 ACCOUNTING NEW YORK 7499 ALLEN SALESMAN 7698 20-2月 -81 1600 300 30 10 ACCOUNTING NEW YORK 7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30 10 ACCOUNTING NEW YORK 7566 JONES MANAGER 7839 02-4月 -81 2975 20 10 ACCOUNTING NEW YORK 7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30 10 ACCOUNTING NEW YORK 7698 BLAKE MANAGER 7839 01-5月 -81 2850 30 10 ACCOUNTING NEW YORK 7782 CLARK MANAGER 7839 09-6月 -81 2450 10 10 ACCOUNTING NEW YORK 7788 SCOTT ANALYST 7566 24-1月 -87 3000 20 10 ACCOUNTING NEW YORK 7839 KING PRESIDENT 17-11月-81 5000 10 10 ACCOUNTING NEW YORK 7844 TURNER SALESMAN 7698 08-9月 -81 1500 0 30 10 ACCOUNTING NEW YORK 7876 ADAMS CLERK 7788 02-4月 -87 1100 20 10 ACCOUNTING NEW YORK 7900 JAMES CLERK 7698 03-12月-81 1800 30 10 ACCOUNTING NEW YORK 7902 FORD ANALYST 7566 03-12月-81 3000 20 10 ACCOUNTING NEW YORK 7934 MILLER CLERK 7782 23-1月 -82 1300 10 10 ACCOUNTING NEW YORK 7935 XIAOXUE MANAGER 7839 01-3月 -98 5000 500 20 10 ACCOUNTING NEW YORK 7369 SMITH CLERK 7902 17-12月-80 800 20 20 RESEARCH DALLAS 7499 ALLEN SALESMAN 7698 20-2月 -81 1600 300 30 20 RESEARCH DALLAS 7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30 20 RESEARCH DALLAS 7566 JONES MANAGER 7839 02-4月 -81 2975 20 20 RESEARCH DALLAS 7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30 20 RESEARCH DALLAS 7698 BLAKE MANAGER 7839 01-5月 -81 2850 30 20 RESEARCH DALLAS 7782 CLARK MANAGER 7839 09-6月 -81 2450 10 20 RESEARCH DALLAS 7788 SCOTT ANALYST 7566 24-1月 -87 3000 20 20 RESEARCH DALLAS 7839 KING PRESIDENT 17-11月-81 5000 10 20 RESEARCH DALLAS 7844 TURNER SALESMAN 7698 08-9月 -81 1500 0 30 20 RESEARCH DALLAS 7876 ADAMS CLERK 7788 02-4月 -87 1100 20 20 RESEARCH DALLAS 7900 JAMES CLERK 7698 03-12月-81 1800 30 20 RESEARCH DALLAS 7902 FORD ANALYST 7566 03-12月-81 3000 20 20 RESEARCH DALLAS 7934 MILLER CLERK 7782 23-1月 -82 1300 10 20 RESEARCH DALLAS 7935 XIAOXUE MANAGER 7839 01-3月 -98 5000 500 20 20 RESEARCH DALLAS 7369 SMITH CLERK 7902 17-12月-80 800 20 30 SALES CHICAGO 7499 ALLEN SALESMAN 7698 20-2月 -81 1600 300 30 30 SALES CHICAGO 7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30 30 SALES CHICAGO 7566 JONES MANAGER 7839 02-4月 -81 2975 20 30 SALES CHICAGO 7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30 30 SALES CHICAGO 7698 BLAKE MANAGER 7839 01-5月 -81 2850 30 30 SALES CHICAGO 7782 CLARK MANAGER 7839 09-6月 -81 2450 10 30 SALES CHICAGO 7788 SCOTT ANALYST 7566 24-1月 -87 3000 20 30 SALES CHICAGO 7839 KING PRESIDENT 17-11月-81 5000 10 30 SALES CHICAGO 7844 TURNER SALESMAN 7698 08-9月 -81 1500 0 30 30 SALES CHICAGO 7876 ADAMS CLERK 7788 02-4月 -87 1100 20 30 SALES CHICAGO 7900 JAMES CLERK 7698 03-12月-81 1800 30 30 SALES CHICAGO 7902 FORD ANALYST 7566 03-12月-81 3000 20 30 SALES CHICAGO 7934 MILLER CLERK 7782 23-1月 -82 1300 10 30 SALES CHICAGO 7935 XIAOXUE MANAGER 7839 01-3月 -98 5000 500 20 30 SALES CHICAGO 7369 SMITH CLERK 7902 17-12月-80 800 20 40 OPERATIONS BOSTON 7499 ALLEN SALESMAN 7698 20-2月 -81 1600 300 30 40 OPERATIONS BOSTON 7521 WARD SALESMAN 7698 22-2月 -81 1250 500 30 40 OPERATIONS BOSTON 7566 JONES MANAGER 7839 02-4月 -81 2975 20 40 OPERATIONS BOSTON 7654 MARTIN SALESMAN 7698 28-9月 -81 1250 1400 30 40 OPERATIO