1、創建兩張測試表，

create table test_cj(name VARCHAR(20), remark varchar2(20));

create table test_kc(name VARCHAR(20), remark varchar2(20));

2、插入測試數據

insert into test_cj values('xh','cj_1');

insert into test_cj values('kcdh','cj_2');

insert into test_cj values('cj','cj_3');

insert into test_kc values('kcdh','kc_1');

insert into test_kc values('kcm','kc_2');

3、查詢兩張表的總記錄數，select t.*, rowid from test_cj t union all select t.*, rowid from test_kc t，

4、編寫sql，兩張表進行關聯，select t.name, t.remark, b.remark from test_cj t, test_kc b where t.name=b.name，可以發現關聯出kcdh的記錄，