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1、创建测试表；

create table test_col_1(id number, var varchar2(200));

create table test_col_2(id number, var varchar2(200));

2、插入测试数据，

insert into test_col_1

select level*8, 'var'||32313133353236313431303231363533e59b9ee7ad9431333431373839level*8 from dual connect by level <= 20;

insert into test_col_2

select level, 'var'||level from dual connect by level <= 100;

3、比较两表的数据，可以发现表2的数据多于表1；

select 'test_col_1' tbl_name, count(*) from test_col_1 t

union all

select 'test_col_2' tbl_n