Oracle
create table TestTable as select lower(sys_guid()) AS guid, rownum as inc_id, trunc(dbms_random.value(0, 100)) as random_id, trunc(dbms_random.value()*power(10, 3), 8) as random_decimal1, trunc(dbms_random.value()*power(10, 8), 2) as random_decimal2, sysdate - 1 + rownum/24/3600 as inc_datetime, to_timestamp(systimestamp -1 + trunc(dbms_random.value(1, power(10, 8)))/24/3600) as random_timestamp, substr( dbms_random.string('x', 100), 0, trunc(dbms_random.value(10, 100))) as random_string, to_clob(dbms_random.string('x', power(10, 6))) as random_clob from dual connect by level <= 1000000;
PostgreSQL
SELECT gen_random_uuid() guid , 'user_' || (power(10, 7) + rowIndex) code , repeat('1',(random()*25)::integer) as name , rowIndex , (random()*100.)::numeric(4,2) random_decimal , TIMESTAMP '2022-01-01 00:00:00' + (TIMESTAMP '2022-12-31 23:59:59' - TIMESTAMP '2022-01-01 00:00:00') * random() AS random_timestamp FROM generate_series(1, 1000000) rowIndex;
SQL Server & MySQL
select floor(rand()*N) --FLOOR 函数返回小于或等于所给数字表达式的最大整数。
select ceiling(rand()*N) --CEILING 函数返回大于或等于所给数字表达式的最小整数。
循环 或借助其他表进行查询插入
参考资料：
https://blog.csdn.net/lizhangyong1989/article/details/45013509
https://blog.csdn.net/eagle89/article/details/116276102
https://www.cnblogs.com/terrence/p/4218741.html
https://www.jianshu.com/p/cf5d381ef637
https://www.cnblogs.com/CareySon/archive/2012/02/20/2359444.html