Oracle用随机数据填充表

同样来自AskTom的脚本,可以对一个表填充随机数据 create or replace procedure gen_data( p_tname in varchar2, p_records in n

同样来自AskTom的脚本,可以对一个表填充随机数据

create or replace
procedure gen_data( p_tname in varchar2, p_records in number )
-- This routine is designed to be installed ONCE pre database, hence
-- the CURRENT_USER AUTHORIZATION.
authid current_user
as
l_insert long;
l_rows number default 0;
begin
-- dbms_random can be very cpu intensive. I use dbms_application_info
-- to instrument this routine, so I can monitor how far along it is
-- from another session. Every bulk insert will update v$session for us.
dbms_application_info.set_client_info( 'gen_data ' || p_tname );

-- The beginning of our insert into statement. Using a direct path
-- insert, if you alter your table to be nologging in an archive
-- log mode database, it'll generate no redo (assuming the table
-- is not indexed).
l_insert := 'insert /*+ append */ into ' || p_tname ||
' select ';

-- Now, we build the rest of our insert. We select the datatype
-- and size of each column. MAXVAL is used for numbers only. Using
-- the precision defined for the column, we determine the maximum number
-- that we can stuff in there.
for x in
( select data_type, data_length,
nvl(rpad( '9',data_precision,'9')/power(10,data_scale),9999999999) maxval
from user_tab_columns
where table_name = upper(p_tname)
order by column_id )
loop
-- If number, generate a number in the range 1 .. maxval.
if ( x.data_type in ('NUMBER', 'FLOAT' ))
then
l_insert := l_insert ||
'dbms_random.value(1,' || x.maxval || '),';

-- if a date/timestamp type, add some random number to sysdate.
elsif ( x.data_type = 'DATE' or x.data_type like 'TIMESTAMP%' )
then
l_insert := l_insert ||
'sysdate+dbms_random.value(1,1000),';

-- If a string, generate a random string between 1 and data length.
-- bytes in length
else
l_insert := l_insert || 'dbms_random.string(''A'',
trunc(dbms_random.value(1,' || x.data_length || '))),';
end if;
end loop;
l_insert := rtrim(l_insert,',') ||
' from all_objects where rownum <= :n';

-- Now, wo just execute the insert into as many times as needed
-- in order to put L_ROWS rows in the table. Since we are direct path
-- loading, we must commit after each insert. In this case, since
-- we are generating test data, it is OK from a transactional perspective.
-- And since this operation should generate little redo in all cases,
-- it will not affect our performance as well.
loop
execute immediate l_insert using p_records - l_rows;
l_rows := l_rows + sql%rowcount;
commit;
dbms_application_info.set_module
( l_rows || ' rows of ' || p_records, '' );
exit when ( l_rows >= p_records );
end loop;
end;
/

以Hr的depertment表为例,
SQL> create table dept as select * from departments where 1=0;

Table created.

但是需要注意的是 字段的取值范围不能小于1
以HR的employees表的COMMISSION_PCT字段为例,

执行到过程的第36行

最大值应该是0.99
但是实际执行的结果却是 超过了最大值,导致溢出。

解决这个问题,可以将下限设置为0

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