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How to insert random character data into tables for testing purpose. THanks.

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How to insert random character data into tables for testing purpose. THanks.

leaf_yxj
Hi Guys, I want to insert the random character data into tables for testing purpose.
I created a table as follows :

create table test ( id int, b char(100));

I need to insert 100000 rows into this table. I know how to insert generate_series  into coloumn ID. But I don't how to insert the Random string data into column b.

Please help. Thanks. Grace
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Re: How to insert random character data into tables for testing purpose. THanks.

Andreas Kretschmer-2
leaf_yxj <[hidden email]> wrote:

> Hi Guys, I want to insert the random character data into tables for testing
> purpose.
> I created a table as follows :
>
> create table test ( id int, b char(100));
>
> I need to insert 100000 rows into this table. I know how to insert
> generate_series  into coloumn ID. But I don't how to insert the Random
> string data into column b.

something like:

test=# create table t_random as select s, md5(random()::text) from generate_Series(1,5) s;
SELECT 5
Time: 163,624 ms
test=*# select * from t_random ;
 s |               md5
---+----------------------------------
 1 | ef82dcb3e8465fa9a7494c569dfa093f
 2 | ad6ae62bb4a49c7889aba0bfcba224ff
 3 | 27717d30d8cf069b3129853d90ae5035
 4 | 530c200678711a414e000c60e73286bd
 5 | 2b2c3692da1b60760ff95d41cdf9b82d
(5 rows)



Andreas
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Re: How to insert random character data into tables for testing purpose. THanks.

leaf_yxj
Hi Andreas,

Thanks a lot.

I tried those following , they work.

1) insert into test values ( generate_series(1,100000000000), md5(random()::text));


2) create table t_random as select s, md5(random()::text) from generate_Series(1,5) s;

Thanks.
Regards.

Grace
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Re: How to insert random character data into tables for testing purpose. THanks.

Bruce Momjian
On Wed, May 02, 2012 at 11:03:47AM -0700, leaf_yxj wrote:

> Hi Andreas,
>
> Thanks a lot.
>
> I tried those following , they work.
>
> 1) insert into test values ( generate_series(1,100000000000),
> md5(random()::text));
>
>
> 2) create table t_random as select s, md5(random()::text) from
> generate_Series(1,5) s;

Here is a method that generates strings with a little more variability:

        SELECT
        (
                SELECT string_agg(x, '')
                FROM (
                        SELECT chr(ascii('A') + (random() * 25)::integer)
                        -- reference 'b' so it is correlated and re-evaluated
                        FROM generate_series(1, 40 + b * 0)
                ) AS y(x)
        )
        FROM generate_series(1,5) as a(b);
       
                        string_agg
        ------------------------------------------
         JWNRUIEPJQGDVBXDJDTROFSNMKGVNAQWWEORMSHV
         KNYGOWJXBEPOJICURIQGIIDFMRXYLFUUSTCIRLGR
         PVHXEITVQKBZREFEVDDHHYCASEIKPOCFJJDNRWJJ
         HKIYONDLQGSXFUXXZGHPUKUESXRLUATBLCAAPDLG
         JEENYCLYISODDIGWGXHBYCCJECJTFUAOYECXGNWO
        (5 rows)

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  + It's impossible for everything to be true. +

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Re: How to insert random character data into tables for testing purpose. THanks.

leaf_yxj
Hi Bruce,
 
Thanks. I tried. It works.
Regards.
 
Grace



At 2012-05-03 07:14:21,"Bruce Momjian" <[hidden email]> wrote: >On Wed, May 02, 2012 at 11:03:47AM -0700, leaf_yxj wrote: >> Hi Andreas, >>  >> Thanks a lot. >>  >> I tried those following , they work. >>  >> 1) insert into test values ( generate_series(1,100000000000), >> md5(random()::text)); >>  >>  >> 2) create table t_random as select s, md5(random()::text) from >> generate_Series(1,5) s; > >Here is a method that generates strings with a little more variability: > > SELECT >        ( >                SELECT string_agg(x, '') >                FROM ( >                        SELECT chr(ascii('A') + (random() * 25)::integer) > -- reference 'b' so it is correlated and re-evaluated >                        FROM generate_series(1, 40 + b * 0) >                ) AS y(x) >        ) > FROM generate_series(1,5) as a(b); > >                 string_agg > ------------------------------------------ >  JWNRUIEPJQGDVBXDJDTROFSNMKGVNAQWWEORMSHV >  KNYGOWJXBEPOJICURIQGIIDFMRXYLFUUSTCIRLGR >  PVHXEITVQKBZREFEVDDHHYCASEIKPOCFJJDNRWJJ >  HKIYONDLQGSXFUXXZGHPUKUESXRLUATBLCAAPDLG >  JEENYCLYISODDIGWGXHBYCCJECJTFUAOYECXGNWO > (5 rows) > >--  >  Bruce Momjian  <[hidden email]>        http://momjian.us >  EnterpriseDB                             http://enterprisedb.com > >  + It's impossible for everything to be true. +



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