Re: [SQL] Question on pgpsql function

On Sunday 08 April 2007 12:47 pm, Karthikeyan Sundaram wrote:
> Hi Everybody,
>
> I am using Postgres 8.1.0 and I have a requirement.
>
> I have a table
>
> create table weekly_tbl (id int, week_flag bit(7) not null default
> '1111111');
>
> I want to create a function like this
>
> create function week_func (int) returns weekly_tbl as
> $$
> select id,
> substr(week_flag,1,1) as monday_flag,
> substr(week_flag,2,1) as tuesday_flag,
> substr(week_flag,3,1) as wednesday_flag,
> substr(week_flag,4,1) as thursday_flag,
> substr(week_flag,5,1) as friday_flag,
> substr(week_flag,6,1) as saturday_flag,
> substr(week_flag,7,1) as sunday_flag
> from weekly_tbl where id=$1;
> $$
> language SQL;
>
> I am getting an error message
> ERROR: function substr(bit, integer, integer) does not existHINT: No
> function matches the given name and argument types. You may need to add
> explicit type casts.CONTEXT: SQL function "week_func"
>
> I know I can do this in view. But for a purpose, I don't want to do it in
> view. Can somebody help me?
>
> Regards
> skarthi

The problem is with your use of the substr() function. You are passing it a
field of type bit (week_flag) where the function needs a text type. See the
documentation for bit functions-
http://www.postgresql.org/docs/8.2/interactive/functions-bitstring.html
There are some bit compatible string functions mentioned.

--
Adrian Klaver
aklaver(at)comcast(dot)net