Any function in DB2 to help

[heming_g]

to help to Replace the stupid Coding like
SUBSTR('0000',LENGTH('22'),4-LENGTH('22'))||'22'
changing string '22' to '0022' ???

[Knut Stolze]

he******@hotmail.com wrote:

to help to Replace the stupid Coding like
SUBSTR('0000',LENGTH('22'),4-LENGTH('22'))||'22'
changing string '22' to '0022' ???

That is really stupid and slow coding. I would replace it if I had the
chance.

--
Knut Stolze
DB2 Information Integration Development
IBM Germany

[Tonkuma]

Some ideas:
SUBSTR('000'||'22',LENGTH('22'))

SUBSTR(RIGHT('0000'||'22',4),1,4)

DIGITS(DECIMAL('22',4,0))

[Knut Stolze]

Tonkuma wrote:

Some ideas:
SUBSTR('000'||'22',LENGTH('22'))

SUBSTR(RIGHT('0000'||'22',4),1,4)

DIGITS(DECIMAL('22',4,0))

I assumed that the given expression actually consisted of constants only.
So there would be no need to do the calculation on the constants but rather
write the results there directly.

--
Knut Stolze
DB2 Information Integration Development
IBM Germany

[Brian Tkatch]

To make that itself shorter:

REPEAT('0', 4 - LENGTH('22')) || '22'

B.

[Bob Stearns]

Brian Tkatch wrote:

To make that itself shorter:

REPEAT('0', 4 - LENGTH('22')) || '22'

B.

Which is not quite the best you can do if the '22' in the example really
stands for a CHARACTER expression. RIGHT('0000'||'22',4) is, I think,
the best in the case of a CHARACTER expression.

Under the presumption that the '22' in the example really stands for an
integer expression, a more general solution is RIGHT(CHAR(10000+22),4).
The 10000 and the 4 in the expression can be adjusted trivially for any
reasonable number of leading zeroes. This is optimal in that it requires
only one evaluation of the expression. Negative numbers, decimal
expressions, etc. are left as an exercise for the interested reader :-)

[Tonkuma]

REPEAT and RIGHT are SYSFUN schema, and returns VARCHAR(4000).
This fact sometime make things problematic or troublesome.
For example, if you use CLP or Command Editor, a long column appears in
the result.
------------------------- Commands Entered -------------------------
VALUES REPEAT('0', 4 - LENGTH('22')) || '22';
-------------------------------------------------------------------

1





































--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0022






































1 record(s) selected.
So, I enclosed those expressions by SUBSTR. Like following.

------------------------ Commands Entered -------------------------
VALUES SUBSTR(RIGHT('0000'||'22',4),1,4);
-------------------------------------------------------------------
VALUES SUBSTR(RIGHT('0000'||'22',4),1,4)

1
----
0022

1 record(s) selected.

[heming_g]

ah.. i quite agree with you , and i write a function to do that

-----------------------------

CREATE FUNCTION F_FILLSTR(V_TAR VARCHAR(256),V_CNT INTEGER )
RETURNS VARCHAR(512)
LANGUAGE SQL
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE COMSTR VARCHAR(256);
SET COMSTR = SPACE(V_CNT);
SET COMSTR = REPLACE(COMSTR,' ','0');
SET COMSTR = COMSTR||RTRIM(V_TAR);
SET COMSTR = RIGHT(COMSTR,V_CNT);
RETURN COMSTR;
END@

-----------------------------

run "values f_fillstr('aa',8)" : result 000000aa

then i make a more general one and compile it successfully , but when i
runs , a trouble
comes , saying "SQL0440N No authorized routine name F_FILLSTR .... "

-----------------------------

CREATE FUNCTION F_FILLSTR(V_TAR VARCHAR(256),V_SUSTR CHAR(1),V_CNT
INTEGER )
RETURNS VARCHAR(512)
LANGUAGE SQL
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE COMSTR VARCHAR(256);
SET COMSTR = SPACE(V_CNT);
SET COMSTR = REPLACE(COMSTR,' ',V_SUSTR);
SET COMSTR = COMSTR||RTRIM(V_TAR);
SET COMSTR = RIGHT(COMSTR,V_CNT);
RETURN COMSTR;
END@

-----------------------------

any help again ?? thx a lot .

[heming_g]

ah.. i quite agree with you , and i write a function to do that .

-----------------------------

CREATE FUNCTION F_FILLSTR(V_TAR VARCHAR(256),V_CNT INTEGER )
RETURNS VARCHAR(512)
LANGUAGE SQL
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE COMSTR VARCHAR(256);
SET COMSTR = SPACE(V_CNT);
SET COMSTR = REPLACE(COMSTR,' ','0');
SET COMSTR = COMSTR||RTRIM(V_TAR);
SET COMSTR = RIGHT(COMSTR,V_CNT);
RETURN COMSTR;
END@

-----------------------------
run "values f_fillstr('aa',8)" : result 000000aa
then i make a more general one and compile it successfully , but when i
runs , a trouble
comes , saying "SQL0440N No authorized routine name F_FILLSTR .... "

-----------------------------

CREATE FUNCTION F_FILLSTR(V_TAR VARCHAR(256),V_SUSTR CHAR(1),V_CNT
INTEGER )
RETURNS VARCHAR(512)
LANGUAGE SQL
NO EXTERNAL ACTION
BEGIN ATOMIC
DECLARE COMSTR VARCHAR(256);
SET COMSTR = SPACE(V_CNT);
SET COMSTR = REPLACE(COMSTR,' ',V_SUSTR);
SET COMSTR = COMSTR||RTRIM(V_TAR);
SET COMSTR = RIGHT(COMSTR,V_CNT);
RETURN COMSTR;
END@

-----------------------------

any help again ?? thx a lot .

[Tonkuma]

My guess is that you use the function like F_FILLSTR('aa', 'x', 8).
If so, V_SUSTR CHAR(1) is the root of problem.
Try V_SUSTR VARCHAR(1).
Because data type of string constant(for example 'x') is VARCHAR.

[Brian Tkatch]

>Which is not quite the best you can do if the '22' in the example really

stands for a CHARACTER expression. RIGHT('0000'||'22',4) is, I think,
the best in the case of a CHARACTER expression.

Mostly, i was reponding how to keep the current logic there, so i used
REPEAT instead of SUBSTR.

For myself, i agree i would use RIGHT('0000'||'22',4), because it makes
more sense to me. But, exactly why do you think it best? Just because
its straight forward? Or is there something i am missing?

B.

[Brian Tkatch]

Yeah, i know, the CLP is my main environment. :)

But inside a script, it shouldn't matter much, as the declaration of
the variable should handle it. (Unless of course, he's using a version
7 Windows client to connect via ODBC to a version 8 Solaris server, in
which case a SUBSTR would crash the server when the last parameter was
out of range. :) )

B.

[Bob Stearns]

Brian Tkatch wrote:

Which is not quite the best you can do if the '22' in the example really
stands for a CHARACTER expression. RIGHT('0000'||'22',4) is, I think,
the best in the case of a CHARACTER expression.

Mostly, i was reponding how to keep the current logic there, so i used
REPEAT instead of SUBSTR.

For myself, i agree i would use RIGHT('0000'||'22',4), because it makes
more sense to me. But, exactly why do you think it best? Just because
its straight forward? Or is there something i am missing?

B.

Single evaluation of the parameter '22'. It makes no sense if it is a
constant, no difference if it is a single column, but it could be very
important if it were a complex expression in its own right. Good coding
practice, even in the simple cases, will lead to better results in the
harder ones.

[Brian Tkatch]

Good point. Thanx.

B.