CREATE OR REPLACE FUNCTION evaluation (a DATE,m Number)
RETURN VARCHAR2
IS
BEGIN
RETURN CASE
WHEN (floor(sysdate - a) < m) THEN 'Yes'
ELSE 'No'
END;
Am i doing wrongly, when executing the following code if shows me an error like:
Error: ORA-01722: invalid number
The posted code is missing an END; (the first END ends the CASE, so a second is needed to end the procedure), but other than that it is working, provided you enter a number and not a string that cannot be converted to a number.
select evaluation(sysdate+3, 2) from dual;
YES
select evaluation(sysdate+3, '2') from dual;
YES
select evaluation(sysdate+3, 'a') from dual;
Error: ORA-01722: invalid number
Include another end # last.....
CREATE OR REPLACE FUNCTION evaluation (a DATE,m Number)
RETURN VARCHAR2
IS
BEGIN
RETURN (CASE
WHEN (floor(sysdate - a) < m) THEN 'Yes'
ELSE 'No'
END);
END;
Related
I can't use boolean in a sql query.
Therefore I can't create a function that return true or false and use it to test a condition.
I must create a function that return something (1 for instance) and test it. Like that:
WITH
FUNCTION f (input INTEGER)
RETURN INTEGER
IS
BEGIN
RETURN CASE WHEN input = 1 THEN 1 ELSE 0 END;
END;
A AS (SELECT 1 a FROM DUAL)
SELECT *
FROM a
WHERE f(a.a) = 1
instead of that:
WITH
FUNCTION f (input INTEGER)
RETURN boolean
IS
BEGIN
RETURN input = 1 ;
END;
A AS (SELECT 1 a FROM DUAL)
SELECT *
FROM a
WHERE f(a.a)
Unless there is another way?
code
I've tried to use a macro but to no avail
WITH
FUNCTION ft
RETURN VARCHAR2 SQL_MACRO
IS
BEGIN
RETURN q'{
SELECT 1
FROM dual
}';
END;
FUNCTION fc
RETURN VARCHAR2 SQL_MACRO
IS
BEGIN
RETURN q'{
1=1
}';
END;
SELECT *
FROM ft()
WHERE fc()
ORA-00920: invalid relational operator
code
The BOOLEAN data type is a PL/SQL only data type and is not supported in Oracle SQL statements.
Use two constants:
0 for false, 1 (or non-zero) for true (as per the C language).
0 for no errors, non-zero for errors (as per Unix program exit codes).
'Y' for yes, 'N' for no.
'success' and 'failure'
etc.
Whatever you return is your personal preference. Document the convention you are going to use and then use it consistently so that everyone on the same project uses the same convention.
Unless there is another way?
No, just pick a convention for truthy/falsy values and stick to that.
WITH
FUNCTION f_check_int ( p_str VARCHAR2 )
RETURN VARCHAR2 ------- Y / N
IS
lv_data NUMBER;
BEGIN
lv_data := TO_NUMBER(p_str);
IF lv_data>0 AND MOD(lv_data,1)=0 THEN
RETURN 'Y';
ELSE
RETURN 'N';
END IF;
EXCEPTION
WHEN VALUE_ERROR THEN
RETURN 'N';
END;
A AS (SELECT 1 a FROM DUAL)
SELECT *
FROM a
WHERE f_check_int(a.a) = 'Y'
Is it possible to have constant function parameters in SQL to make sure the values are not changed later?
Something like this doesn't work:
function my_func(
first_param constant varchar2
, second_param constant varchar2
) return varchar2
is
... -- Rest
That is not necessary as you cannot redefine an IN parameter. For example:
CREATE FUNCTION does_not_work(
a IN NUMBER,
b IN NUMBER
) RETURN NUMBER
IS
BEGIN
IF a < 2 THEN
a := 2;
END IF;
RETURN GREATEST( a, b );
END;
/
(Note: the IN keyword is optional and the default parameter direction; you would get the same error if you declared the signature without the IN keywords.)
Gives:
ORA-24344: success with compilation error
If you look at the errors:
SELECT * FROM USER_ERRORS;
Outputs:
NAME
TYPE
SEQUENCE
LINE
POSITION
TEXT
ATTRIBUTE
MESSAGE_NUMBER
DOES_NOT_WORK
FUNCTION
1
8
5
PLS-00363: expression 'A' cannot be used as an assignment target
ERROR
363
DOES_NOT_WORK
FUNCTION
2
8
5
PL/SQL: Statement ignored
ERROR
0
This tells you that you can't use an IN parameter as an assignment target.
IN one of My Application. We have one query, where actully we are calling a function and function returns o/p as String. Any one have idea how to get substring from function returned o/p?
I am using like this
select substr(myfunction(),0,4000) from dual.
I am getting below issue.
ORA-06502: PL/SQL: numeric or value error: character string buffer too
small.
Please help me . Thanks in Advance.
Since you're applying a substr, presumably the value being returned by your function is greater than 4000 characters. If that's the case then you will get this error from SQL, you can't avoid it. It's trying to assign the long string value to an (implicit) SQL-level varchar2, which of course cannot be more than 4000 characters either, before passing that to the substr function.
You will have to add the substr to the return from your function, or if it is sometimes called from somewhere that can handle the long values, you can have a wrapper function that only returns the first 4000 characters - so you can have the appropriate value as needed.
To demonstrate with a dummy function to (inefficiently!) create a large string:
create or replace function myfunction(strlen number) return varchar2 is
str varchar2(32767) := 'X';
begin
while length(str) < least(strlen, 32767) loop
str := str || 'X';
end loop;
return str;
end myfunction;
/
This is fine because the function's output doesn't exceed the SQL varchar2 size:
select length(substr(myfunction(4000),0,4000)) from dual;
LENGTH(SUBSTR(MYFUNCTION(4000),0,4000))
---------------------------------------
4000
But this gets your error because the function's output is too long:
select length(substr(myfunction(4001),0,4000)) from dual;
SQL Error: ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at "STACKOVERFLOW.MYFUNCTION", line 7
06502. 00000 - "PL/SQL: numeric or value error%s"
With a simple wrapper function as a workaround:
create or replace function trunc_myfunction(strlen number) return varchar2 is
begin
return substr(myfunction(strlen), 0, 4000);
end;
/
select length(substr(trunc_myfunction(4000),0,4000)) from dual;
LENGTH(SUBSTR(TRUNC_MYFUNCTION(4000),0,4000))
---------------------------------------------
4000
select length(substr(trunc_myfunction(4001),0,4000)) from dual;
LENGTH(SUBSTR(TRUNC_MYFUNCTION(4001),0,4000))
---------------------------------------------
4000
select length(substr(trunc_myfunction(32767),0,4000)) from dual;
LENGTH(SUBSTR(TRUNC_MYFUNCTION(32767),0,4000))
----------------------------------------------
4000
Most probably you are trying to store more characters than is allowed in one of the variables that you use in your function. See: PL/SQL: numeric or value error: character string buffer too small %ROWTYPE
Simplest example:
DECLARE
v_varchar2_test VARCHAR2(5);
BEGIN
v_varchar2_test := '123456';
END;
And the error is, like in your case, ORA-06502.
Make sure that the value returned by the function is of the correct type;
I have just tried it like this:
create or replace
FUNCTION MONTH
(DATA IN DATE)
RETURN VARCHAR IS
BEGIN
RETURN TO_CHAR(DATA, 'MM');
END;
and the call:
SELECT substr(MONTH(SYSDATE),0,1) FROM DUAL;
and it worked.
In a SQL query on Oracle 10g, I need to determine whether a string is numeric or not. How can I do this?
You can use REGEXP_LIKE:
SELECT 1 FROM DUAL
WHERE REGEXP_LIKE('23.9', '^\d+(\.\d+)?$', '')
You ca try this:
SELECT LENGTH(TRIM(TRANSLATE(string1, ' +-.0123456789', ' '))) FROM DUAL
where string1 is what you're evaluating. It will return null if numeric. Look here for further clarification
I don't have access to a 10G instance for testing, but this works in 9i:
CREATE OR REPLACE FUNCTION is_numeric (p_val VARCHAR2)
RETURN NUMBER
IS
v_val NUMBER;
BEGIN
BEGIN
IF p_val IS NULL OR TRIM (p_val) = ''
THEN
RETURN 0;
END IF;
SELECT TO_NUMBER (p_val)
INTO v_val
FROM DUAL;
RETURN 1;
EXCEPTION
WHEN OTHERS
THEN
RETURN 0;
END;
END;
SELECT is_numeric ('333.5') is_numeric
FROM DUAL;
I have assumed you want nulls/empties treated as FALSE.
As pointed out by Tom Kyte in http://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:7466996200346537833, if you're using the built-in TO_NUMBER in a user defined function, you may need a bit of extra trickery to make it work.
FUNCTION is_number(x IN VARCHAR2)
RETURN NUMBER
IS
PROCEDURE check_number (y IN NUMBER)
IS
BEGIN
NULL;
END;
BEGIN
PRAGMA INLINE(check_number, 'No');
check_number(TO_NUMBER(x);
RETURN 1;
EXCEPTION
WHEN INVALID_NUMBER
THEN RETURN 0;
END is_number;
The problem is that the optimizing compiler may recognize that the result of the TO_NUMBER is not used anywhere and optimize it away.
Says Tom (his example was about dates rather then numbers):
the disabling of function inlining will make it do the call to
check_date HAS to be made as a function call - making it so that the
DATE has to be pushed onto the call stack. There is no chance for the
optimizing compiler to remove the call to to_date in this case. If the
call to to_date needed for the call to check_date fails for any
reason, we know that the string input was not convertible by that date
format.
Here is a method to determine numeric that can be part of a simple query, without creating a function. Accounts for embedded spaces, +- not the first character, or a second decimal point.
var v_test varchar2(20);
EXEC :v_test := ' -24.9 ';
select
(case when trim(:v_test) is null then 'N' ELSE -- only banks, or null
(case when instr(trim(:v_test),'+',2,1) > 0 then 'N' ELSE -- + sign not first char
(case when instr(trim(:v_test),'-',2,1) > 0 then 'N' ELSE -- - sign not first char
(case when instr(trim(:v_test),' ',1,1) > 0 then 'N' ELSE -- internal spaces
(case when instr(trim(:v_test),'.',1,2) > 0 then 'N' ELSE -- second decimal point
(case when LENGTH(TRIM(TRANSLATE(:v_test, ' +-.0123456789',' '))) is not null then 'N' ELSE -- only valid numeric charcters.
'Y'
END)END)END)END)END)END) as is_numeric
from dual;
I found that the solution
LENGTH(TRIM(TRANSLATE(string1, ' +-.0123456789', ' '))) is null
allows embedded blanks ... it accepts "123 45 6789" which for my purpose is not a number.
Another level of trim/translate corrects this. The following will detect a string field containing consecutive digits with leading or trailing blanks such that to_number(trim(string1)) will not fail
LENGTH(TRIM(TRANSLATE(translate(trim(string1),' ','X'), '0123456789', ' '))) is null
For integers you can use the below. The first translate changes spaces to be a character and the second changes numbers to be spaces. The Trim will then return null if only numbers exist.
TRIM(TRANSLATE(TRANSLATE(TRIM('1 2 3d 4'), ' ','#'),'0123456789',' ')) is null
Could you tell my why the following isnt working in postgres sql?:
See updated code below
UPDATE:
I expect the query to return "0.30" as float.
This construct is only for testing purposes, i have some complex querys which depend on this conditional structure... BUt i dont know how to fix it..
Result is:
ERROR: syntax error at or near "1"
LINE 4: if 1=1 then
UPDATE:
This construction appears in a function... so I want to do following:
CREATE FUNCTION f_test(myvalue integer) RETURNS float AS $$
BEGIN
select (
case (select '1')
when '1' then
if 1=1 then
0.30::float
else
0.50::float
end
else
1.00::float
end
);
END;
$$ LANGUAGE plpgsql;
select f_test(1) as test;
Error message see above.
There is no IF expr THEN result ELSE result END syntax for normal SQL queries in Postgres. As there is neither an IF() function as in MySQL, you have to use CASE:
select (
case (select '1')
when '1' then
case when 1=1 then 0.30::float else 0.50::float end
else
1.00::float
end
);
I don't know what you're trying to achieve with this function, but here's a working version.
CREATE FUNCTION f_test(myvalue integer) RETURNS float AS $$
BEGIN
IF myvalue = 1 THEN
IF 1=1 THEN
RETURN 0.30::FLOAT;
ELSE
RETURN 0.50::FLOAT;
END IF;
ELSE
RETURN 1.0::FLOAT;
END IF;
END;
The function returns 0.3 if input value is 1, otherwise it'll return 1. Edit: Note that 0.5 is never returned by the function.