I am trying to create a function in SQL server that takes a column name as a parameter this column contains first names of people, I manually inserted these names. Any name that contains a special character such as ' as in O'Brian I inserted the value as O$6Brian the $6 representing ' . The same for Jack & Jill the & I inserted as $7 so in the database this looks like Jack $7 Jill.
so when someone passes the name of the Names column which in my case is called fname into the function I would like the function to replace the $6 and $7 with the appropriate character.
I know this can be done using in the front end app but I just want to learn some more SQL hence why I am asking I have the following so far which does not work.
create function fn_convertDBChars(#stringtoconvert nvarchar)
returns nvarchar(20)
as
begin
declare #Return nvarchar(20)
select
#Return = case #stringtoconvert
when '$6' then REPLACE(#stringtoconvert, '$7', '&')
end
return #Return
end;
I would be grateful for any advice.
You were correct with most part of your function, except you should be using LIKE operator to match the patterns. You can replace $6 with single-quotes and $7 with & symbol in a user-defined function like this. Of course, you would be using the REPLACE function internally. Here is what your function would look like.
create function fn_convertDBChars(#stringtoconvert NVARCHAR(20))
returns nvarchar(20)
as
begin
declare #Return nvarchar(20)
select #Return = CASE WHEN #stringtoconvert LIKE '%$6%' then REPLACE(#stringtoconvert, '$6', '''')
WHEN #stringtoconvert LIKE '%$7%' THEN REPLACE(#stringtoconvert,'$7','&')
ELSE #stringtoconvert END
return #Return
end;
SELECT dbo.fn_convertDBChars('Jack $7 Jill') -- Returns Jack & Jill
SELECT dbo.fn_convertDBChars('O''Brian') -- Returns O'Brian
SELECT dbo.fn_convertDBChars(fname) from dbo.table_name -- This is how you would call your function on the column.
Notice the escape character used here to escape single-quotes. You can escape that by using two occurrences of single-quotes.
Just use the built-in function REPLACE like below:
set #Return = REPLACE(#stringtoconvert, '$7', '&')
where #stringtoconvert like '%$7%'
Related
I want to check if a variable's value is LIKE few other values (similar to SQL's LIKE operator). For example, I was hoping the below would print valid. But it doesn't. Are wildcards allowed in the list of values being compared?
declare #var nvarchar(50) = 'SPARK'
IF (UPPER(TRIM(#var)) NOT IN ('%SQL%', '%SERVER%', '%PAR%'))
print('invalid')
else
print('valid')
You can't use wildcards in an IN clause. NOT IN ('%SQL%', '%SERVER%', '%PAR%') would check if the value is literally one of those values, so your value 'SPARK' would not match the last value, '%PAR%'. Effectively a NOT IN is parsed in the background like so:
#VAR != '%SQL%' AND #VAR != '%SERVER%' AND #VAR != '%PAR%'
This is why NULL values give "unexpected" results in a NOT IN, as != NULL results in UNKNOWN, and thus the clause resolves to UNKNOWN, which not TRUE.
One work around, however, is to use an EXISTS (or in this case, a NOT EXISTS):
DECLARE #var nvarchar(50) = N'SPARK';
IF NOT EXISTS (SELECT 1 FROM(VALUES(N'SQL'),(N'SERVER'),(N'PAR'))V(S) WHERE #VAR LIKE CONCAT(N'%',V.S,N'%'))
PRINT('invalid');
ELSE
PRINT('valid');
I'm kinda new into pgplsql and so far I have to create a function that loops an array that is received as a function.
The main idea of the function is to insert new records into a table that maps each id contained in the array received with a new formatted id, the format depends on the second parameter received and return the table "idsTable".
The problem is that when I try to create the function it sends me an error:
ERROR: loop variable of FOREACH must be a known variable or list of variables
LINE 38: FOREACH objectid IN ARRAY idsList LOOP
I'm not sure if I have to declare the objectid variable cause in the examples that I have seen they didn't.
So far I have this:
CREATE OR REPLACE FUNCTION createId(idsList varchar[], objectType varchar)
RETURNS TABLE(original_id varchar, new_id char) as
$$
BEGIN
IF LOWER(objectType) = 'global' THEN
FOREACH objectid IN ARRAY idsList LOOP
INSERT INTO idsTable(original_id, new_id)
VALUES(objectid, 'GID'||nextval('mapSquema.globalid')::TEXT);
END LOOP;
ELSE
FOREACH objectid IN ARRAY idsList LOOP
INSERT INTO idsTable(original_id, new_id)
VALUES(objectid, 'ORG'||nextval('mapSquema.globalid')::TEXT);
END LOOP;
END IF;
END;
$$ LANGUAGE plpgsql;
Any ideas of what could be wrong?
edit: I haven't add the part where the idsTable is returned.
Unrelated, but: you don't really need a loop for that. And you can simplify the function by only writing the INSERT once. You also forgot to return something from your function. As it is declared as returns table that is required:
CREATE OR REPLACE FUNCTION createid(idslist varchar[], objecttype varchar)
RETURNS TABLE(original_id varchar, new_id varchar) as
$$
declare
l_prefix text;
BEGIN
IF LOWER(objectType) = 'global' THEN
l_prefix := 'GID';
ELSE
l_prefix := 'ORG';
END IF;
RETURN QUERY --<< return the result of the insert
INSERT INTO idstable(original_id, new_id)
select t.x, l_prefix||nextval('mapSquema.globalid')::TEXT
from unnest(idslist) as t(x)
returning *
END;
$$ LANGUAGE plpgsql;
ALL
I have a postgresql function,so this:
CREATE OR REPLACE FUNCTION query_callouts(
INOUT io_cursor_ref refcursor,
INOUT opstatus integer,
INOUT errtext character varying)
RETURNS record AS
$BODY$
DECLARE
BEGIN
OPEN $1 FOR
SELECT tablename FROM pg_tables limit 10;
--SELECT * from call_out_numbers;
RETURN;
Exception
When Others Then
GET STACKED DIAGNOSTICS opstatus = RETURNED_SQLSTATE,
errText = MESSAGE_TEXT;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION query_callouts(refcursor, integer, character varying)
OWNER TO postgres;
I want to known ,how to use libpq in my c codes to visit the function - query_callouts and get the param io_cursor_ref and opstatus and errtext?
You can call the function just like you are executing any query:
select * from query_callouts('mycur', 0, '');
io_cursor_ref | opstatus | errtext
---------------+----------+---------
mycur | 0 |
(1 row)
opstatus and errtext would be set to the appropriate values if an exception occurs.
io_cursor_ref contains the name you have passed to the function.
Internally, a refcursor value is simply the string name of a so-called
portal containing the active query for the cursor. This name can be
passed around, assigned to other refcursor variables, and so on,
without disturbing the portal.
Note, you can use a refcursor only within a transaction.
All portals are implicitly closed at transaction end. Therefore a
refcursor value is usable to reference an open cursor only until the
end of the transaction.
You can use explicit transaction:
begin;
select * from query_callouts('mycur', 0, '');
fetch all in mycur;
-- save or show the query result
-- and finally
commit;
or use mycur inside a function.
The quotes are from the documentation.
It's just like any other query.
SELECT * FROM query_callouts('cursorname', 4, 'msg')
I suspect some if not all of your parameters should be OUT parameters not INOUT parameters, though. You don't ever use the input value of errtext at least.
I want to use array(which is passed to function) under Where in clause
Here is what i tried
First created the array type
create or replace type p_emp_arr as table of number
Function is
create or replace
FUNCTION getEmployee_func ( empId_arr IN p_emp_arr)
RETURN number IS
total number(2) := 0;
BEGIN
IF(empId_arr is null)
THEN
empIdClause := '';
ELSE
empIdClause := 'AND Employee.empId in (select column_value from table('||empId_arr||'))';
END IF;
....
RETURN total;
END;
But gives error
Error(17,23): PLS-00306: wrong number or types of arguments in call to '||'
The error is because CONCAT (||) operator accepts only scalar variables (string/number), you cannot pass an array to it.
You need to execute this as a dynamic PL/SQL block.
In case you want to bind the array dynamically, try something like this.
Bind the variables using IN and OUT keywords appropriately.
In your Anonymous block string, prefix the to-be-bind variables with colon (:)
EXECUTE IMMEDIATE '
BEGIN
SELECT
COLUM1,COLUMN2..
INTO
:VAR1, :VAR2..
FROM .... WHERE...
AND Employee.empId in (select column_value from table(:empId_arr));
END;
'
USING OUT VAR1, OUT VAR2... IN empId_arr;
It can also be Simply,
OPEN EMP_CURSOR FOR
'SELECT * FROM Employee
where empId in SELECT COLUMN_VALUE FROM TABLE(:empId_arr)'
USING empId_arr ;
If you take the output as a cursor;
AS Wernfried mentioned.. Using MEMBER OF operator.
OPEN EMP_CURSOR FOR
'SELECT * FROM Employee
where empId member of :empId_arr'
USING empId_arr ;
i am using a stored procedure, where it is taking policy number as parameter which is varchar. I need to eliminate the last 4 characters of the policy number when we retrive from the tables. But the data for policy numbers is not consistent, so I am confused how to use the logic for this. The sample policy numbers are:
KSDRE0021-000
APDRE-10-21-000
KSDRE0021
APDRE-10-21
These are four formats where policies are there in our tables.For some policies there is no tailing end '-000', so that is the challenging part. Now, I need to eliminate the tailing part '-000' from the policies when I retrieve the data from tables.
This is the sample code, which is pulling the policy data from tables.
Create Proc usp.dbo.policydataSP #policy_num varchar(18)
AS
Begin
Select * from policy_table pt
where pt.policy_num = #policy_num
End
STEP 1: Create a User Defined Function to normalize a policy number.
create function dbo.normalize_policy_num
(#policy_num varchar(100))
returns varchar(100)
as
begin
-- replace trailing digits
if (#policy_num like '%-[0-9][0-9][0-9]')
set #policy_num = left(#policy_num, len(#policy_num) - 4)
-- replace remaining hyphens
set #policy_num = replace(#policy_num, '-', '')
return #policy_num
end
What this essentially doing is stripping off the trailing '-000' from policy numbers that contain the pattern, then removing remaining hyphens. This function seems to work on your supplied policy numbers:
-- returns: KSDRE0021
select dbo.normalize_policy_num('KSDRE0021-000')
-- returns: APDRE1021
select dbo.normalize_policy_num('APDRE-10-21-000')
-- returns: KSDRE0021
select dbo.normalize_policy_num('KSDRE0021')
-- returns: APDRE1021
select dbo.normalize_policy_num('APDRE-10-21')
STEP 2: Modify your SP as follows:
create proc usp.dbo.policydataSP
#policy_num varchar(18)
as
begin
select
dbo.normalize_policy_num(pt.policy_num) as normalized_policy_num,
pt.*
from policy_table pt
where dbo.normalize_policy_num(#policy_num) = dbo.normalize_policy_num(pt.policy_num)
Note: If you are able to modify the table schema, you could add a persisted computed column using the UDF specified above. If you add an index to it, queries will run much faster. However, there will be some penalty for inserts, so there is a trade-off.
this is probably your best bet. Match the policy number up to the length of the requested parameter:
Create Proc usp.dbo.policydataSP
#policy_num varchar(18)
AS
Begin
Select * from policy_table pt where LEFT(len(#policy_num),pt.policy_num) = #policy_num
End
If you only want to strip -000 when returning results:
select case right(policy_num, 4)
when '-000' then left(policy_num, len(policy_num) - 4)
else policy_num end as policy_num
from policy_table pt
where pt.policy_num = #policy_num
If you want to strip any 3-digit value following a dash:
select case when policy_num like '%-[0-9][0-9][0-9]' then left(policy_num, len(policy_num) - 4)
else policy_num end as policy_num
from policy_table pt
where pt.policy_num = #policy_num