I created an UDF in SQL Server but I want to check for null or invalid values. For example If Inserted an ID '333sd' I want my UDF to return a error message or print a message but in accordance to the documentation I have read the THROW or CATCH and TRY block cannot be used.
if object_id('dbo.fnDiscountPrice') is not null
drop function dbo.fnDiscountPrice;
go
create function fnDiscountPrice(#ItemID int)
returns money
as
begin
return (select sum(ItemPrice - DiscountAmount) as DiscountPrice
from OrderItems
where ItemID = #ItemID)
end
go
I have tried to declare a new variable and set it to 0 if It's null but If did it that way I will not express specifically the error. I want to be specific with that.
Related
I have to write a trigger for the tables I made and in insert update, I have to record a separate log table for those that are updated or inserted.
Columns in the log table will be like;
Done_process (will write update, insert)
Person (student number of the person treated)
Before (previous value for update, blank for insert)
After (new value for update, new value for insert)
This is my student_info table,
CREATE TABLE student_info (
school_id NUMBER,
id_no NUMBER NOT NULL UNIQUE,
name VARCHAR2(50) NOT NULL,
surname VARCHAR2(50) NOT NULL,
city VARCHAR2(50) NOT NULL,
birth_date DATE NOT NULL,
CONSTRAINT student_info_pk PRIMARY KEY(school_id )
);
CREATE TABLE og_log(
done_process VARCHAR2(30),
person VARCHAR2(30),
before VARCHAR2(30),
after VARCHAR2(30)
);
CREATE OR REPLACE TRIGGER og_trigger
BEFORE INSERT OR UPDATE OR DELETE ON student_info
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
ENABLE
DECLARE
BEGIN
IF INSERTING THEN
INSERT INTO og_log(done_process, person, before, after)
VALUES ('Insert',:new.school_id,:old.name,:new.name);
ELSIF UPDATING THEN
INSERT INTO og_log(done_process, person, before, after)
VALUES ('Update',:new.school_id,:old.name,:new.name);
END IF;
END;
/
When I try to run the code it gave an error as follows;
> Trıgger OG_TRIGGER created.
>
>
> Error starting at line : 280 in command - ELSIF UPDATING THEN Error
> report - Unknown Command
>
> SP2-0552: Bind variable "NEW" not declared.
>
> 0 rows inserted.
>
>
> Error starting at line : 283 in command - END IF Error report -
> Unknown Command
>
> SP2-0044: For a list of known commands enter HELP and to leave enter
> EXIT.
>
> Error starting at line : 284 in command - END Error report - Unknown
> Command
I believe you are creating this trigger for learning purpose and not something a real use case because what you do in trigger doesn't really making any sense.
The trigger you have mentioned is not compiling due to syntactical problems like where v_id := 20201033.
Where clause is used to compare the value and thus you should use = instead := which is an assignment operator.
Besides this problem few points which still needs to be taken care
Give a explicit convention for creating local variables. e.g. you have created a local variable v_id and the same column is also available in student_info table. Though it is not a problem in this case but it's good practice to keep the local variable specific like let's say l_v_id.
You have used a select statement inside trigger which could leads to NO_DATA_FOUND error and you should handle it by either in the exception section or another way would be using aggregate function like max() if obviously v_id is primary key. I doubt why you need this select statement ( you could use between old and new using something like coalesce(:old.school_id,:new_schoold_id) if I understood you) but I would leave it open to you to decide and act accordingly.
Considering above points final code will be,
CREATE OR REPLACE TRIGGER og_trigger
BEFORE INSERT OR UPDATE OR DELETE ON student_info
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
ENABLE
DECLARE
BEGIN
IF INSERTING THEN
INSERT INTO og_log(done_process, person, before, after)
VALUES ('Insert',:new.school_id,:old.city,:new.city);
ELSIF UPDATING THEN
INSERT INTO og_log(done_process, person, before, after)
VALUES ('Update',:new.school_id,:old.city,:new.city);
END IF;
END;
/
Find demo db<>fiddle
EDITED: Solving probably tool issue
I doubt the issue is with SQL Developer tool usage , however last try i would like to make,
Step1:
Drop both the tables used by issuing drop command
drop table STUDENT_INFO;
drop table og_log;
Step2:
Open another SQL worksheet using alt+F10 and do as I have shown in the following image. Please try and let me know.
We have a function that needs to select items from a linked server, like
Alter function dbo.ttest1()
returns int
as
begin
SELECT * FROM LINKED_SERVER.Database.Schema.Table
WHERE .....
RETURN 0
end
In case of the remote server is not available, the function will throw out the error saying connection failed, but I want to cover it and let it return a default value.
Since this is compile-level error, BEGIN TRY --- END TRY is not able to cover it, what's worse, since we are in function, EXEC(#string),sp_executesql, SELECT * FROM OPENQUERY('...'), sp_testlinkedserver none of them works. the worst, I cannot afford to take risk of changing it into an SP (the grammar SELECT dbo.ttest1() is penetrated everywhere in the project).
Are there any good solutions?
I have a table where data does not initially exist until an action is taken that stores all settings made by client in one-go. To illustrate this simply, a button click that stores all column values off a (HTML) table into a database table (let's call this dbo.Settings).
So instead of inserting into this dbo.Settings all the default values prior to user making any changes to their individual settings (ever), I kind of created the pseudo data for them that will be returned whenever requested, kind of like SELECT-ing the default values:
SELECT
CanView = ISNULL(CanView, 1),
CanRead = ISNULL(CanRead, 1),
CanWrite = ISNULL(CanWrite, 0)
FROM
dbo.Settings AS s
WHERE
UserId = #id
Rather than doing:
IF NOT EXISTS(SELECT * FROM dbo.Settings WHERE UserId = #id)
BEGIN
INSERT INTO dbo.Settings (UserId, CanView, CanRead, CanWrite)
VALUES (#id, 1, 1, 0)
END
The problem with this is whenever I need to add a new setting column in the future, I now have to note one more procedure to modify/add the default value for this column as well -- which I don't like. Using TRIGGER would be an option but I wonder what the best practice in managing data like this would be. Or would you do something like this:
CREATE PROC Settings_CreateOrModify
#userId INT,
#canView BIT = NULL,
#canRead BIT = NULL,
#canWrite BIT = NULL
AS
BEGIN
IF EXISTS(SELECT * FROM dbo.Settings WHERE UserId = #userId) BEGIN
UPDATE s
SET
CanView = #canView,
CanRead = #canRead,
CanWrite = #canWrite
FROM
dbo.Settings AS s
WHERE
s.UserId = #userId AND
(#canView IS NULL OR #canView <> s.CanView) AND
(#canRead IS NULL OR #canRead <> s.CanRead) AND
(#canWrite IS NULL OR #canWrite <> s.CanWrite)
END
ELSE BEGIN
INSERT INTO
dbo.Settings(UserId, CanView, CanRead, CanWrite)
SELECT
#userId, #canView, #canRead, #canWrite
END
END
How would you handle data structure like this? Any recommendation or correction would be greatly appreciated. Thanks in advance!
Your SP is a good way to go, and doing it like this is commonly called an "UPSERT".
It also looks to me as if the block:
(#canView IS NULL OR #canView <> s.CanView) AND
(#canRead IS NULL OR #canRead <> s.CanRead) AND
(#canWrite IS NULL OR #canWrite <> s.CanWrite)
is problematic since it causes the UPDATE to run only if ALL parameters changed their value. I don't think that's what you wanted to say. Just SET the three values regardless of what's already there.
You still end up with three places to change when you add a new setting: The Table, the Upsert and the Defaults.
One very different approach is this:
Apply the defaults to the columns in the table definition.
Whenever you need the values for a new user, do: INSERT INTO dbo.Settings(UserId) The defaults will fill the rest of the columns.
Now you can retrieve the values for ALL users (new or not) in the same way from the table.
Since you already inserted the user in step 2, you know the userid is there already and you can always save the changes via a simple update.
This eliminates the SP and the need of providing the defaults in one extra place.
I m trying to write if statement to give error message if user try to add existing ID number.When i try to enter existing id i get error .untill here it s ok but when i type another id no and fill the fields(name,adress etc) it doesnt go to database.
METHOD add_employee.
DATA: IT_EMP TYPE TABLE OF ZEMPLOYEE_20.
DATA:WA_EMP TYPE ZEMPLOYEE_20.
Data: l_count type i value '2'.
SELECT * FROM ZEMPLOYEE_20 INTO TABLE IT_EMP.
LOOP AT IT_EMP INTO WA_EMP.
IF wa_emp-EMPLOYEE_ID eq pa_id.
l_count = l_count * '0'.
else.
l_count = l_count * '1'.
endif.
endloop.
If l_count eq '2'.
WA_EMP-EMPLOYEE_ID = C_ID.
WA_EMP-EMPLOYEE_NAME = C_NAME.
WA_EMP-EMPLOYEE_ADDRESS = C_ADD.
WA_EMP-EMPLOYEE_SALARY = C_SAL.
WA_EMP-EMPLOYEE_TYPE = C_TYPE.
APPEND wa_emp TO it_emp.
INSERT ZEMPLOYEE_20 FROM TABLE it_emp.
CALL FUNCTION 'POPUP_TO_DISPLAY_TEXT'
EXPORTING
TITEL = 'INFO'
TEXTLINE1 = 'Record Added Successfully.'.
elseif l_count eq '0'.
CALL FUNCTION 'POPUP_TO_DISPLAY_TEXT'
EXPORTING
TITEL = 'INFO'
TEXTLINE1 = 'Selected ID already in database.Please type another ID no.'.
ENDIF.
ENDMETHOD.
I'm not sure I'm getting your explanation. Why are you trying to re-insert all the existing entries back into the table? You're just trying to insert C_ID etc if it doesn't exist yet? Why do you need all the existing entries for that?
If so, throw out that select and the loop completely, you don't need it. You have a few options...
Just read the table with your single entry
SELECT SINGLE * FROM ztable INTO wa WITH KEY ID = C_ID etc.
IF SY-SUBRC = 0.
"this entry exists. popup!
ENDIF.
Use a modify statement
This will overwrite duplicate entries with new data (so non key fields may change this way), it wont fail. No need for a popup.
MODIFY ztable FROM wa.
Catch the SQL exceptions instead of making it dump
If the update fails because of an exception, you can always catch it and deal with exceptional situations.
TRY .
INSERT ztable FROM wa.
CATCH sapsql_array_insert_duprec.
"do your popup, the update failed because of duplicate records
ENDTRY.
I think there's a bug when appending in internal table 'IT_EMP' and inserting in 'ZEMPLOYEE_20' table.
Suppose you append the first time and then you insert. But when you append the second time you will have 2 records in 'IT_EMP' that are going to be inserted in 'ZEMPLOYEE_20'. That is because you don't refresh or clear the internal table and there you will have a runtime error.
According to SAP documentation on 'Inserting Lines into Tables ':
Inserting Several Lines
To insert several lines into a database table, use the following:
INSERT FROM TABLE [ACCEPTING DUPLICATE KEYS] . This
writes all lines of the internal table to the database table in
one single operation. The same rules apply to the line type of
as to the work area described above. If the system is able to
insert all of the lines from the internal table, SY-SUBRC is set to 0.
If one or more lines cannot be inserted because the database already
contains a line with the same primary key, a runtime error occurs.
Maybe the right direction here is trying to insert the work area directly but before you must check if record already exists using the primary key.
Check the SAP documentation on this issue clicking the link before.
On the other hand, once l_count is zero because of l_count = l_count * '0'. that value will never change to any other number making that you won't append or insert again.
why are you retrieving all entries from zemployee_20 ?
You can directly check wether the 'id' exists already or not by using select single. If exists, then show message, if not, add.
It is recommended to retrieve only one field when its needed and not the entire table with asterisc *
SELECT single employee_id FROM ZEMPLOYEE_20 where employee_id = p_id INTO v_id. ( or field in structure )
if sy-subrc = 0. "exists
"show message
else. "not existing id
"populate structure and then add record to Z table
endif.
Furthermore, l_count is not only unnecessary but also bad implemented.
You can directly use the insert query,if the sy-subrc is unsuccessful raise the error message.
WA_EMP-EMPLOYEE_ID = C_ID.
WA_EMP-EMPLOYEE_NAME = C_NAME.
WA_EMP-EMPLOYEE_ADDRESS = C_ADD.
WA_EMP-EMPLOYEE_SALARY = C_SAL.
WA_EMP-EMPLOYEE_TYPE = C_TYPE.
INSERT ZEMPLOYEE_20 FROM WA_EMP.
If sy-subrc <> 0.
Raise the Exception.
Endif.
Hi I am using postgresql 8.1.22, I am trying to setup postgresql auditing using the following function.
CREATE OR REPLACE FUNCTION audit.if_modified_func() RETURNS TRIGGER AS $body$
DECLARE
v_old_data TEXT;
v_new_data TEXT;
BEGIN
/* If this actually for real auditing (where you need to log EVERY action),
then you would need to use something like dblink or plperl that could log outside the transaction,
regardless of whether the transaction committed or rolled back.
*/
/* This dance with casting the NEW and OLD values to a ROW is not necessary in pg 9.0+ */
IF (TG_OP = 'UPDATE') THEN
v_old_data := ROW(OLD.*);
v_new_data := ROW(NEW.*);
INSERT INTO audit.logged_actions (schema_name,table_name,user_name,action,original_data,new_data,query)
VALUES (TG_TABLE_SCHEMA::TEXT,TG_TABLE_NAME::TEXT,session_user::TEXT,substring(TG_OP,1,1),v_old_data,v_new_data, current_query());
RETURN NEW;
ELSIF (TG_OP = 'DELETE') THEN
v_old_data := ROW(OLD.*);
INSERT INTO audit.logged_actions (schema_name,table_name,user_name,action,original_data,query)
VALUES (TG_TABLE_SCHEMA::TEXT,TG_TABLE_NAME::TEXT,session_user::TEXT,substring(TG_OP,1,1),v_old_data, current_query());
RETURN OLD;
ELSIF (TG_OP = 'INSERT') THEN
v_new_data := ROW(NEW.*);
INSERT INTO audit.logged_actions (schema_name,table_name,user_name,action,new_data,query)
VALUES (TG_TABLE_SCHEMA::TEXT,TG_TABLE_NAME::TEXT,session_user::TEXT,substring(TG_OP,1,1),v_new_data, current_query());
RETURN NEW;
ELSE
RAISE WARNING '[AUDIT.IF_MODIFIED_FUNC] - Other action occurred: %, at %',TG_OP,now();
RETURN NULL;
END IF;
EXCEPTION
WHEN data_exception THEN
RAISE WARNING '[AUDIT.IF_MODIFIED_FUNC] - UDF ERROR [DATA EXCEPTION] - SQLSTATE: %, SQLERRM: %',SQLSTATE,SQLERRM;
RETURN NULL;
WHEN unique_violation THEN
RAISE WARNING '[AUDIT.IF_MODIFIED_FUNC] - UDF ERROR [UNIQUE] - SQLSTATE: %, SQLERRM: %',SQLSTATE,SQLERRM;
RETURN NULL;
WHEN OTHERS THEN
RAISE WARNING '[AUDIT.IF_MODIFIED_FUNC] - UDF ERROR [OTHER] - SQLSTATE: %, SQLERRM: %',SQLSTATE,SQLERRM;
RETURN NULL;
END;
$body$
LANGUAGE plpgsql
SECURITY DEFINER
But if you observe in the above function current_query() is not coming with the mentioned language plpgsql. It throws some error. When I googled I found that in order to use current_query() function PL/CTL language must be installed. I tried to install as mentioned below. It throws an error. So kindly help me how to install PL/CTL language into my database so that current_query() function should work
-bash-3.2$ createlang -d dbname pltcl
createlang: language installation failed: ERROR: could not access file "$libdir/pltcl": No such file or directory
Okay as you suggested I created that current_query() function,but this time I got some thing like this , What i did is ,
CREATE TABLE phonebook(phone VARCHAR(32), firstname VARCHAR(32), lastname VARCHAR(32), address VARCHAR(64));
CREATE TRIGGER phonebook_auditt AFTER INSERT OR UPDATE OR DELETE ON phonebook
FOR EACH ROW EXECUTE PROCEDURE audit.if_modified_func();
INSERT INTO phonebook(phone, firstname, lastname, address) VALUES('9966888200', 'John', 'Doe', 'North America');
for testing the function i created a table named phonebook and created a trigger so that the function mentioned above audit.if_modified_func() will be executed after any insert or update or delete.the row is getting inserted but I am getting a error reg the audit.if_modified_func() function .the error is as follows
WARNING: [AUDIT.IF_MODIFIED_FUNC] - UDF ERROR [OTHER] - SQLSTATE: 42703, SQLERRM: column "*" not found in data type phonebook
Query returned successfully: 1 rows affected, 10 ms execution time.
Kindly tell me what can i do to get rid of the above error.
Not sure where you found the information about current_query and pltcl. These are unrelated. The reason why you can't find pltcl is simply because you're using too old PostgreSQL. current_query() has been added to Pg in version 8.4.
Is there any particular reason why you're using such old version? It is no longer supported, and it lacks almost 8 years of added features!
If you have to use 8.1, you might want to define:
create function current_query() returns text as '
select current_query from pg_stat_activity where procpid = pg_backend_pid();
' language sql;
But it is much better idea just to upgrade.
As for edited and added second question - it's very likely that Pg 8.1 cannot use "row.*" construct. Find who wrote the original code with the "dance comments", and ask about it. Perhaps it was meant to work in newer Pgs.