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.
I want to update OrigOrderNbr and OrigOrderType (QT type) because when I create first both of column are Null value. But after S2 was created (QT converted to S2) the OrigOrderType and OrigOrderNbr (S2) take from QT reference. Instead of that, I want to update it to QT also.
http://i.stack.imgur.com/6ipFa.png
http://i.stack.imgur.com/E6qzT.png
CREATE TRIGGER tgg_SOOrder
ON dbo.SOOrder
FOR INSERT
AS
DECLARE #tOrigOrderType char(2),
#tOrigOrderNbr nvarchar(15)
SELECT #tOrigOrderType = i.OrderType,
#tOrigOrderNbr = i.OrderNbr
FROM inserted i
UPDATE dbo.SOOrder
SET OrigOrderType = #tOrigOrderType,
OrigOrderNbr = #tOrigOrderNbr
FROM inserted i
WHERE dbo.SOOrder.CompanyID='2'
and dbo.SOOrder.OrderType=i.OrigOrderType
and dbo.SOOrder.OrderNbr=i.OrigOrderNbr
GO
After I run that trigger, it showed the message 'Error #91: Another process has updated 'SOOrder' record. Your changes will be lost.'.
Per long string of comments, including some excellent suggestions in regards to proper trigger writing techniques by #marc_s and #Damien_The_Unbeliever, as well as my better understanding of your issue at this point, here's the re-worked trigger:
CREATE TRIGGER tgg_SOOrder
ON dbo.SOOrder
FOR INSERT
AS
--Update QT record with S2 record's order info
UPDATE SOOrder
SET OrigOrderType = 'S2'
, OrigOrderNbr = i.OrderNbr
FROM SOOrder dest
JOIN inserted i
ON dest.OrderNbr = i.OrigOrderNbr
WHERE dest.OrderType = 'QT'
AND i.OrderType = 'S2'
AND dest.CompanyID = 2 --Business logic constraint
AND dest.OrigOrderNbr IS NULL
AND dest.OrigOrderType IS NULL
Basically, the idea is to update any record of type "QT" once a matching record of type "S2" is created. Matching here means that OrigOrderNbr of S2 record is the same as OrderNbr of QT record. I kept your business logic constraint in regards to CompanyID being set to 2. Additionally, we only care to modify QT records that have OrigOrderNbr and OrigOrderType set to NULL.
This trigger does not rely on a single-row insert; it will work regardless of the number of rows inserted - which is far less likely to break down the line.
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.
I have a table column that uses an enum type. I wish to update that enum type to have an additional possible value. I don't want to delete any existing values, just add the new value. What is the simplest way to do this?
PostgreSQL 9.1 introduces ability to ALTER Enum types:
ALTER TYPE enum_type ADD VALUE 'new_value'; -- appends to list
ALTER TYPE enum_type ADD VALUE 'new_value' BEFORE 'old_value';
ALTER TYPE enum_type ADD VALUE 'new_value' AFTER 'old_value';
NOTE if you're using PostgreSQL 9.1 or later, and you are ok with making changes outside of a transaction, see this answer for a simpler approach.
I had the same problem few days ago and found this post. So my answer can be helpful for someone who is looking for solution :)
If you have only one or two columns which use the enum type you want to change, you can try this. Also you can change the order of values in the new type.
-- 1. rename the enum type you want to change
alter type some_enum_type rename to _some_enum_type;
-- 2. create new type
create type some_enum_type as enum ('old', 'values', 'and', 'new', 'ones');
-- 3. rename column(s) which uses our enum type
alter table some_table rename column some_column to _some_column;
-- 4. add new column of new type
alter table some_table add some_column some_enum_type not null default 'new';
-- 5. copy values to the new column
update some_table set some_column = _some_column::text::some_enum_type;
-- 6. remove old column and type
alter table some_table drop column _some_column;
drop type _some_enum_type;
3-6 should be repeated if there is more than 1 column.
A possible solution is the following; precondition is, that there are not conflicts in the used enum values. (e.g. when removing an enum value, be sure that this value is not used anymore.)
-- rename the old enum
alter type my_enum rename to my_enum__;
-- create the new enum
create type my_enum as enum ('value1', 'value2', 'value3');
-- alter all you enum columns
alter table my_table
alter column my_column type my_enum using my_column::text::my_enum;
-- drop the old enum
drop type my_enum__;
Also in this way the column order will not be changed.
If you are using Postgres 12 (or later) you can just run ALTER TYPE ... ADD VALUE inside of transaction (documentation).
If ALTER TYPE ... ADD VALUE (the form that adds a new value to an enum
type) is executed inside a transaction block, the new value cannot be
used until after the transaction has been committed.
So no hacks needed in migrations.
UPD: here is an example (thanks to Nick for it)
ALTER TYPE enum_type ADD VALUE 'new_value';
If you fall into situation when you should add enum values in transaction, f.e. execute it in flyway migration on ALTER TYPE statement you will be get error ERROR: ALTER TYPE ... ADD cannot run inside a transaction block (see flyway issue #350) you could add such values into pg_enum directly as workaround (type_egais_units is name of target enum):
INSERT INTO pg_enum (enumtypid, enumlabel, enumsortorder)
SELECT 'type_egais_units'::regtype::oid, 'NEW_ENUM_VALUE', ( SELECT MAX(enumsortorder) + 1 FROM pg_enum WHERE enumtypid = 'type_egais_units'::regtype )
Complementing #Dariusz 1
For Rails 4.2.1, there's this doc section:
== Transactional Migrations
If the database adapter supports DDL transactions, all migrations will
automatically be wrapped in a transaction. There are queries that you
can't execute inside a transaction though, and for these situations
you can turn the automatic transactions off.
class ChangeEnum < ActiveRecord::Migration
disable_ddl_transaction!
def up
execute "ALTER TYPE model_size ADD VALUE 'new_value'"
end
end
just in case, if you are using Rails and you have several statements you will need to execute one by one, like:
execute "ALTER TYPE XXX ADD VALUE IF NOT EXISTS 'YYY';"
execute "ALTER TYPE XXX ADD VALUE IF NOT EXISTS 'ZZZ';"
From Postgres 9.1 Documentation:
ALTER TYPE name ADD VALUE new_enum_value [ { BEFORE | AFTER } existing_enum_value ]
Example:
ALTER TYPE user_status ADD VALUE 'PROVISIONAL' AFTER 'NORMAL'
Disclaimer: I haven't tried this solution, so it might not work ;-)
You should be looking at pg_enum. If you only want to change the label of an existing ENUM, a simple UPDATE will do it.
To add a new ENUM values:
First insert the new value into pg_enum. If the new value has to be the last, you're done.
If not (you need to a new ENUM value in between existing ones), you'll have to update each distinct value in your table, going from the uppermost to the lowest...
Then you'll just have to rename them in pg_enum in the opposite order.
Illustration
You have the following set of labels:
ENUM ('enum1', 'enum2', 'enum3')
and you want to obtain:
ENUM ('enum1', 'enum1b', 'enum2', 'enum3')
then:
INSERT INTO pg_enum (OID, 'newenum3');
UPDATE TABLE SET enumvalue TO 'newenum3' WHERE enumvalue='enum3';
UPDATE TABLE SET enumvalue TO 'enum3' WHERE enumvalue='enum2';
then:
UPDATE TABLE pg_enum SET name='enum1b' WHERE name='enum2' AND enumtypid=OID;
And so on...
I can't seem to post a comment, so I'll just say that updating pg_enum works in Postgres 8.4 . For the way our enums are set up, I've added new values to existing enum types via:
INSERT INTO pg_enum (enumtypid, enumlabel)
SELECT typelem, 'NEWENUM' FROM pg_type WHERE
typname = '_ENUMNAME_WITH_LEADING_UNDERSCORE';
It's a little scary, but it makes sense given the way Postgres actually stores its data.
Updating pg_enum works, as does the intermediary column trick highlighted above. One can also use USING magic to change the column's type directly:
CREATE TYPE test AS enum('a', 'b');
CREATE TABLE foo (bar test);
INSERT INTO foo VALUES ('a'), ('b');
ALTER TABLE foo ALTER COLUMN bar TYPE varchar;
DROP TYPE test;
CREATE TYPE test as enum('a', 'b', 'c');
ALTER TABLE foo ALTER COLUMN bar TYPE test
USING CASE
WHEN bar = ANY (enum_range(null::test)::varchar[])
THEN bar::test
WHEN bar = ANY ('{convert, these, values}'::varchar[])
THEN 'c'::test
ELSE NULL
END;
As long as you've no functions that explicitly require or return that enum, you're good. (pgsql will complain when you drop the type if there are.)
Also, note that PG9.1 is introducing an ALTER TYPE statement, which will work on enums:
http://developer.postgresql.org/pgdocs/postgres/release-9-1-alpha.html
Can't add a comment to the appropriate place, but ALTER TABLE foo ALTER COLUMN bar TYPE new_enum_type USING bar::text::new_enum_type with a default on the column failed. I had to:
ALTER table ALTER COLUMN bar DROP DEFAULT;
and then it worked.
Here is a more general but a rather fast-working solution, which apart from changing the type itself updates all columns in the database using it. The method can be applied even if a new version of ENUM is different by more than one label or misses some of the original ones. The code below replaces my_schema.my_type AS ENUM ('a', 'b', 'c') with ENUM ('a', 'b', 'd', 'e'):
CREATE OR REPLACE FUNCTION tmp() RETURNS BOOLEAN AS
$BODY$
DECLARE
item RECORD;
BEGIN
-- 1. create new type in replacement to my_type
CREATE TYPE my_schema.my_type_NEW
AS ENUM ('a', 'b', 'd', 'e');
-- 2. select all columns in the db that have type my_type
FOR item IN
SELECT table_schema, table_name, column_name, udt_schema, udt_name
FROM information_schema.columns
WHERE
udt_schema = 'my_schema'
AND udt_name = 'my_type'
LOOP
-- 3. Change the type of every column using my_type to my_type_NEW
EXECUTE
' ALTER TABLE ' || item.table_schema || '.' || item.table_name
|| ' ALTER COLUMN ' || item.column_name
|| ' TYPE my_schema.my_type_NEW'
|| ' USING ' || item.column_name || '::text::my_schema.my_type_NEW;';
END LOOP;
-- 4. Delete an old version of the type
DROP TYPE my_schema.my_type;
-- 5. Remove _NEW suffix from the new type
ALTER TYPE my_schema.my_type_NEW
RENAME TO my_type;
RETURN true;
END
$BODY$
LANGUAGE 'plpgsql';
SELECT * FROM tmp();
DROP FUNCTION tmp();
The whole process will run fairly quickly, because if the order of labels persists, no actual change of data will happen. I applied the method on 5 tables using my_type and having 50,000−70,000 rows in each, and the whole process took just 10 seconds.
Of course, the function will return an exception in case if labels that are missing in the new version of the ENUM are used somewhere in the data, but in such situation something should be done beforehand anyway.
For those looking for an in-transaction solution, the following seems to work.
Instead of an ENUM, a DOMAIN shall be used on type TEXT with a constraint checking that the value is within the specified list of allowed values (as suggested by some comments). The only problem is that no constraint can be added (and thus neither modified) to a domain if it is used by any composite type (the docs merely says this "should eventually be improved"). Such a restriction may be worked around, however, using a constraint calling a function, as follows.
START TRANSACTION;
CREATE FUNCTION test_is_allowed_label(lbl TEXT) RETURNS BOOL AS $function$
SELECT lbl IN ('one', 'two', 'three');
$function$ LANGUAGE SQL IMMUTABLE;
CREATE DOMAIN test_domain AS TEXT CONSTRAINT val_check CHECK (test_is_allowed_label(value));
CREATE TYPE test_composite AS (num INT, word test_domain);
CREATE TABLE test_table (val test_composite);
INSERT INTO test_table (val) VALUES ((1, 'one')::test_composite), ((3, 'three')::test_composite);
-- INSERT INTO test_table (val) VALUES ((4, 'four')::test_composite); -- restricted by the CHECK constraint
CREATE VIEW test_view AS SELECT * FROM test_table; -- just to show that the views using the type work as expected
CREATE OR REPLACE FUNCTION test_is_allowed_label(lbl TEXT) RETURNS BOOL AS $function$
SELECT lbl IN ('one', 'two', 'three', 'four');
$function$ LANGUAGE SQL IMMUTABLE;
INSERT INTO test_table (val) VALUES ((4, 'four')::test_composite); -- allowed by the new effective definition of the constraint
SELECT * FROM test_view;
CREATE OR REPLACE FUNCTION test_is_allowed_label(lbl TEXT) RETURNS BOOL AS $function$
SELECT lbl IN ('one', 'two', 'three');
$function$ LANGUAGE SQL IMMUTABLE;
-- INSERT INTO test_table (val) VALUES ((4, 'four')::test_composite); -- restricted by the CHECK constraint, again
SELECT * FROM test_view; -- note the view lists the restricted value 'four' as no checks are made on existing data
DROP VIEW test_view;
DROP TABLE test_table;
DROP TYPE test_composite;
DROP DOMAIN test_domain;
DROP FUNCTION test_is_allowed_label(TEXT);
COMMIT;
Previously, I used a solution similar to the accepted answer, but it is far from being good once views or functions or composite types (and especially views using other views using the modified ENUMs...) are considered. The solution proposed in this answer seems to work under any conditions.
The only disadvantage is that no checks are performed on existing data when some allowed values are removed (which might be acceptable, especially for this question). (A call to ALTER DOMAIN test_domain VALIDATE CONSTRAINT val_check ends up with the same error as adding a new constraint to the domain used by a composite type, unfortunately.)
Note that a slight modification such as CHECK (value = ANY(get_allowed_values())), where get_allowed_values() function returned the list of allowed values, would not work - which is quite strange, so I hope the solution proposed above works reliably (it does for me, so far...). (it works, actually - it was my error)
As discussed above, ALTER command cannot be written inside a transaction. The suggested way is to insert into the pg_enum table directly, by retrieving the typelem from pg_type table and calculating the next enumsortorder number;
Following is the code that I use. (Checks if duplicate value exists before inserting (constraint between enumtypid and enumlabel name)
INSERT INTO pg_enum (enumtypid, enumlabel, enumsortorder)
SELECT typelem,
'NEW_ENUM_VALUE',
(SELECT MAX(enumsortorder) + 1
FROM pg_enum e
JOIN pg_type p
ON p.typelem = e.enumtypid
WHERE p.typname = '_mytypename'
)
FROM pg_type p
WHERE p.typname = '_mytypename'
AND NOT EXISTS (
SELECT * FROM
pg_enum e
JOIN pg_type p
ON p.typelem = e.enumtypid
WHERE e.enumlabel = 'NEW_ENUM_VALUE'
AND p.typname = '_mytypename'
)
Note that your type name is prepended with an underscore in the pg_type table. Also, the typname needs to be all lowercase in the where clause.
Now this can be written safely into your db migrate script.
DB::statement("ALTER TABLE users DROP CONSTRAINT users_user_type_check");
$types = ['old_type1', 'old_type1', 'new_type3'];
$result = join( ', ', array_map(function ($value){
return sprintf("'%s'::character varying", $value);
}, $types));
DB::statement("ALTER TABLE users ADD CONSTRAINT users_user_type_check CHECK (user_type::text = ANY (ARRAY[$result]::text[]))");
When using Navicat you can go to types (under view -> others -> types) - get the design view of the type - and click the "add label" button.
I don't know if have other option but we can drop the value using:
select oid from pg_type where typname = 'fase';'
select * from pg_enum where enumtypid = 24773;'
select * from pg_enum where enumtypid = 24773 and enumsortorder = 6;
delete from pg_enum where enumtypid = 24773 and enumsortorder = 6;
Simplest: get rid of enums. They are not easily modifiable, and thus should very rarely be used.