I have two tables with fields as shown below :-
tbl_emp --> id(auto generate, auto increment, primary key),name, dob
tbl_login --> id(refers to id in tbl_emp, primary key), password
I have a web form which reads the name, password and date of birth(dob), and a submit button. On pressing the submit button, the data is inserted into the first table, and also to the second table. It would be easy to insert data to the second column if I had a way to access the "id" field from the first table.
The query I have is :-
insert into tbl_emp (name,dob) values(#name, #dob);
insert into tbl_login (id,password) values((select id from tbl_emp where id=(select id from tbl_emp where id=id)), #password)
The problem that I encounter with the above coeds is :
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
The statement has been terminated.
You could use the SCOPE_IDENTIY function:
insert into tbl_emp (name,dob) values(#name, #dob);
insert into tbl_login (id,password)
select id, #password
from tbl_emp
where id = SCOPE_IDENTITY();
Related
I have create a table person(id, name ,samenamecount).The samenamecount attribute can be null but for each row can store the row count for same names.I am achieving this by calling a stored procedure inside a after insert trigger.Below is my code.
create or replace procedure automatic(s in person.name%type)
AS
BEGIN
update person set samenamecount=(select count(*) from person where name=s) where name=s;
END;
create or replace trigger inserttrigger
after insert
on person
for each row
declare
begin
automatic(:new.name);
end;
On inserting a row it is giving error like
table ABCD.PERSON is mutating, trigger/function may not see it.
Can somebody help me to figure out this?
If you have the table:
CREATE TABLE person (
id NUMBER
GENERATED ALWAYS AS IDENTITY
CONSTRAINT person__id__pk PRIMARY KEY,
name VARCHAR2(20)
NOT NULL
);
Then rather than creating a trigger, instead, you could use a view:
CREATE VIEW person_view (
id,
name,
samenamecount
) AS
SELECT id,
name,
COUNT(*) OVER (PARTITION BY name)
FROM person;
You can use the trigger:
CREATE TRIGGER inserttrigger
AFTER INSERT ON person
BEGIN
MERGE INTO person dst
USING (
SELECT ROWID AS rid,
COUNT(*) OVER (PARTITION BY name) AS cnt
FROM person
) src
ON (src.rid = dst.ROWID)
WHEN MATCHED THEN
UPDATE SET samenamecount = src.cnt;
END;
/
fiddle
If you want to make it more efficient then you could use a compound trigger and collate the names that are being inserted and only update the matching rows.
In a sqlite3 database I would like to create a trigger on a view so that I can insert data over the view. Inside the trigger I would like to insert something in the tblmedia table. The id of the inserted row should be now also inserted into the tblbook as id.
In sqlite there are no variables. Otherwise I would store the returning value in the variable and would use it in the second query.
Can this even be achieved in sqlite?
Following my sql schema:
CREATE TABLE tblmedia(
id INTEGER PRIMARY KEY NOT NULL,
title VARCHAR NOT NULL,
raiting INTEGER,
file_name VARCHAR NOT NULL,
media_type TEXT NOT NULL
);
CREATE TABLE tblbook(
id INTEGER PRIMARY KEY NOT NULL,
author VARCHAR,
FOREIGN KEY (id) REFERENCES tblmedia(id) ON DELETE CASCADE
);
CREATE VIEW book AS
SELECT
m.id as id,
m.title as title,
b.author as author,
m.raiting as raiting,
m.file_name as file_name
FROM tblbook b
LEFT JOIN tblmedia m ON m.id = b.id;
CREATE TRIGGER insert_book
INSTEAD OF INSERT ON book
BEGIN
INSERT INTO tblmedia(title, raiting, file_name)
VALUES(new.title, new.raiting, new.file_name);
INSERT INTO tblbook(id, author)
VALUES (xx, new.author); -- xx should be the id from the previous insert
END
I have below two tables. I wrote after insert trigger on employees table. If i insert the record in employees table it will insert the record in employee_audits table.
Both table have primary key column (id). suppose if you try to insert record ID value which does not exists in employees table and exists in employee_audits table, it shows the
error duplicate key value violates unique constraint "employee_audits_pkey" and also it is not inserting record in employees table. Both transaction failed.
But i want to insert the record in employees table.
CREATE TABLE employees(
id SERIAL PRIMARY KEY,
first_name VARCHAR(40) NOT NULL,
last_name VARCHAR(40) NOT NULL
);
CREATE TABLE employee_audits (
id SERIAL PRIMARY KEY,
last_name VARCHAR(40) NOT NULL,
changed_on TIMESTAMP(6) NOT NULL
)
The trigger function:
CREATE OR REPLACE FUNCTION log_last_name_changes()
RETURNS trigger AS
$BODY$
BEGIN
INSERT INTO employee_audits(last_name,changed_on)
VALUES(NEW.last_name,now());
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
The trigger definition:
CREATE TRIGGER last_name_changes
AFTER INSERT
ON employees
FOR EACH ROW
EXECUTE PROCEDURE log_last_name_changes();
INSERT INTO employees (first_name, last_name)
VALUES ('John', 'Doe');
SELECT * FROM EMPLOYEES
id first_name last_name
1 "John" "Doe"
SELECT * FROM EMPLOYEE_AUDITS
ID last_name CHANGED_ON
1 "Doe" "2019-12-27 17:21:13.934"
Manual insert on second table
insert into employee_audits values(2,'banu','2019-12-27 17:21:13.934')
Manual insert on first table
INSERT INTO employees (first_name, last_name)
VALUES ('David', 'Raj');
Error duplicate key value violates unique constraint "employee_audits_pkey"
is it possible to insert record in employees table?
If you have a serial column you should never provide the value for it manually. Manually providing a value for a serial will not advance the sequence behind that column, so the next time you insert without specifying the id column, the next sequence value will be taken which is 2 as the sequence was only advanced once.
So instead of:
insert into employee_audits values(2,'banu','2019-12-27 17:21:13.934')
Just use:
insert into employee_audits (last_name, changed_at)
values ('banu','2019-12-27 17:21:13.934');
This behaviour of the serial columns is one of the reasons why it's highly recommended to use identity columns with modern Postgres versions.
I have an SQLite database. I am trying to insert values (users_id, lessoninfo_id) in table bookmarks, only if both do not exist before in a row.
INSERT INTO bookmarks(users_id,lessoninfo_id)
VALUES(
(SELECT _id FROM Users WHERE User='"+$('#user_lesson').html()+"'),
(SELECT _id FROM lessoninfo
WHERE Lesson="+lesson_no+" AND cast(starttime AS int)="+Math.floor(result_set.rows.item(markerCount-1).starttime)+")
WHERE NOT EXISTS (
SELECT users_id,lessoninfo_id from bookmarks
WHERE users_id=(SELECT _id FROM Users
WHERE User='"+$('#user_lesson').html()+"') AND lessoninfo_id=(
SELECT _id FROM lessoninfo
WHERE Lesson="+lesson_no+")))
This gives an error saying:
db error near where syntax.
If you never want to have duplicates, you should declare this as a table constraint:
CREATE TABLE bookmarks(
users_id INTEGER,
lessoninfo_id INTEGER,
UNIQUE(users_id, lessoninfo_id)
);
(A primary key over both columns would have the same effect.)
It is then possible to tell the database that you want to silently ignore records that would violate such a constraint:
INSERT OR IGNORE INTO bookmarks(users_id, lessoninfo_id) VALUES(123, 456)
If you have a table called memos that has two columns id and text you should be able to do like this:
INSERT INTO memos(id,text)
SELECT 5, 'text to insert'
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 AND text = 'text to insert');
If a record already contains a row where text is equal to 'text to insert' and id is equal to 5, then the insert operation will be ignored.
I don't know if this will work for your particular query, but perhaps it give you a hint on how to proceed.
I would advice that you instead design your table so that no duplicates are allowed as explained in #CLs answer below.
For a unique column, use this:
INSERT OR REPLACE INTO tableName (...) values(...);
For more information, see: sqlite.org/lang_insert
insert into bookmarks (users_id, lessoninfo_id)
select 1, 167
EXCEPT
select user_id, lessoninfo_id
from bookmarks
where user_id=1
and lessoninfo_id=167;
This is the fastest way.
For some other SQL engines, you can use a Dummy table containing 1 record.
e.g:
select 1, 167 from ONE_RECORD_DUMMY_TABLE
I have a list of users who should receive the message. They are in the table subscribe. Now I'd like to insert a message for every one of these users. My query is
insert into message(user, type, theId)
select (select user from subscribe_message), #type, #id
At the moment it is empty. I get the error message.user may not be NULL. Shouldn't it not insert any rows? When I have more than one row it inserts the first row only. How do I write this so it will insert 0 to many rows?
Try this
INSERT INTO message ( user, type, theId )
SELECT subscribe_message.user, #type, #id
FROM subscribe_message