Is it possible to insert duplicate values into a database row only if a different column in the same table is unique? Thanks for your help.
database table setup:
login_time int(15) [unique key] | user_id int(15) | time_worked varchar(64)
This is my insert statment.
What i need is to only insert if user_id or login_time is unique.
And to not insert if both user_id and login_time match another row in the database.
INSERT INTO `ucm_user_timelog` VALUES (' . intval($user_id) .
', ' . $timeWorked . ', ' . $logInTime . ')
Related
I have trouble, I have table named my_table)
id name
1 A
2 B
3 C
and I want to insert top 2 so, values have autoincrement automaticaly like this
insert into my_table (name) values (A), (B);
Is this possible in postgressql?
May be I should have count() + 1, then count() + 2 here
insert into my_table (id, name) values (count(*) + 1, A), (count(*) + 2, B);
or something like this
because my id has constraint
BIGSEREIAL PRIMARY KEY NOT NULL
And I cant add values without getting the last id in table.
You can do:
create table my_table (
id int not null generated always as identity,
name varchar(10) not null
);
insert into my_table (name) values ('A'), ('B');
Then:
select * from my_table;
Result:
id name
-- ----
1 A
2 B
See running example at db<>fiddle.
I want to update status to inactive ( Status=’I’) for all duplicate record except one in sql, default status is active (Status=’A’ ) for all records in table. It should be done without using any inbuilt sql function ex: row_num(), rank(), set rowcount etc.
CREATE TABLE dup_test
(
Emp_ID INT,
Mgr_ID INT,
Status Varchar(5)
)
INSERT INTO dup_test VALUES (1,1,'A');
INSERT INTO dup_test VALUES (1,1,'A');
INSERT INTO dup_test VALUES (1,1,'A');
INSERT INTO dup_test VALUES (2,2,'A');
INSERT INTO dup_test VALUES (2,2,'A');
INSERT INTO dup_test VALUES (3,3,'A');
Expected Result:
Emp_ID, Mgr_ID, Status
1 1 A
1 1 I
1 1 I
2 2 A
2 2 I
3 3 A
Thanks in advance.
Alter the table and add an identity column (ID):
ALTER TABLE dup_test
ADD id INT NOT NULL IDENTITY (1, 1)
Then something like the following will work:
UPDATE dup_test SET
Status='I'
FROM dup_test dt LEFT OUTER JOIN
(SELECT Emp_ID, MAX(ID) AS maxid
FROM dup_test
GROUP BY Emp_ID) AS dt2 ON dt.Emp_ID=dt2.Emp_ID AND dt.ID=dt2.maxid
WHERE dt2.maxID IS NULL
I want to insert data into 3 tables with a single query.
My tables looks like below:
CREATE TABLE sample (
id bigserial PRIMARY KEY,
lastname varchar(20),
firstname varchar(20)
);
CREATE TABLE sample1(
user_id bigserial PRIMARY KEY,
sample_id bigint REFERENCES sample,
adddetails varchar(20)
);
CREATE TABLE sample2(
id bigserial PRIMARY KEY,
user_id bigint REFERENCES sample1,
value varchar(10)
);
I will get a key in return for every insertion and I need to insert that key in the next table.
My query is:
insert into sample(firstname,lastname) values('fai55','shaggk') RETURNING id;
insert into sample1(sample_id, adddetails) values($id,'ss') RETURNING user_id;
insert into sample2(user_id, value) values($id,'ss') RETURNING id;
But if I run single queries they just return values to me and I cannot reuse them in the next query immediately.
How to achieve this?
Use data-modifying CTEs:
WITH ins1 AS (
INSERT INTO sample(firstname, lastname)
VALUES ('fai55', 'shaggk')
-- ON CONFLICT DO NOTHING -- optional addition in Postgres 9.5+
RETURNING id AS sample_id
)
, ins2 AS (
INSERT INTO sample1 (sample_id, adddetails)
SELECT sample_id, 'ss' FROM ins1
RETURNING user_id
)
INSERT INTO sample2 (user_id, value)
SELECT user_id, 'ss2' FROM ins2;
Each INSERT depends on the one before. SELECT instead of VALUES makes sure nothing is inserted in subsidiary tables if no row is returned from a previous INSERT. (Since Postgres 9.5+ you might add an ON CONFLICT.)
It's also a bit shorter and faster this way.
Typically, it's more convenient to provide complete data rows in one place:
WITH data(firstname, lastname, adddetails, value) AS (
VALUES -- provide data here
('fai55', 'shaggk', 'ss', 'ss2') -- see below
, ('fai56', 'XXaggk', 'xx', 'xx2') -- works for multiple input rows
-- more?
)
, ins1 AS (
INSERT INTO sample (firstname, lastname)
SELECT firstname, lastname -- DISTINCT? see below
FROM data
-- ON CONFLICT DO NOTHING -- UNIQUE constraint? see below
RETURNING firstname, lastname, id AS sample_id
)
, ins2 AS (
INSERT INTO sample1 (sample_id, adddetails)
SELECT ins1.sample_id, d.adddetails
FROM data d
JOIN ins1 USING (firstname, lastname)
RETURNING sample_id, user_id
)
INSERT INTO sample2 (user_id, value)
SELECT ins2.user_id, d.value
FROM data d
JOIN ins1 USING (firstname, lastname)
JOIN ins2 USING (sample_id);
db<>fiddle here
You may need explicit type casts in a stand-alone VALUES expression - as opposed to a VALUES expression attached to an INSERT where data types are derived from the target table. See:
Casting NULL type when updating multiple rows
If multiple rows can come with identical (firstname, lastname), you may need to fold duplicates for the first INSERT:
...
INSERT INTO sample (firstname, lastname)
SELECT DISTINCT firstname, lastname FROM data
...
You could use a (temporary) table as data source instead of the CTE data.
It would probably make sense to combine this with a UNIQUE constraint on (firstname, lastname) in the table and an ON CONFLICT clause in the query.
Related:
How to use RETURNING with ON CONFLICT in PostgreSQL?
Is SELECT or INSERT in a function prone to race conditions?
Something like this
with first_insert as (
insert into sample(firstname,lastname)
values('fai55','shaggk')
RETURNING id
),
second_insert as (
insert into sample1( id ,adddetails)
values
( (select id from first_insert), 'ss')
RETURNING user_id
)
insert into sample2 ( id ,adddetails)
values
( (select user_id from first_insert), 'ss');
As the generated id from the insert into sample2 is not needed, I removed the returning clause from the last insert.
Typically, you'd use a transaction to avoid writing complicated queries.
http://www.postgresql.org/docs/current/static/sql-begin.html
http://dev.mysql.com/doc/refman/5.7/en/commit.html
You could also use a CTE, assuming your Postgres tag is correct. For instance:
with sample_ids as (
insert into sample(firstname, lastname)
values('fai55','shaggk')
RETURNING id
), sample1_ids as (
insert into sample1(id, adddetails)
select id,'ss'
from sample_ids
RETURNING id, user_id
)
insert into sample2(id, user_id, value)
select id, user_id, 'val'
from sample1_ids
RETURNING id, user_id;
You could create an after insert trigger on the Sample table to insert into the other two tables.
The only issue i see with doing this is that you wont have a way of inserting adddetails it will always be empty or in this case ss. There is no way to insert a column into sample thats not actualy in the sample table so you cant send it along with the innital insert.
Another option would be to create a stored procedure to run your inserts.
You have the question taged mysql and postgressql which database are we talking about here?
My database is using PostgreSQL. One table is using the serial auto-increment macro. If I want to insert a record into the table, do I still need to specify that value, or it is be automatically assigned for me?
CREATE TABLE dataset
(
id serial NOT NULL,
age integer NOT NULL,
name character varying(32) NOT NULL,
description text NOT NULL DEFAULT ''::text
CONSTRAINT dataset_pkey PRIMARY KEY (id)
);
Using the DEFAULT keyword or by omitting the column from the INSERT list:
INSERT INTO dataset (id, age, name, description)
VALUES (DEFAULT, 42, 'fred', 'desc');
INSERT INTO dataset (age, name, description)
VALUES (42, 'fred', 'desc');
If you create a table with a serial column then if you omit the serial column when you insert data into the table PostgreSQL will use the sequence automatically and will keep the order.
Example:
skytf=> create table test_2 (id serial,name varchar(32));
NOTICE: CREATE TABLE will create implicit sequence "test_2_id_seq" for serial column "test_2.id"
CREATE TABLE
skytf=> insert into test_2 (name) values ('a');
INSERT 0 1
skytf=> insert into test_2 (name) values ('b');
INSERT 0 1
skytf=> insert into test_2 (name) values ('c');
INSERT 0 1
skytf=> select * From test_2;
id | name
----+------
1 | a
2 | b
3 | c
(3 rows)
These query work for me:
insert into <table_name> (all columns without id serial)
select (all columns without id serial)
FROM <source> Where <anything>;
Inserting multiple rows wasn't working for me in this scenario:
create table test (
id bigint primary key default gen_id(),
msg text not null
)
insert into test (msg)
select gs
from generate_series(1,10) gs;
because I had mistakenly marked my gen_id function IMMUTABLE.
The insert query was being optimized to only call that function once rather than 10 times. Oops...
For example, you create "person" table with "id" of serial and "name" as shown below:
CREATE TABLE person (
id serial PRIMARY KEY,
name VARCHAR(50)
)
Then, you can use DEFAULT for "id" of serial and insert rows without column(field) names as shown below:
INSERT INTO person VALUES (DEFAULT, 'John'), (DEFAULT, 'Tom');
postgres=# SELECT * FROM person;
id | name
----+------
1 | John
2 | Tom
I'm trying to insert some data to a table contains two things : "a string" and "maximum number in Order column + 1".
This is my query:
INSERT INTO MyTable ([Text],[Order])
SELECT 'MyText' , (Max([Order]) + 1)
FROM MyTable
What is going wrong with my query?
I'm using Microsoft SQL Server 2005 SP3.
You can test this query like this:
I don't receive error:
create table #MyTable
(
[Text] varchar(40),
[Order] int NOT NULL
)
INSERT INTO #MyTable([Text],[Order])
SELECT 'MyText' [Text], isnull(max([order]) + 1, 0) [Order]
FROM #MyTable
drop table #MyTable
Original:
INSERT INTO MyTable ([Text],[Order])
SELECT 'MyText' [Text], max([Order]) + 1 [Order]
FROM MyTable
or
INSERT INTO MyTable ([Text],[Order])
SELECT top 1 'MyText' [Text], max([Order]) + 1 [Order]
FROM MyTable
limit is not valid in SQL Server as far as I know.
Cannot insert the value NULL into column 'Order', table 'master.dbo.MyTable'; column does not allow nulls. INSERT fails. The statement has been terminated.
This means that the Order column isn't allowed to be null, and that the Max([Order]) + 1 part of your column returns NULL.
This is because your table is empty, as you already noticed by yourself.
You can work around this by replacing NULL by a real number in the query, using ISNULL():
INSERT INTO MyTable ([Text],[Order])
SELECT 'MyText' , (isnull(Max([Order]),0) + 1)
FROM MyTable
Unless he has a column named OrderBy
then he would have to add / assign all values within that Insert especially if the column does not allow for nulls
sounds like fully qualifying the Insert with the dbo.MyTable.Field may make more sense.
also why are you naming fields with SQL Key words...???
INSERT INTO MyTable ([Text],[Order] Values('MyTextTest',1)
try a test insert first..