I want to insert (user_id) value from a select statement like below without identity column. Currently this query doesn't follow the sequence number in order. Kindly advise.
https://dbfiddle.uk/?rdbms=oracle_18&fiddle=195728e48cc8a5a0047fec8837e9f217
This is answering the original version of the question.
If you are asking can you have identical SQL statements to use a sequence in SQL Server and in Oracle then, no, you cannot.
In Oracle, the syntax is:
INSERT INTO b_user ( user_id /*, ... */ )
VALUES ( b_user__user_id__seq.NEXT_VAL /*, ... */ );
In SQL Server, the syntax is:
INSERT INTO b_user ( user_id /*, ... */ )
VALUES ( NEXT VALUE FOR b_user__user_id__seq /*, ... */ );
In Oracle, you could wrap the call to the sequence in a function:
CREATE FUNCTION get_next_b_user_id RETURN INT
IS
BEGIN
RETURN b_user__user_id__seq.NEXTVAL;
END;
/
Then you could use:
INSERT INTO b_user ( user_id /*, ... */ )
VALUES ( get_next_b_user__id__seq() /*, ... */ );
However, in SQL server you cannot use a sequence in user-defined functions so that approach in Oracle cannot be replicated.
So, in short, you are going to have to use different SQL statements for the different databases if you are using a sequence.
If you want to use an IDENTITY column then you can get the same syntax in both.
In Oracle:
CREATE TABLE b_user (
user_id INT
GENERATED ALWAYS AS IDENTITY,
user_name VARCHAR(250),
user_email VARCHAR(250),
user_address VARCHAR(250),
user_city VARCHAR(50),
user_state VARCHAR(5),
user_country VARCHAR(5),
user_zip VARCHAR(10)
);
and in SQL Server:
CREATE TABLE b_user (
user_id INT IDENTITY(1,1),
user_name VARCHAR(250),
user_email VARCHAR(250),
user_address VARCHAR(250),
user_city VARCHAR(50),
user_state VARCHAR(5),
user_country VARCHAR(5),
user_zip VARCHAR(10)
)
Then, in both databases, you can use the statement:
insert into b_user (
user_name,
user_email,
user_address,
user_city,
user_state,
user_country,
user_zip
) values (
'Alice',
'alice#example.com',
'A house',
'A city',
'STATE',
'ABC',
'ZZ0123'
);
Oracle db<>fiddle and SQL Server db<>fiddle
one option is, if you know know that the column user_id has some values already inserted then when you create a sequence which you are going to use for that column
--example you start with 3 if you know 2 is the maximum value for that column.
CREATE SEQUENCE b_user__user_id__seq start with 3 ;
It is better to have a primary key or unique constraint in that column.
Related
I'm coming from a Teradata environment where
create table mytable
(
first_column varchar(50),
second_column varchar(50),
third_column varchar(50)
)
insert into mytable values (first_column = 'one', second_column = 'first')
insert into mytable values (first_column = 'two', third_column = 'second')
is possible. This does not seem to be possible in HANA even with default specified
create column table mytable
(
"FIRST_COLUMN" varchar(50) default null,
"SECOND_COLUMN" varchar(50) default null,
"THIRD_COLUMN" varchar(50) default null
)
I could create a row with a unique ID specifying NULLs for all the fields and then UPDATE the columns I want using the ID which seems time consuming and awkward or is there a better way?
Use the standard syntax:
insert into mytable (first_column, second_column)
values ('one', 'first');
This should work both in Hana and Teradata -- and any other database.
I'm trying to get a distinct row using SQL from set of records that have matching key/id value, but NULLs in different columns. Hard to explain so please see screenshot. Any ideas?
create temporary table my_table (
id varchar(30), segmentdate1 date, converted1 varchar(10), segmentdate2 date, converted2 varchar(10)
);
insert into my_table (
id, segmentdate1, converted1, segmentdate2, converted2
)
values
('Michael','9/15/2020','No',NULL,NULL),
('Michael',NULL,NULL,'7/1/2019','Yes')
;
You seem to want aggregation:
select id, max(segmentdate1) as segmentdate1, max(converted1) as converted1,
max(segmentdate2) as segmentdate2, max(converted2) as converted2
from t
group by id;
Note: I made up names for the columns so they are unique.
This is probably a result set created from another query. That query probably has the wrong group by keys. You should probably fix that query.
declare #my_table table (
id varchar(30), segmentdate1 date, converted1 varchar(10), segmentdate2 date, converted2 varchar(10)
);
insert into #my_table (
id, segmentdate1, converted1, segmentdate2, converted2
)
values
('Michael','9/15/2020','No',NULL,NULL),
('Michael',NULL,NULL,'7/1/2019','Yes')
;
select id,max(isnull(segmentdate1,'1200-01-01')) segmentdate2
,max(isnull(converted1,'')) converted1, max(isnull(segmentdate2,'1200-01-01')) segmentdate2
,max(isnull(converted2,'')) converted2
from #my_table
group by id
I am implementing a library management system in SQL. I have the following table structure and some values inserted in them:
create table books
(
IdBook number(5),
NameBook varchar2(35),
primary key(IdBook)
);
create table users
(
IdUsers number(5),
NameUser varchar2(20),
primary key(IdUsers)
);
create table borrowed
(
IdBorrowed number(5),
IdUsers number(5),
IdBook number(5),
DueDate date,
DateReturned date,
constraint fk_borrowed foreign key(IdUsers) references users(IdUsers),
constraint fk_borrowed2 foreign key(IdBook) references books(IdBook)
);
insert into books values(0,'FairyTale');
insert into books values(1,'Crime and Punishment');
insert into books values(2,'Anna Karenina');
insert into books values(3,'Norwegian Wood');
insert into users values(01,'Robb Dora');
insert into users values(02,'Pop Alina');
insert into users values(03,'Grozavescu Teodor');
insert into users values(04,'Popa Alin');
insert into borrowed values(10,02,3,'22-Jan-2017',null);
insert into borrowed values(11,01,1,'25-Jan-2017','19-Dec-2016');
insert into borrowed values(12,01,3,'22-Jan-2017',null);
insert into borrowed values(13,04,2,'22-Jan-2017','13-Dec-2016');
What I want now is that my db to allow "borrowing" books for the users(i.e insert into the borrowed table) that have no unreturned books(i.e date returned is not null) and if they have unreturned books I want to abandon the whole process. I thought to implement this in the following way:
create or replace procedure borrowBook(IdBorrowed in number,IdUsers number,IdBook number,DueDate date,DateReturned date) as begin
if exists (SELECT u.IdUsers, u.NameUser, b.DateReturned
FROM users u, borrowed b
WHERE u.IDUSERS = b.IdUsers and DateReturned is not null),
insert into borrowed values(IdBorrowed,IdUsers,IdBook,DueDate,DateReturned);
end borrowBook;
The above procedure does not check if the parameter I pass to this function is the same as the one in my select and I do not know how to do this and correctly insert a value in my table.
Any help would be much appreciated. Thank in advance!
You should not name your parameters the same as columns also used inside the procedure.
You can also simplify your procedure to a single INSERT statement, no IF required:
create or replace procedure borrowBook(p_idborrowed in number, p_idusers number, p_idbook number, p_duedate date, p_datereturned date)
as
begin
insert into borrowed (idborrowed, idusers, idbook, duedate, datereturned)
select p_idborrowed, p_idusers, p_idbook, p_duedate, p_datereturned
from dual
where not exists (select *
from users u
join borrowed b on u.idusers = b.idusers
and b.datereturned is not null);
end borrowBook;
It's also good coding style to explicitly list the columns for an INSERT statement. And you should get used to the explicit JOIN operator instead of using implicit joins in the where clause.
What about this one:
create or replace procedure borrowBook( p_IdBorrowed in number ,
p_IdUsers number ,
p_IdBook number ,
p_DueDate date ,
p_DateReturned date )
as
begin
if (SELECT COUNT(*)
FROM borrowed
WHERE IDUSERS = p_IdUsers
AND DateReturned IS NULL) = 0 THEN
insert into borrowed values (p_IdBorrowed ,
p_IdUsers ,
p_IdBook ,
p_DueDate ,
p_DateReturned );
end if ;
end borrowBook;
You would seem to want something like this:
create or replace procedure borrowBook (
in_IdBorrowed in number,
in_IdUsers number,
in_IdBook number,
in_DueDate date,
in_DateReturned date
) as
v_flag number;
begin
select (case when exists (select 1
from borrowed b
where b.IdUsers = in_IdUsers and b.DateReturned is not null
)
then 1 else 0
end)
into v_flag
from dual;
if (flag = 0) then
insert into borrowed
values(in_IdBorrowed, in_IdUsers, in_IdBook, in_DueDate, v_DateReturned);
end if
end -- borrowBook;
I would like to take some data from a table from DB1 and insert some of that data to a table in DB2.
How would one proceed to do this?
This is what I've got so far:
CREATE VIEW old_study AS
SELECT *
FROM dblink('dbname=mydb', 'select name,begins,ends from study')
AS t1(name varchar(50), register_start date, register_end date);
/*old_study now contains the data I wanna transfer*/
INSERT INTO studies VALUES (nextval('studiesSequence'),name, '',3, 0, register_start, register_end)
SELECT name, register_start, register_end from old_study;
This is how my table in DB2 looks:
CREATE TABLE studies(
id int8 PRIMARY KEY NOT NULL,
name_string VARCHAR(255) NOT NULL,
description VARCHAR(255),
field int8 REFERENCES options_table(id) NOT NULL,
is_active INTEGER NOT NULL,
register_start DATE NOT NULL,
register_end DATE NOT NULL
);
You should include the column names in both the insert and select:
insert into vip_employees(name, age, occupation)
select name, age, occupation
from employees;
However, your data structure is suspect. Either you should use a flag in employees to identify the "VIP employees". Or you should have a primary key in employees and use this primary key in vip_employees to refer to employees. Copying over the data fields is rarely the right thing to do, especially for columns such as age which are going to change over time. Speaking of that, you normally derive age from the date of birth, rather than storing it directly in a table.
INSERT INTO studies
(
id
,name_string
,description
,field
,is_active
,register_start
,register_end
)
SELECT nextval('studiesSequence')
,NAME
,''
,3
,0
,register_start
,register_end
FROM dblink('dbname=mydb', 'select name,begins,ends from study')
AS t1(NAME VARCHAR(50), register_start DATE, register_end DATE);
You can directly insert values that retured by dblink()(that means no need to create a view)
Loop and cursor are weapons of last resort. Try to avoid them. You probably want INSERT INTO ... SELECT:
INSERT INTO x(x, y, z)
SELECT x, y, z
FROM t;
SqlFiddleDemo
EDIT:
INSERT INTO vip_employees(name, age, occupation) -- your column list may vary
SELECT name, age, occupation
FROM employees;
Your syntax is wrong. You cannot have both, a values clause for constant values and a select clause for a query in your INSERT statement.
You'd have to select constant values in your query:
insert into studies
(
id,
name_string,
description,
field,
is_active,
register_start,
register_end
)
select
studiesSequence.nextval,
name,
'Test',
null,
0,
register_start,
register_end
from old_study;
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?