auto-increment

I am using Room persistent library. I have requirement to add two primary keys in one table and one of the primary key should be auto increment. I don't know exact syntax to achieve this. Below is my Model class: @Entity(tableName = "newsPapers", primaryKeys = {"news_paper_id","news_paper_name"}) public class SelectNewsModel { private int news_paper_id; @ColumnInfo(name = "image_url") private String imageUrl; @ColumnInfo(name = "news_paper_name") private String newsPaperName; } I want to make "news_paper_id" to be auto incremented. How can i make it? I found another way around for this problem

Basically I want to use uniqueidentifier in similar way as identity. I don't want to insert values into it, It should just insert values automatically, different value for each row. I'm not able to set autoincrement on columns of type uniqueidentifier(the property 'autoincrement' is set to false and is not editable). Or even better: use the newsequentialid() as the default for your UNIQUEIDENITIFER column. That'll give you a somewhat sequential series of GUIDs. CREATE TABLE dbo.YourTable (SerialID UNIQUEIDENTIFIER CONSTRAINT DF_SerialID DEFAULT newsequentialid(), .... (other columns)...... )

How do I add auto_increment to an existing column of a MySQL table? Don Kirkby I think you want to MODIFY the column as described for the ALTER TABLE command . It might be something like this: ALTER TABLE users MODIFY id INTEGER NOT NULL AUTO_INCREMENT; Before running above ensure that id column has a Primary index. Arian Acosta Method to add AUTO_INCREMENT to a table with data while avoiding “ Duplicate entry ” error: Make a copy of the table with the data using INSERT SELECT: CREATE TABLE backupTable LIKE originalTable; INSERT backupTable SELECT * FROM originalTable; Delete data from

I have the following table in postgres: CREATE TABLE "test" ( "id" serial NOT NULL PRIMARY KEY, "value" text ) I am doing following insertions: insert into test (id, value) values (1, 'alpha') insert into test (id, value) values (2, 'beta') insert into test (value) values ('gamma') In the first 2 inserts I am explicitly mentioning the id. However the table's auto increment pointer is not updated in this case. Hence in the 3rd insert I get the error: ERROR: duplicate key value violates unique constraint "test_pkey" DETAIL: Key (id)=(1) already exists. I never faced this problem in Mysql in both

I have an database that is rapidly filled with data we talk about 10-20k rows per day. What is a limit of an ID with and autoincrement option? If ID is created as INTEGER then I can do max value of 2,147,483,647 for unsigned values? But what when autoincrement goes above this? Does it all collapses? What would be solution then? I am sure that a lot of people have big databases, and I would like to hear them. Thank you. If you are worried about it growing out of bounds too quickly, I would set the PK as an UNSIGNED BIGINT. That gives you a max value of 18446744073709551615, which should be

I'm currently building a project which involves a lot of collective intelligence. Every user visiting the web site gets created a unique profile and their data is later used to calculate best matches for themselves and other users. By default, Django creates an INT(11) id field to handle models primary keys. I'm concerned with this being overflown very quickly (i.e. ~2.4b devices visiting the page without prior cookie set up). How can I change it to be represented as BIGINT in MySQL and long() inside Django itself? I've found I could do the following ( http://docs.djangoproject.com/en/dev/ref

I'm new at postgres (and at database info systems all in all). I ran following sql script on my database: create table cities ( id serial primary key, name text not null ); create table reports ( id serial primary key, cityid integer not null references cities(id), reportdate date not null, reporttext text not null ); create user www with password 'www'; grant select on cities to www; grant insert on cities to www; grant delete on cities to www; grant select on reports to www; grant insert on reports to www; grant delete on reports to www; grant select on cities_id_seq to www; grant insert on

I am currently using MySQL. I have a table that has an auto_increment 'id' field, and an 'imgname' field containing a string that is the file name of an image. I need to generate the 'imgname' value using the auto_increment value that is create by an INSERT INTO statement. The problem is, I don't know this value until I can use mysql_insert_id, AFTER the insert query has run. I would like to know if it's possible to access this value DURING the insert query somehow and then use it to generate my string in the query statement. Thanks in advance. I would keep the id and imgname independent of

i am working with HSQL database for testing purpose. i want standalone db file. but now i am in trouble to get last inserted row id (auto-incremental - identity) in HSQL. how can i get id?? It's pretty hard to write a query to perform this when you haven't given your table schema, but something like the following: SELECT TOP 1 Id FROM [TABLENAME] ORDER BY Id DESC http://www.hsqldb.org/doc/guide/ch09.html the last inserted value into an identity column for a connection is available using the function IDENTITY(), for example (where Id is the identity column): INSERT INTO Test (Id, Name) VALUES

MySQL doesn't support multiple auto increment columns. CREATE TABLE IF NOT EXISTS `parts` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `order` int(11) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ; Is there another solution to make the value of column order increase automatically when I insert a new record? You can do it from within your application by issuing another query that increases order or you can create a trigger that does that for you. Whatever you do, for the sake of sanity of programming world - don't use reserved