primary-key

I basically want to convert a table from mysql to sqlite with the following scheme: create table items ( id integer auto_increment, version integer default 0, primary key (id, version) ); Essentially, I want ID to auto increment whenever I insert anything into the table, with VERSION starting off at 0, but still allow multiple items with the same ID as long as VERSION is different. I'm trying to replicate this behavior with Sqlite however, I can't seem to get table creation working. It seems like you are only allowed one column as autoincrement and it has to be the primary key. If I make ID

In PostgreSQL, it is possible to put RETURNING at the end of an INSERT statement to return, say, the row's primary key value when that value is automatically set by a SERIAL type. Question: How do I store this value in a variable that can be used to insert values into other tables? Note that I want to insert the generated id into multiple tables. A WITH clause is, as far as I understand, only useful for a single insert. I take it that this will probably have to be done in PHP. This is really the result of bad design; without a natural key, it is difficult to grab a unique row unless you have a

I use postgresql 9.3, Ruby 2.0, Rails 4.0.0. After reading numerous questions on SO regarding setting the Primary key on a table, I generated and added the following migration: class CreateShareholders < ActiveRecord::Migration def change create_table :shareholders, { id: false, primary_key: :uid } do |t| t.integer :uid, limit: 8 t.string :name t.integer :shares t.timestamps end end end I also added self.primary_key = "uid" to my model. The migration runs successfully, but when I connect to the DB using pgAdmin III I see that the uid column is not set as primary key. What am I missing?

I have created a sqlite database using pandas df.to_sql however accessing it seems considerably slower than just reading in the 500mb csv file. I need to: set the primary key for each table using the df.to_sql method tell the sqlite database what datatype each of the columns in my 3.dataframe are? - can I pass a list like [integer,integer,text,text] code.... (format code button not working) if ext == ".csv": df = pd.read_csv("/Users/data/" +filename) columns = df.columns columns = [i.replace(' ', '_') for i in columns] df.columns = columns df.to_sql(name,con,flavor='sqlite',schema=None,if

I have the following table (PostgreSQL 8.3) which stores prices of some products. The prices are synchronised with another database, basically most of the fields below (apart from one) are not updated by our client - but instead dropped and refreshed every once-in-a-while to sync with another stock database: CREATE TABLE product_pricebands ( template_sku varchar(20) NOT NULL, colourid integer REFERENCES colour (colourid) ON DELETE CASCADE, currencyid integer NOT NULL REFERENCES currency (currencyid) ON DELETE CASCADE, siteid integer NOT NULL REFERENCES site (siteid) ON DELETE CASCADE, master

I'm trying to understand a concept rather than fixing a piece of code that won't work. I'll take a general example of a form (parent table) and a form field (child table). Logically , this would be an identifying relationship, since a form field cannot exist without a form. This would make me think that in order to translate the logical relationship into the technical relationship, a simple NOT NULL for the form_id field in the form_field table would suffice. (See the left part of above screenshot.) However, when I add an identifying relationship using MySQL Workbench, form_id is not only NOT

How to add composite primary keys in SQL Server 2008? I have a table as follows. testRequest (wardNo nchar(5) , BHTNo nchar(5) , testID nchar(5) , reqDateTime datetime); I need wardNo, BHTNo and testID to be a composite primary key. How can I do this in SQL Server Management Studio? MaDu_LK If you use management studio, simply select the wardNo, BHTNo, testID columns and click on the key mark in the toolbar. Command for this is, ALTER TABLE dbo.testRequest ADD CONSTRAINT PK_TestRequest PRIMARY KEY (wardNo, BHTNo, TestID) How about this: ALTER TABLE dbo.testRequest ADD CONSTRAINT PK_TestRequest