How do I ensure about non negative column?

Question

I need to create a table Branch with columns branch_name and branch_city character type, assets as integer type. branch_name is the primary key and I have to ensure that assets are non negative.

I tried like

CREATE TABLE Branch
(
    branch_name navarchar(100) primary key,
    branch_city nvarchar(100),
    assests int NOT NULL
)

Answer 1

You need to define a datatype for your primary key, and you need to add a CHECK constraint to ensure assets is non-negative:

CREATE TABLE dbo.Branch
(
    branch_name NVARCHAR(100) primary key,
    branch_city nvarchar(100),
    assets int NOT NULL CHECK (assets >= 0)
)

Answer 2

Alter your table creating a constraint to check the column

ALTER TABLE Branch ADD CONSTRAINT chkassets CHECK (assets > 0);