Creating and populating a table in T-SQL - sql

Question

I'm new to T-SQL and trying to learn how to create a script in T-SQL to create and populate a table(StaffData).The StaffData is defined as below:
staffid – integer primary key, identity starting at 1, increments by 1
managerid – int, allows nulls, pointer to another record in managertable
name – string of 50 characters
salary – money
What can I do to generate table and fill it with set of data..?

Answer 1

Here's the correct SQL. I've tested it (just spotted that you want managerId nullable - I've added this):
it uses better conventions for your table and column names (you shouldn't be using 'data' in table names - we know it contains data)
it names your primary key constraints, which is better practice - you can do something similar for the FK constraint if you want, I've just done it inline
it uses 'USE' and 'GO' statements to ensure you're creating things on the right database (critical when you're working on big production systems).
it uses nvarchar columns - you need these to reliably store data from international character sets (e.g the manager has a Russian name)
I'm using nvarchar(max) as you can't be sure that a name will only be 50 characters. Use nvarchar(50) if you must, but database space isn't usually a big deal.
You need to create the Manager table first, as your Staff table depends on it:
USE [yourDatabaseName] -- you don't need the square brackets, but they don't hurt
-- Create ManagerTable
CREATE TABLE Manager
(
id int IDENTITY(1,1),
name nvarchar(max),
CONSTRAINT pk_manager PRIMARY KEY (id)
)
CREATE TABLE Staff
(
id int IDENTITY(1,1),
name nvarchar(max),
salary money,
managerId int FOREIGN KEY REFERENCES Manager(id) NULL,
CONSTRAINT pk_staff PRIMARY KEY (id)
)
--To populate Manager table:
INSERT INTO [Manager]
(
-- id column value is auto-generated
name
)
VALUES
(
'John Doe'
)
--To populate Staff table:
INSERT INTO [Staff]
(
-- id column value is auto-generated
name, salary, managerId
)
VALUES
(
'Jane Doe', 60000, 1
)
GO

Answer 2

To create the two database tables:
-- Create StaffData
CREATE TABLE StaffData
(
staffid int PRIMARY KEY IDENTITY,
managerid int
)
-- Create ManagerTable
CREATE TABLE ManagerTable
(
managerid int,
name varchar(50),
salary money
)
To populate StaffData table:
INSERT INTO [StaffData]
(
--staffid - this column value is auto-generated
[managerid]
)
VALUES
(
-- staffid - int
12345 -- managerid - int
)
To populate ManagerTable table:
INSERT INTO [ManagerTable]
(
[managerid],
[name],
[salary]
)
VALUES
(
12345, -- managerid - int
'Juan Dela Cruz', -- name - varchar
15000 -- salary - money
)
To select the data if i understand you in your word Pointer here is the query using INNER JOIN joining the two tables using their managerid
SELECT *
FROM [StaffData]
INNER JOIN [ManagerTable]
ON [StaffData].managerid = [ManagerTable].managerid