How to Create table in SQL with table level unique key with table level Identity Seed - sql-server-2012

Question

I want a table where Column1 and column2 must be unique along with auto Identity on Column1:
Ex:
Create table Foo (Id int, Name varchar(50));
Id column must be auto increment itself.
Data will passed like
A
A
B
B
Data to be inserted like below:
1 A
2 A
1 B
2 B
How can I achieve the same?

Answer 1

When you're using MySQL and can live with having a table with MyISAM engine, there's a built in functionality:
For MyISAM tables, you can specify AUTO_INCREMENT on a secondary
column in a multiple-column index. In this case, the generated value
for the AUTO_INCREMENT column is calculated as
MAX(auto_increment_column) + 1 WHERE prefix=given-prefix. This is
useful when you want to put data into ordered groups.
CREATE TABLE animals (
grp ENUM('fish','mammal','bird') NOT NULL,
id MEDIUMINT NOT NULL AUTO_INCREMENT,
name CHAR(30) NOT NULL,
PRIMARY KEY (grp,id)
) ENGINE=MyISAM;
INSERT INTO animals (grp,name) VALUES
('mammal','dog'),('mammal','cat'),
('bird','penguin'),('fish','lax'),('mammal','whale'),
('bird','ostrich');
SELECT * FROM animals ORDER BY grp,id;
Which returns:
+--------+----+---------+
| grp | id | name |
+--------+----+---------+
| fish | 1 | lax |
| mammal | 1 | dog |
| mammal | 2 | cat |
| mammal | 3 | whale |
| bird | 1 | penguin |
| bird | 2 | ostrich |
+--------+----+---------+
In this case (when the AUTO_INCREMENT column is part of a
multiple-column index), AUTO_INCREMENT values are reused if you delete
the row with the biggest AUTO_INCREMENT value in any group. This
happens even for MyISAM tables, for which AUTO_INCREMENT values
normally are not reused.
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