SQL Training 01

NoSQL

RBDMS

TRN

MDF

BAK

LDF

It uniquely identifies each row

It can contain NULL values

It can be composed of multiple columns

It automatically creates an index

WHERE

ORDER BY

TOP

The parent table contains the foreign key

The child table contains the foreign key

One record in the parent table can relate to multiple records in the child table

It requires a link table

Requires a link table

Each table can have multiple related rows in the other table

Not able to use constraints in their columns

INNER JOIN

LEFT JOIN

FULL OUTER JOIN

CROSS JOIN

INNER JOIN

LEFT JOIN

RIGHT JOIN

FULL OUTER JOIN

CROSS JOIN

INNER JOIN

LEFT JOIN

FULL OUTER JOIN

CROSS JOIN

Both are exact numeric types

FLOAT is approximate, REAL is exact

Both are approximate numeric types

REAL is used for integers only

CHAR is variable-length, VARCHAR is fixed-length

CHAR is fixed-length, VARCHAR is variable-length

Both are fixed-length

Both are variable-length

TEXT

NTEXT

IMAGE

NVARCHAR(MAX)

DATETIME

DATETIME2

SMALLDATETIME

TIME

Larger storage size compared to INT

Cannot be indexed

Fragmentation in clustered indexes

No default function to generate one in case of insert

FROM

WHERE

TOP

ORDER BY

SELECT * FROM Employees

SELECT ALL FROM Employees

SELECT Employees.* FROM Employees

SELECT * Employees

ORDER BY LastName, FirstName

ORDER BY LastName ASC, FirstName DESC

ORDER BY 1, 2

ORDER BY LastName AND FirstName

SELECT TOP 5 * FROM Employees

SELECT LIMIT 5 * FROM Employees

SELECT FIRST 5 * FROM Employees

SELECT * FROM Employees TOP 5