What is SQL Server

SQL Server is a relational database management system (RDBMS) from Microsoft that’s designed for the enterprise environment. SQL Server runs on T-SQL (Transact -SQL), a set of programming extensions from Sybase and Microsoft that add several features to standard SQL,

including transaction control, exception and error handling, row processing, and declared variables.

Code named Yukon in development, SQL Server 2005 was released in November 2005. The 2005 product is said to provide enhanced flexibility, scalability, reliability, and security to database applications, and to make them easier to create and deploy, thus reducing the complexity and tedium involved in database management. SQL Server 2005 also includes more administrative support.

The original SQL Server code was developed by Sybase; in the late 1980s, Microsoft, Sybase and Ashton-Tate collaborated to produce the first version of the product, SQL Server 4.2 for OS/2. Subsequently, both Sybase and Microsoft offered SQL Server products. Sybase has since renamed their product Adaptive Server Enterprise.

What can Sql Do.

• SQL can execute queries against a database
• SQL can retrieve data from a database
• SQL can insert records in a database
• SQL can update records in a database
• SQL can delete records from a database
• SQL can create new databases
• SQL can create new tables in a database
• SQL can create stored procedures in a database
• SQL can create views in a database
• SQL can set permissions on tables, procedures, and views

Sql Select Statement

The select command is the most important for most users. Its purpose is to retrieve data.

select * from table_name
or
select columnlist
from tablelist

Sql Distinct Statement

The SQL DISTINCT command used along with the SELECT keyword retrieves only unique data entries depending on the column list you have specified after it.

select distinct columnlist


from tablelist

Sql where Clause

The WHERE clause is used to extract only those records that fulfill a specified criterion.

select * from table_name

where column_name

or

select * from tablelist

where columnlist

Sql And & OR Operators

The AND operator displays a record if both the first condition and the second condition is true.

SELECT * FROM table_name

WHERE column_name

OR column_name

The OR operator displays a record if either the first condition or the second condition is true.

SELECT * FROM table_name

WHERE column_name

OR column_name

Combine use of AND & OR Operators

You can also combine AND and OR (use parenthesis to form complex expressions).


SELECT * FROM Persons WHERE

column_name

AND (column_name OR column_name)

Sql ORDER BY Keyword

The ORDER BY keyword is used to sort the result-set.


The ORDER BY keyword is used to sort the result-set by a specified column.

The ORDER BY keyword sort the records in ascending order by default.

If you want to sort the records in a descending order, you can use the DESC keyword.

SELECT column_name(s)


FROM table_name

ORDER BY column_name(s) ASC
DESC

Sql INSERT INTO Statement

The INSERT INTO statement is used to insert new records in a table.


There is two form of INSERT INTO statement.

The first form doesn’t specify the column names where the data will be inserted, only their values:-

INSERT INTO table_name

Values (Value 1,Value 2,Value 3,…..)

The second form specifies both the column names and the values to be inserted:-

INSERT INTO table_name

(column1, column2, column3,…)

Values (Value 1,Value 2,Value 3,…..)

Sql UPDATE statement

The UPDATE statement is used to update records in a table.


UPDATE table_name

SET column1=value, column2=value2,…

WHERE some_column=some_value

Sql DELETE Statement

The DELETE statement is used to delete records in a table.


DELETE FROM table_name

WHERE some_column=some_value

Sql ALL Commands

SQL Statement	Syntax
AND / OR	SELECT column_name(s)
	FROM table_name
	WHERE condition
	AND|OR condition
ALTER TABLE	ALTER TABLE table_name
	ADD column_name datatype
	or
	ALTER TABLE table_name
	DROP COLUMN column_name
AS (alias)	SELECT column_name AS column_alias
	FROM table_name
	or
	SELECT column_name
	FROM table_name AS table_alias
BETWEEN	SELECT column_name(s)
	FROM table_name
	WHERE column_name
	BETWEEN value1 AND value2
CREATE DATABASE	CREATE DATABASE database_name
CREATE TABLE	CREATE TABLE table_name
	(
	column_name1 data_type,
	column_name2 data_type,
	column_name2 data_type,
	...
	)
CREATE INDEX	CREATE INDEX index_name
	ON table_name (column_name)
	or
	CREATE UNIQUE INDEX index_name
	ON table_name (column_name)
CREATE VIEW	CREATE VIEW view_name AS
	SELECT column_name(s)
	FROM table_name
	WHERE condition
DELETE	DELETE FROM table_name
	WHERE some_column=some_value
	or
	DELETE FROM table_name
	(Note: Deletes the entire table!!)
	DELETE * FROM table_name
	(Note: Deletes the entire table!!)
DROP DATABASE	DROP DATABASE database_name
DROP INDEX	DROP INDEX table_name.index_name (SQL Server)
	DROP INDEX index_name ON table_name (MS Access)
	DROP INDEX index_name (DB2/Oracle)
	ALTER TABLE table_name
	DROP INDEX index_name (MySQL)
DROP TABLE	DROP TABLE table_name
GROUP BY	SELECT column_name, aggregate_function(column_name)
	FROM table_name
	WHERE column_name operator value
	GROUP BY column_name
HAVING	SELECT column_name, aggregate_function(column_name)
	FROM table_name
	WHERE column_name operator value
	GROUP BY column_name
	HAVING aggregate_function(column_name) operator value
IN	SELECT column_name(s)
	FROM table_name
	WHERE column_name
	IN (value1,value2,..)
INSERT INTO	INSERT INTO table_name
	VALUES (value1, value2, value3,....)
	or
	INSERT INTO table_name
	(column1, column2, column3,...)
	VALUES (value1, value2, value3,....)
INNER JOIN	SELECT column_name(s)
	FROM table_name1
	INNER JOIN table_name2
	ON table_name1.column_name=table_name2.column_name
LEFT JOIN	SELECT column_name(s)
	FROM table_name1
	LEFT JOIN table_name2
	ON table_name1.column_name=table_name2.column_name
RIGHT JOIN	SELECT column_name(s)
	FROM table_name1
	RIGHT JOIN table_name2
	ON table_name1.column_name=table_name2.column_name
FULL JOIN	SELECT column_name(s)
	FROM table_name1
	FULL JOIN table_name2
	ON table_name1.column_name=table_name2.column_name
LIKE	SELECT column_name(s)
	FROM table_name
	WHERE column_name LIKE pattern
ORDER BY	SELECT column_name(s)
	FROM table_name
	ORDER BY column_name [ASC|DESC]
SELECT	SELECT column_name(s)
	FROM table_name
SELECT *	SELECT *
	FROM table_name
SELECT DISTINCT	SELECT DISTINCT column_name(s)
	FROM table_name
SELECT INTO	SELECT *
	INTO new_table_name [IN externaldatabase]
	FROM old_table_name
	or
	SELECT column_name(s)
	INTO new_table_name [IN externaldatabase]
	FROM old_table_name
SELECT TOP	SELECT TOP number|percent column_name(s)
	FROM table_name
TRUNCATE TABLE	TRUNCATE TABLE table_name
UNION	SELECT column_name(s) FROM table_name1
	UNION
	SELECT column_name(s) FROM table_name2
UNION ALL	SELECT column_name(s) FROM table_name1
	UNION ALL
	SELECT column_name(s) FROM table_name2
UPDATE	UPDATE table_name
	SET column1=value, column2=value,...
	WHERE some_column=some_value
WHERE	SELECT column_name(s)
	FROM table_name
	WHERE column_name operator value