select

how to return upto 3 rows
SELECT * FROM Customers
WHERE ROWNUM <= 3;
SELECT * FROM Customers
LIMIT 3;
SELECT TOP 3 * FROM Customers;	SELECT TOP 50 PERCENT * FROM Customers;
	WHERE Country='Germany';
	WHERE Country='Germany'
	LIMIT 3;
SELECT MIN(Price) AS SmallestPrice
FROM Products;

SELECT MAX(Price) AS LargestPrice	write largets price
FROM Products;	number
SELECT COUNT(column_name)	find how many rows
FROM table_name
WHERE condition;
SELECT AVG(column_name)	find avg of that row
FROM table_name
WHERE condition;
SELECT SUM(column_name)
FROM table_name
WHERE condition;
like
SELECT column1, column2, ...
FROM table_name
WHERE columnN LIKE pattern;
WHERE CustomerName LIKE 'a%'	Finds any values that start with "a"
WHERE CustomerName LIKE '%a'	Finds any values that end with "a"
WHERE CustomerName LIKE '%or%'	Finds any values that have "or" in any position
WHERE CustomerName LIKE '_r%'	Finds any values that have "r" in the second position
WHERE CustomerName LIKE 'a_%'	Finds any values that start with "a" and are at least 2 characters in length
WHERE CustomerName LIKE 'a__%'	Finds any values that start with "a" and are at least 3 characters in length
WHERE ContactName LIKE 'a%o'	Finds any values that start with "a" and ends with "o"
SELECT * FROM Customers
WHERE CustomerName NOT LIKE 'a%';
any thing is matched that will display
SELECT * FROM Customers
WHERE Country IN ('Germany', 'France', 'UK');
SELECT column_name(s)
FROM table_name
WHERE column_name IN (SELECT STATEMENT);
ist it will select suplieers table then it from tha t we got country so it will  if any country is matched in anohter table that will display
SELECT * FROM Customers
WHERE Country IN (SELECT Country FROM suppliers);
between
SELECT * FROM Products	11,12,13,14--19
WHERE Price BETWEEN 10 AND 20;	any nyumber is matched it will display
SELECT CustomerID AS ID, CustomerName AS Customer
FROM Customers;	change the column header names
SELECT CustomerName AS Customer, ContactName AS [Contact Person]	if name contan space requure brackets or double quotationif the alis contain spaces like contac and person some space is ther
FROM Customers;

SELECT CustomerName, Address + ', ' + PostalCode + ' ' + City + ', ' + Country AS Address

FROM Customers;

select * from customers