Sql basics 2

Non-correlated Sub query
USE AdventureWorks
SELECT SalesPersonID,
SalesQuota CurrentSalesQuota
FROM Sales.SalesPerson
WHERE SalesQuota IN
(SELECT MAX(SalesQuota)
FROM Sales.SalesPerson)

UNION
USE AdventureWorks
SELECT SalesPersonID, GETDATE() QuotaDate,
SalesQuota FROM Sales.SalesPerson
WHERE SalesQuota > 0
UNION
SELECT SalesPersonID, QuotaDate, SalesQuota
FROM Sales.SalesPersonQuotaHistory
WHERE SalesQuota > 0
ORDER BY SalesPersonID DESC, QuotaDate DESC

Combining Result Sets
with UNION
•The UNION operator is used to append the results of two or
more SELECT statements into a single result set
•Each SELECT statement being merged must have the same
number of columns, with the same or compatible data types
in the same order

Table Valued Function
USE AdventureWorks
GO
CREATE FUNCTION dbo.fn_WorkOrderRouting
(@WorkOrderID int) RETURNS TABLE
AS
RETURN
SELECT WorkOrderID,ProductID,OperationSequence,LocationID
FROM Production.WorkOrderRouting
WHERE WorkOrderID = @WorkOrderID
GO

Using CROSS APPLY
USE AdventureWorks
GO
SELECT
w.WorkOrderID,w.OrderQty,r.ProductID,r.OperationSequence
FROM Production.WorkOrder w
CROSS APPLY dbo.fn_WorkOrderRouting
(w.WorkOrderID) AS r
ORDER BY w.WorkOrderID,w.OrderQty,r.ProductID

APPLY
•APPLY is used to invoke a table-valued function for each row
of an outer query
•CROSS APPLY works like an INNER JOIN in that unmatched
rows between the left table and the table-valued function
don’t appear in the result set
•OUTER APPLY is like an OUTER JOIN, in that mismatched
rows are still returned in the result set with NULL values in
the function results.

EXCEPT and INTERCEPT
-- First two new tables based on ProductionProduct will be created
USE AdventureWorks
GO
SELECT prod.ProductID,
prod.Name
INTO dbo.TableA
FROM
(SELECT ProductID,
Name,
ROW_NUMBER() OVER (ORDER BY ProductID) RowNum
FROM Production.Product) prod

Create second table
USE AdventureWorks
GO
-- Create TableB
SELECT prod.ProductID,
prod.Name
INTO dbo.TableB
FROM
(SELECT ProductID,
Name,
ROW_NUMBER() OVER (ORDER BY ProductID) RowNum
FROM Production.Product) prod
WHERE RowNum BETWEEN 10 and 29

EXCEPT
USE AdventureWorks
GO
SELECT ProductID,
Name
FROM TableA
EXCEPT
SELECT ProductID,
Name
FROM TableB

INTERSECT
USE AdventureWorks
GO
SELECT ProductID,Name
FROM TableA
INTERSECT
SELECT ProductID,Name
FROM TableB

CUBE
USE AdventureWorks
GO
SELECT i.Shelf,
SUM(i.Quantity) Total
FROM Production.ProductInventory i
GROUP BY i.Shelf
WITH CUBE

What is CUBE ?
•WITH CUBE is used to aggregate values for each
grouping combination
•WITH CUBE is often used for reporting purposes,
providing an easy method of reporting totals by
grouped column

GROUPING with CUBE
USE AdventureWorks
GO
SELECT i.Shelf,
GROUPING(i.Shelf) Source,
SUM(i.Quantity) Total
FROM Production.ProductInventory i
GROUP BY i.Shelf
WITH CUBE

ROLLUP
USE AdventureWorks
GO
SELECT i.Shelf, p.Name,
SUM(i.Quantity) Total FROM Production.ProductInventory i
INNER JOIN Production.Product p ON
i.ProductID = p.ProductID
GROUP BY i.Shelf, p.Name
WITH ROLLUP

What is ROLLUP ?
WITH ROLLUP is used in conjunction with GROUP BY to add
hierarchical data summaries based on the ordering of
columns in the GROUP BY clause

HINTS
•SQL Server’s query optimization process is
responsible for producing a query execution plan when
a SELECT query is executed
•Under rare circumstances SQL Server may choose an
inefficient plan over a more efficient one
•After researching the query performance, you may
decide to override the decision making process of the
SQL Server query optimizer by using hints

JOINT Hints
A join hint will force the query optimizer to join the
tables in the way you command

JOIN without hint
USE AdventureWorks
GO
SET SHOWPLAN_TEXT ON
GO
SELECT p.Name,r.ReviewerName,r.Rating
FROM Production.Product p
INNER JOIN Production.ProductReview r ON
r.ProductID = p.ProductID
GO
SET SHOWPLAN_TEXT OFF
GO

JOIN with hint
USE AdventureWorks
GO
SET SHOWPLAN_TEXT ON
GO
SELECT p.Name,r.ReviewerName,
r.Rating
FROM Production.Product p
INNER HASH JOIN Production.ProductReview r ON
r.ProductID = p.ProductID
GO
SET SHOWPLAN_TEXT OFF
GO

Query with hint
USE AdventureWorks
GO
SELECT SalesOrderID,
ProductID,
UnitPrice,
OrderQty
FROM Sales.SalesOrderDetail
WHERE CarrierTrackingNumber = '5CE9-4D75-8F'
ORDER BY SalesOrderID,
ProductID
OPTION (RECOMPILE)

Table hint
USE AdventureWorks
GO
SELECT DocumentID,
Title
FROM Production.Document
WITH (NOLOCK)
WHERE Status = 1

Sql basics 2

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