SELECT Examples (Transact-SQL)
This topic provides examples of using the SELECT statement.
A. Using SELECT to retrieve rows and columns
The following example shows three code examples. This first code example returns all rows (no WHERE clause is specified) and all columns (using the *) from the Product table in the AdventureWorks2012 database.
USE AdventureWorks2012;
GO
SELECT *
FROM Production.Product
ORDER BY Name ASC;
-- Alternate way.
USE AdventureWorks2012;
GO
SELECT p.*
FROM Production.Product AS p
ORDER BY Name ASC;
GO
This example returns all rows (no WHERE clause is specified), and only a subset of the columns (Name, ProductNumber, ListPrice) from the Product table in the AdventureWorks2012 database. Additionally, a column heading is added.
USE AdventureWorks2012;
GO
SELECT Name, ProductNumber, ListPrice AS Price
FROM Production.Product
ORDER BY Name ASC;
GO
This example returns only the rows for Product that have a product line of R and that have days to manufacture that is less than 4.
USE AdventureWorks2012;
GO
SELECT Name, ProductNumber, ListPrice AS Price
FROM Production.Product
WHERE ProductLine = 'R'
AND DaysToManufacture < 4
ORDER BY Name ASC;
GO
B. Using SELECT with column headings and calculations
The following examples return all rows from the Product table. The first example returns total sales and the discounts for each product. In the second example, the total revenue is calculated for each product.
USE AdventureWorks2012;
GO
SELECT p.Name AS ProductName,
NonDiscountSales = (OrderQty * UnitPrice),
Discounts = ((OrderQty * UnitPrice) * UnitPriceDiscount)
FROM Production.Product AS p
INNER JOIN Sales.SalesOrderDetail AS sod
ON p.ProductID = sod.ProductID
ORDER BY ProductName DESC;
GO
This is the query that calculates the revenue for each product in each sales order.
USE AdventureWorks2012;
GO
SELECT 'Total income is', ((OrderQty * UnitPrice) * (1.0 - UnitPriceDiscount)), ' for ',
p.Name AS ProductName
FROM Production.Product AS p
INNER JOIN Sales.SalesOrderDetail AS sod
ON p.ProductID = sod.ProductID
ORDER BY ProductName ASC;
GO
C. Using DISTINCT with SELECT
The following example uses DISTINCT to prevent the retrieval of duplicate titles.
USE AdventureWorks2012;
GO
SELECT DISTINCT JobTitle
FROM HumanResources.Employee
ORDER BY JobTitle;
GO
D. Creating tables with SELECT INTO
The following first example creates a temporary table named #Bicycles in tempdb.
USE tempdb;
GO
IF OBJECT_ID (N'#Bicycles',N'U') IS NOT NULL
DROP TABLE #Bicycles;
GO
SELECT *
INTO #Bicycles
FROM AdventureWorks2012.Production.Product
WHERE ProductNumber LIKE 'BK%';
GO
This second example creates the permanent table NewProducts.
USE AdventureWorks2012;
GO
IF OBJECT_ID('dbo.NewProducts', 'U') IS NOT NULL
DROP TABLE dbo.NewProducts;
GO
ALTER DATABASE AdventureWorks2012 SET RECOVERY BULK_LOGGED;
GO
SELECT * INTO dbo.NewProducts
FROM Production.Product
WHERE ListPrice > $25
AND ListPrice < $100;
GO
ALTER DATABASE AdventureWorks2012 SET RECOVERY FULL;
GO
E. Using correlated subqueries
The following example shows queries that are semantically equivalent and illustrates the difference between using the EXISTS keyword and the IN keyword. Both are examples of a valid subquery that retrieves one instance of each product name for which the product model is a long sleeve logo jersey, and the ProductModelID numbers match between the Product and ProductModel tables.
USE AdventureWorks2012;
GO
SELECT DISTINCT Name
FROM Production.Product AS p
WHERE EXISTS
(SELECT *
FROM Production.ProductModel AS pm
WHERE p.ProductModelID = pm.ProductModelID
AND pm.Name LIKE 'Long-Sleeve Logo Jersey%');
GO
-- OR
USE AdventureWorks2012;
GO
SELECT DISTINCT Name
FROM Production.Product
WHERE ProductModelID IN
(SELECT ProductModelID
FROM Production.ProductModel
WHERE Name LIKE 'Long-Sleeve Logo Jersey%');
GO
The following example uses IN in a correlated, or repeating, subquery. This is a query that depends on the outer query for its values. The query is executed repeatedly, one time for each row that may be selected by the outer query. This query retrieves one instance of the first and last name of each employee for which the bonus in the SalesPerson table is 5000.00 and for which the employee identification numbers match in the Employee and SalesPerson tables.
USE AdventureWorks2012;
GO
SELECT DISTINCT p.LastName, p.FirstName
FROM Person.Person AS p
JOIN HumanResources.Employee AS e
ON e.BusinessEntityID = p.BusinessEntityID WHERE 5000.00 IN
(SELECT Bonus
FROM Sales.SalesPerson AS sp
WHERE e.BusinessEntityID = sp.BusinessEntityID);
GO
The previous subquery in this statement cannot be evaluated independently of the outer query. It requires a value for Employee.EmployeeID, but this value changes as the SQL Server Database Engine examines different rows in Employee.
A correlated subquery can also be used in the HAVING clause of an outer query. This example finds the product models for which the maximum list price is more than twice the average for the model.
USE AdventureWorks2012;
GO
SELECT p1.ProductModelID
FROM Production.Product AS p1
GROUP BY p1.ProductModelID
HAVING MAX(p1.ListPrice) >= ALL
(SELECT AVG(p2.ListPrice)
FROM Production.Product AS p2
WHERE p1.ProductModelID = p2.ProductModelID);
GO
This example uses two correlated subqueries to find the names of employees who have sold a particular product.
USE AdventureWorks2012;
GO
SELECT DISTINCT pp.LastName, pp.FirstName
FROM Person.Person pp JOIN HumanResources.Employee e
ON e.BusinessEntityID = pp.BusinessEntityID WHERE pp.BusinessEntityID IN
(SELECT SalesPersonID
FROM Sales.SalesOrderHeader
WHERE SalesOrderID IN
(SELECT SalesOrderID
FROM Sales.SalesOrderDetail
WHERE ProductID IN
(SELECT ProductID
FROM Production.Product p
WHERE ProductNumber = 'BK-M68B-42')));
GO
F. Using GROUP BY
The following example finds the total of each sales order in the database.
USE AdventureWorks2012;
GO
SELECT SalesOrderID, SUM(LineTotal) AS SubTotal
FROM Sales.SalesOrderDetail
GROUP BY SalesOrderID
ORDER BY SalesOrderID;
GO
Because of the GROUP BY clause, only one row containing the sum of all sales is returned for each sales order.
G. Using GROUP BY with multiple groups
The following example finds the average price and the sum of year-to-date sales, grouped by product ID and special offer ID.
USE AdventureWorks2012;
GO
SELECT ProductID, SpecialOfferID, AVG(UnitPrice) AS [Average Price],
SUM(LineTotal) AS SubTotal
FROM Sales.SalesOrderDetail
GROUP BY ProductID, SpecialOfferID
ORDER BY ProductID;
GO
H. Using GROUP BY and WHERE
The following example puts the results into groups after retrieving only the rows with list prices greater than $1000.
USE AdventureWorks2012;
GO
SELECT ProductModelID, AVG(ListPrice) AS [Average List Price]
FROM Production.Product
WHERE ListPrice > $1000
GROUP BY ProductModelID
ORDER BY ProductModelID;
GO
I. Using GROUP BY with an expression
The following example groups by an expression. You can group by an expression if the expression does not include aggregate functions.
USE AdventureWorks2012;
GO
SELECT AVG(OrderQty) AS [Average Quantity],
NonDiscountSales = (OrderQty * UnitPrice)
FROM Sales.SalesOrderDetail
GROUP BY (OrderQty * UnitPrice)
ORDER BY (OrderQty * UnitPrice) DESC;
GO
J. Using GROUP BY with ORDER BY
The following example finds the average price of each type of product and orders the results by average price.
USE AdventureWorks2012;
GO
SELECT ProductID, AVG(UnitPrice) AS [Average Price]
FROM Sales.SalesOrderDetail
WHERE OrderQty > 10
GROUP BY ProductID
ORDER BY AVG(UnitPrice);
GO
K. Using the HAVING clause
The first example that follows shows a HAVING clause with an aggregate function. It groups the rows in the SalesOrderDetail table by product ID and eliminates products whose average order quantities are five or less. The second example shows a HAVING clause without aggregate functions.
USE AdventureWorks2012;
GO
SELECT ProductID
FROM Sales.SalesOrderDetail
GROUP BY ProductID
HAVING AVG(OrderQty) > 5
ORDER BY ProductID;
GO
This query uses the LIKE clause in the HAVING clause.
USE AdventureWorks2012 ;
GO
SELECT SalesOrderID, CarrierTrackingNumber
FROM Sales.SalesOrderDetail
GROUP BY SalesOrderID, CarrierTrackingNumber
HAVING CarrierTrackingNumber LIKE '4BD%'
ORDER BY SalesOrderID ;
GO
L. Using HAVING and GROUP BY
The following example shows using GROUP BY, HAVING, WHERE, and ORDER BY clauses in one SELECT statement. It produces groups and summary values but does so after eliminating the products with prices over $25 and average order quantities under 5. It also organizes the results by ProductID.
USE AdventureWorks2012;
GO
SELECT ProductID
FROM Sales.SalesOrderDetail
WHERE UnitPrice < 25.00
GROUP BY ProductID
HAVING AVG(OrderQty) > 5
ORDER BY ProductID;
GO
M. Using HAVING with SUM and AVG
The following example groups the SalesOrderDetail table by product ID and includes only those groups of products that have orders totaling more than $1000000.00 and whose average order quantities are less than 3.
USE AdventureWorks2012;
GO
SELECT ProductID, AVG(OrderQty) AS AverageQuantity, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
GROUP BY ProductID
HAVING SUM(LineTotal) > $1000000.00
AND AVG(OrderQty) < 3;
GO
To see the products that have had total sales greater than $2000000.00, use this query:
USE AdventureWorks2012;
GO
SELECT ProductID, Total = SUM(LineTotal)
FROM Sales.SalesOrderDetail
GROUP BY ProductID
HAVING SUM(LineTotal) > $2000000.00;
GO
If you want to make sure there are at least one thousand five hundred items involved in the calculations for each product, use HAVING COUNT(*) > 1500 to eliminate the products that return totals for fewer than 1500 items sold. The query looks like this:
USE AdventureWorks2012;
GO
SELECT ProductID, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
GROUP BY ProductID
HAVING COUNT(*) > 1500;
GO
N. Using the INDEX optimizer hint
The following example shows two ways to use the INDEX optimizer hint. The first example shows how to force the optimizer to use a nonclustered index to retrieve rows from a table, and the second example forces a table scan by using an index of 0.
USE AdventureWorks2012;
GO
SELECT pp.FirstName, pp.LastName, e.NationalIDNumber
FROM HumanResources.Employee AS e WITH (INDEX(AK_Employee_NationalIDNumber))
JOIN Person.Person AS pp on e.BusinessEntityID = pp.BusinessEntityID
WHERE LastName = 'Johnson';
GO
-- Force a table scan by using INDEX = 0.
USE AdventureWorks2012;
GO
SELECT pp.LastName, pp.FirstName, e.JobTitle
FROM HumanResources.Employee AS e WITH (INDEX = 0) JOIN Person.Person AS pp
ON e.BusinessEntityID = pp.BusinessEntityID
WHERE LastName = 'Johnson';
GO
M. Using OPTION and the GROUP hints
The following example shows how the OPTION (GROUP) clause is used with a GROUP BY clause.
USE AdventureWorks2012;
GO
SELECT ProductID, OrderQty, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
GROUP BY ProductID, OrderQty
ORDER BY ProductID, OrderQty
OPTION (HASH GROUP, FAST 10);
GO
O. Using the UNION query hint
The following example uses the MERGE UNION query hint.
USE AdventureWorks2012;
GO
SELECT BusinessEntityID, JobTitle, HireDate, VacationHours, SickLeaveHours
FROM HumanResources.Employee AS e1
UNION
SELECT BusinessEntityID, JobTitle, HireDate, VacationHours, SickLeaveHours
FROM HumanResources.Employee AS e2
OPTION (MERGE UNION);
GO
P. Using a simple UNION
In the following example, the result set includes the contents of the ProductModelID and Name columns of both the ProductModel and Gloves tables.
USE AdventureWorks2012;
GO
IF OBJECT_ID ('dbo.Gloves', 'U') IS NOT NULL
DROP TABLE dbo.Gloves;
GO
-- Create Gloves table.
SELECT ProductModelID, Name
INTO dbo.Gloves
FROM Production.ProductModel
WHERE ProductModelID IN (3, 4);
GO
-- Here is the simple union.
USE AdventureWorks2012;
GO
SELECT ProductModelID, Name
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves
ORDER BY Name;
GO
Q. Using SELECT INTO with UNION
In the following example, the INTO clause in the second SELECT statement specifies that the table named ProductResults holds the final result set of the union of the designated columns of the ProductModel and Gloves tables. Note that the Gloves table is created in the first SELECT statement.
USE AdventureWorks2012;
GO
IF OBJECT_ID ('dbo.ProductResults', 'U') IS NOT NULL
DROP TABLE dbo.ProductResults;
GO
IF OBJECT_ID ('dbo.Gloves', 'U') IS NOT NULL
DROP TABLE dbo.Gloves;
GO
-- Create Gloves table.
SELECT ProductModelID, Name
INTO dbo.Gloves
FROM Production.ProductModel
WHERE ProductModelID IN (3, 4);
GO
USE AdventureWorks2012;
GO
SELECT ProductModelID, Name
INTO dbo.ProductResults
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves;
GO
SELECT ProductModelID, Name
FROM dbo.ProductResults;
R. Using UNION of two SELECT statements with ORDER BY
The order of certain parameters used with the UNION clause is important. The following example shows the incorrect and correct use of UNION in two SELECT statements in which a column is to be renamed in the output.
USE AdventureWorks2012;
GO
IF OBJECT_ID ('dbo.Gloves', 'U') IS NOT NULL
DROP TABLE dbo.Gloves;
GO
-- Create Gloves table.
SELECT ProductModelID, Name
INTO dbo.Gloves
FROM Production.ProductModel
WHERE ProductModelID IN (3, 4);
GO
/* INCORRECT */
USE AdventureWorks2012;
GO
SELECT ProductModelID, Name
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
ORDER BY Name
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves;
GO
/* CORRECT */
USE AdventureWorks2012;
GO
SELECT ProductModelID, Name
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves
ORDER BY Name;
GO
S. Using UNION of three SELECT statements to show the effects of ALL and parentheses
The following examples use UNION to combine the results of three tables that all have the same 5 rows of data. The first example uses UNION ALL to show the duplicated records, and returns all 15 rows. The second example uses UNION without ALL to eliminate the duplicate rows from the combined results of the three SELECT statements, and returns 5 rows.
The third example uses ALL with the first UNION and parentheses enclose the second UNION that is not using ALL. The second UNION is processed first because it is in parentheses, and returns 5 rows because the ALL option is not used and the duplicates are removed. These 5 rows are combined with the results of the first SELECT by using the UNION ALL keywords. This does not remove the duplicates between the two sets of 5 rows. The final result has 10 rows.
USE AdventureWorks2012;
GO
IF OBJECT_ID ('dbo.EmployeeOne', 'U') IS NOT NULL
DROP TABLE dbo.EmployeeOne;
GO
IF OBJECT_ID ('dbo.EmployeeTwo', 'U') IS NOT NULL
DROP TABLE dbo.EmployeeTwo;
GO
IF OBJECT_ID ('dbo.EmployeeThree', 'U') IS NOT NULL
DROP TABLE dbo.EmployeeThree;
GO
SELECT pp.LastName, pp.FirstName, e.JobTitle
INTO dbo.EmployeeOne
FROM Person.Person AS pp JOIN HumanResources.Employee AS e
ON e.BusinessEntityID = pp.BusinessEntityID
WHERE LastName = 'Johnson';
GO
SELECT pp.LastName, pp.FirstName, e.JobTitle
INTO dbo.EmployeeTwo
FROM Person.Person AS pp JOIN HumanResources.Employee AS e
ON e.BusinessEntityID = pp.BusinessEntityID
WHERE LastName = 'Johnson';
GO
SELECT pp.LastName, pp.FirstName, e.JobTitle
INTO dbo.EmployeeThree
FROM Person.Person AS pp JOIN HumanResources.Employee AS e
ON e.BusinessEntityID = pp.BusinessEntityID
WHERE LastName = 'Johnson';
GO
-- Union ALL
SELECT LastName, FirstName, JobTitle
FROM dbo.EmployeeOne
UNION ALL
SELECT LastName, FirstName ,JobTitle
FROM dbo.EmployeeTwo
UNION ALL
SELECT LastName, FirstName,JobTitle
FROM dbo.EmployeeThree;
GO
SELECT LastName, FirstName,JobTitle
FROM dbo.EmployeeOne
UNION
SELECT LastName, FirstName, JobTitle
FROM dbo.EmployeeTwo
UNION
SELECT LastName, FirstName, JobTitle
FROM dbo.EmployeeThree;
GO
SELECT LastName, FirstName,JobTitle
FROM dbo.EmployeeOne
UNION ALL
(
SELECT LastName, FirstName, JobTitle
FROM dbo.EmployeeTwo
UNION
SELECT LastName, FirstName, JobTitle
FROM dbo.EmployeeThree
);
GO