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 AdventureWorks database.
USE AdventureWorks;
GO
SELECT *
FROM Production.Product
ORDER BY Name ASC;
-- Alternate way.
USE AdventureWorks;
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 AdventureWorks database. Additionally, a column heading is added.
USE AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
GO
SELECT DISTINCT Title
FROM HumanResources.Employee
ORDER BY Title;
GO
D. Creating tables with SELECT INTO
The following first example creates a temporary table named #Bicycles in tempdb. To use this table, always refer to it with the exact name that is shown. This includes the number sign (#).
USE tempdb;
IF OBJECT_ID (N'#Bicycles',N'U') IS NOT NULL
DROP TABLE #Bicycles;
GO
SELECT *
INTO #Bicycles
FROM Production.Product
WHERE ProductNumber LIKE 'BK%';
GO
Here is the result set.
name
------------------------------
#Bicycles_____________________
This second example creates the permanent table NewProducts.
USE AdventureWorks;
GO
IF OBJECT_ID ('dbo.NewProducts', 'U') IS NOT NULL
DROP TABLE dbo.NewProducts;
GO
ALTER DATABASE AdventureWorks SET RECOVERY BULK_LOGGED;
GO
SELECT * INTO dbo.NewProducts
FROM Production.Product
WHERE ListPrice > $25
AND ListPrice < $100;
GO
ALTER DATABASE AdventureWorks SET RECOVERY FULL;
GO
Here is the result set.
name
------------------------------
NewProducts
(1 row(s) affected)
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 AdventureWorks;
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 = 'Long-sleeve logo jersey');
GO
-- OR
USE AdventureWorks;
GO
SELECT DISTINCT Name
FROM Production.Product
WHERE ProductModelID IN
(SELECT ProductModelID
FROM Production.ProductModel
WHERE Name = '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 AdventureWorks;
GO
SELECT DISTINCT c.LastName, c.FirstName
FROM Person.Contact AS c
JOIN HumanResources.Employee AS e
ON e.ContactID = c.ContactID WHERE 5000.00 IN
(SELECT Bonus
FROM Sales.SalesPerson AS sp
WHERE e.EmployeeID = sp.SalesPersonID);
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 AdventureWorks;
GO
SELECT p1.ProductModelID
FROM Production.Product AS p1
GROUP BY p1.ProductModelID
HAVING MAX(p1.ListPrice) >= ALL
(SELECT 2 * 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 AdventureWorks;
GO
SELECT DISTINCT c.LastName, c.FirstName
FROM Person.Contact c JOIN HumanResources.Employee e
ON e.ContactID = c.ContactID WHERE EmployeeID 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 AdventureWorks;
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 AdventureWorks
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks ;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
GO
SELECT ProductID, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
GROUP BY ProductID
HAVING COUNT(*) > 1500;
GO
N. Calculating group totals by using COMPUTE BY
The following example uses two code examples to show the use of COMPUTE BY. The first code example uses one COMPUTE BY with one aggregate function, and the second code example uses one COMPUTE BY item and two aggregate functions.
This query calculates the sum of the orders, for products with prices less than $5.00, for each type of product.
USE AdventureWorks;
GO
SELECT ProductID, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
ORDER BY ProductID, LineTotal
COMPUTE SUM(LineTotal) BY ProductID;
GO
This query retrieves the product type and order total for products with unit prices under $5.00. The COMPUTE BY clause uses two different aggregate functions.
USE AdventureWorks;
GO
SELECT ProductID, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
ORDER BY ProductID, LineTotal
COMPUTE SUM(LineTotal), MAX(LineTotal) BY ProductID;
GO
O. Calculating grand values by using COMPUTE without BY
The COMPUTE keyword can be used without BY to generate grand totals, grand counts, and so on.
The following example finds the grand total of the prices and advances for all types of products les than $2.00.
USE AdventureWorks;
GO
SELECT ProductID, OrderQty, UnitPrice, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $2.00
COMPUTE SUM(OrderQty), SUM(LineTotal);
GO
You can use COMPUTE BY and COMPUTE without BY in the same query. The following query finds the sum of order quantities and line totals by product type, and then computes the grand total of order quantities and line totals.
USE AdventureWorks;
GO
SELECT ProductID, OrderQty, UnitPrice, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
ORDER BY ProductID
COMPUTE SUM(OrderQty), SUM(LineTotal) BY ProductID
COMPUTE SUM(OrderQty), SUM(LineTotal);
GO
P. Calculating computed sums on all rows
The following example shows only three columns in the select list and gives totals based on all order quantities and all line totals at the end of the results.
USE AdventureWorks;
GO
SELECT ProductID, OrderQty, LineTotal
FROM Sales.SalesOrderDetail
COMPUTE SUM(OrderQty), SUM(LineTotal);
GO
Q. Using more than one COMPUTE clause
The following example finds the sum of the prices of all orders whose unit price is less than $5 organized by product ID and order quantity, as well as the sum of the prices of all orders less than $5 organized by product ID only. You can use different aggregate functions in the same statement by including more than one COMPUTE BY clause.
USE AdventureWorks;
GO
SELECT ProductID, OrderQty, UnitPrice, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
ORDER BY ProductID, OrderQty, LineTotal
COMPUTE SUM(LineTotal) BY ProductID, OrderQty
COMPUTE SUM(LineTotal) BY ProductID;
GO
R. Comparing GROUP BY with COMPUTE
The first example that follows uses the COMPUTE clause to calculate the sum of all orders whose product's unit price is less than $5.00, by type of product. The second example produces the same summary information by using only GROUP BY.
USE AdventureWorks;
GO
SELECT ProductID, LineTotal
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
ORDER BY ProductID
COMPUTE SUM(LineTotal) BY ProductID;
GO
This is the second query that uses GROUP BY.
USE AdventureWorks;
GO
SELECT ProductID, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
GROUP BY ProductID
ORDER BY ProductID;
GO
S. Using SELECT with GROUP BY, COMPUTE, and ORDER BY clauses
The following example returns only those orders whose unit price is less than $5, and then computes the line total sum by product and the grand total. All computed columns appear within the select list.
USE AdventureWorks;
GO
SELECT ProductID, OrderQty, SUM(LineTotal) AS Total
FROM Sales.SalesOrderDetail
WHERE UnitPrice < $5.00
GROUP BY ProductID, OrderQty
ORDER BY ProductID, OrderQty
COMPUTE SUM(SUM(LineTotal)) BY ProductID, OrderQty
COMPUTE SUM(SUM(LineTotal));
GO
T. 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 the specifically named INDEX.
USE AdventureWorks;
GO
SELECT c.FirstName, c.LastName, e.Title
FROM HumanResources.Employee AS e WITH (INDEX(IX_Employee_ManagerID))
JOIN Person.Contact AS c on e.ContactID = c.ContactID
WHERE ManagerID = 3;
GO
-- Force a table scan by using INDEX = 0.
USE AdventureWorks;
GO
SELECT c.LastName, c.FirstName, e.Title
FROM HumanResources.Employee AS e WITH (INDEX = 0) JOIN Person.Contact AS c
ON e.ContactID = c.ContactID
WHERE LastName = 'Johnson';
GO
U. Using OPTION and the GROUP hints
The following example shows how the OPTION (GROUP) clause is used with a GROUP BY clause.
USE AdventureWorks;
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
V. Using the UNION query hint
The following example uses the MERGE UNION query hint.
USE AdventureWorks;
GO
SELECT *
FROM HumanResources.Employee AS e1
UNION
SELECT *
FROM HumanResources.Employee AS e2
OPTION (MERGE UNION);
GO
W. 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 AdventureWorks;
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 AdventureWorks;
GO
SELECT ProductModelID, Name
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves
ORDER BY Name;
GO
X. 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 AdventureWorks;
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 AdventureWorks;
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 *
FROM dbo.ProductResults;
Y. 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 AdventureWorks;
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 AdventureWorks;
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 AdventureWorks;
GO
SELECT ProductModelID, Name
FROM Production.ProductModel
WHERE ProductModelID NOT IN (3, 4)
UNION
SELECT ProductModelID, Name
FROM dbo.Gloves
ORDER BY Name;
GO
Z. 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 AdventureWorks;
GO
IF OBJECT_ID ('dbo.EmployeeOne', 'U') IS NOT NULL
DROP TABLE EmployeeOne;
GO
IF OBJECT_ID ('dbo.EmployeeTwo', 'U') IS NOT NULL
DROP TABLE EmployeeTwo;
GO
IF OBJECT_ID ('dbo.EmployeeThree', 'U') IS NOT NULL
DROP TABLE EmployeeThree;
GO
SELECT c.LastName, c.FirstName, e.Title
INTO dbo.EmployeeOne
FROM Person.Contact AS c JOIN HumanResources.Employee AS e
ON e.ContactID = c.ContactID
WHERE ManagerID = 66;
GO
SELECT c.LastName, c.FirstName, e.Title
INTO dbo.EmployeeTwo
FROM Person.Contact AS c JOIN HumanResources.Employee AS e
ON e.ContactID = c.ContactID
WHERE ManagerID = 66;
GO
SELECT c.LastName, c.FirstName, e.Title
INTO dbo.EmployeeThree
FROM Person.Contact AS c JOIN HumanResources.Employee AS e
ON e.ContactID = c.ContactID
WHERE ManagerID = 66;
GO
-- Union ALL
SELECT LastName, FirstName
FROM dbo.EmployeeOne
UNION ALL
SELECT LastName, FirstName
FROM dbo.EmployeeTwo
UNION ALL
SELECT LastName, FirstName
FROM dbo.EmployeeThree;
GO
SELECT LastName, FirstName
FROM dbo.EmployeeOne
UNION
SELECT LastName, FirstName
FROM dbo.EmployeeTwo
UNION
SELECT LastName, FirstName
FROM dbo.EmployeeThree;
GO
SELECT LastName, FirstName
FROM dbo.EmployeeOne
UNION ALL
(
SELECT LastName, FirstName
FROM dbo.EmployeeTwo
UNION
SELECT LastName, FirstName
FROM dbo.EmployeeThree
);
GO
See Also