SELECT Examples (Transact-SQL)
This topic provides examples of using the SELECT statement.
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
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
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)
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
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.
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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;
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
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
