Aliasing allows the temporary substitution of a short and easy-to-remember string in place of a table or column name in SQL Data Warehouse or SQL Data Warehouse Parallel Data Warehouse DWsql] queries. Table aliases are often used in JOIN queries because the JOIN syntax requires fully qualified object names when referencing columns.
Aliases must be single words conforming to object naming rules. For more information, see “Object Naming Rules” in the [Parallel Data Warehouse product documentation](https://www.microsoft.com/en-us/download/details.aspx?id=51610) Aliases cannot contain blank spaces and cannot be enclosed in either single or double quotes.
object_source [ AS ] alias object_source
The name of the source table or column.
AS
An optional alias preposition. When working with range variable aliasing, the AS keyword is prohibited.
alias
The desired temporary reference name for the table or column. Any valid object name can be used. For more information, see “Object Naming Rules” in the [Parallel Data Warehouse product documentation](https://www.microsoft.com/en-us/download/details.aspx?id=51610)
The following example shows a query with multiple joins. Both table and column aliasing are demonstrated in this example.
Column Aliasing: Both columns and expressions involving columns in the select list are aliased in this example. SalesTerritoryRegion AS SalesTR demonstrates a simple column alias. Sum(SalesAmountQuota) AS TotalSales demonstrates
Table Aliasing: dbo.DimSalesTerritory AS st shows creation of the st alias for the dbo.DimSalesTerritory table.
-- Uses AdventureWorks
SELECT LastName, SUM(SalesAmountQuota) AS TotalSales, SalesTerritoryRegion AS SalesTR,
RANK() OVER (PARTITION BY SalesTerritoryRegion ORDER BY SUM(SalesAmountQuota) DESC ) AS RankResult
FROM dbo.DimEmployee AS e
INNER JOIN dbo.FactSalesQuota AS sq ON e.EmployeeKey = sq.EmployeeKey
INNER JOIN dbo.DimSalesTerritory AS st ON e.SalesTerritoryKey = st.SalesTerritoryKey
WHERE SalesPersonFlag = 1 AND SalesTerritoryRegion != N'NA'
GROUP BY LastName, SalesTerritoryRegion;
The AS keyword can be excluded, as shown below, but is often included for readability.
-- Uses AdventureWorks
SELECT LastName, SUM(SalesAmountQuota) TotalSales, SalesTerritoryRegion SalesTR,
RANK() OVER (PARTITION BY SalesTerritoryRegion ORDER BY SUM(SalesAmountQuota) DESC ) RankResult
FROM dbo.DimEmployee e
INNER JOIN dbo.FactSalesQuota sq ON e.EmployeeKey = sq.EmployeeKey
INNER JOIN dbo.DimSalesTerritory st ON e.SalesTerritoryKey = st.SalesTerritoryKey
WHERE SalesPersonFlag = 1 AND SalesTerritoryRegion != N'NA'
GROUP BY LastName, SalesTerritoryRegion; SELECT (Transact-SQL)
INSERT (Transact-SQL)
UPDATE (Transact-SQL)