# SQL Aliases

### SQL Aliases

SQL aliases are used to give a table, or a column in a table, a temporary name.

Aliases are often used to make column names more readable.

An alias only exists for the duration of the query.

#### Alias Column Syntax

```sql
SELECT column_name AS alias_name
FROM table_name;
```

#### Alias Table Syntax

```sql
SELECT column_name(s)
FROM table_name AS alias_name;
```

### Demo Database

In this tutorial we will use the well-known Northwind sample database.

Below is a selection from the "Customers" table:<br>

![](https://826093633-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LS8lPNzCGPR5-DLbGXv%2F-LSTPzUYVoZZyM5Svbsy%2F-LSTQqMm4pZxzDga0TEI%2Fimage.png?alt=media\&token=07d8b31d-8171-40c5-9df8-2a6728751446)

And a selection from the "Orders" table:

![](https://826093633-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LS8lPNzCGPR5-DLbGXv%2F-LSTPzUYVoZZyM5Svbsy%2F-LSTQxjdt-HAfmMDxZcY%2Fimage.png?alt=media\&token=9bf37bb2-9181-4f5c-8c65-68ff1741f070)

Alias for Columns Examples

The following SQL statement creates two aliases, one for the CustomerID column and one for the CustomerName column:

```sql
SELECT CustomerID AS ID, CustomerName AS Customer
FROM Customers;
```

&#x20;The following SQL statement creates two aliases, one for the CustomerName column and one for the ContactName column. **Note:** It requires double quotation marks or square brackets if the alias name contains spaces:

```sql
SELECT CustomerName AS Customer
ContactName AS [Contact Person]
FROM Customers;
```

The following SQL statement creates an alias named "Address" that combine four columns (Address, PostalCode, City and Country):

```sql
SELECT CustomerName, Address + ', ' + PostalCode + ' ' + City + ', ' + Country AS Address
FROM Customers;
```

Alias for Tables Example

The following SQL statement selects all the orders from the customer with CustomerID=4 (Around the Horn). We use the "Customers" and "Orders" tables, and give them the table aliases of "c" and "o" respectively (Here we use aliases to make the SQL shorter):

```sql
SELECT o.OrderID, o.OrderDate, c.CustomerName
FROM Customers AS c, Orders AS o
WHERE c.CustomerName="Around the Horn" AND c.Cu.CustomerID;

```

> Aliases can be useful when:
>
> * There are more than one table involved in a query
> * Functions are used in the query
> * Column names are big or not very readable
> * Two or more columns are combined together

\
\ <br>