SQL SELECT UNIQUE

The SELECT UNIQUE construct is an Oracle-only SQL statement. It is equivalent to SELECT DISTINCT.

Syntax

The syntax for SELECT UNIQUE is as follows:

Example

We use the following table for our example.

Table Store_Information

To select all distinct stores in Table Store_Information in Oracle, we key in,

Result:

Exercises

For these exercises, assume we have a table called Region_Sales with the following data:

Table Region_Sales

1. (True or False) The following two statements are equivalent in MySQL:
SELECT UNIQUE Region FROM Region_Sales;
SELECT DISTINCT Region FROM Region_Sales;

2. Which of the following statements are valid in Oracle?
a) SELECT DISTINCT Year FROM Region_Sales;
b) SELECT UNIQUE * FROM Region_Sales;
c) SELECT * FROM Region_Sales;
d) SELECT UNIQUE Year FROM Region_Sales;

3. What is the output for the following statement?
SELECT UNIQUE Region FROM Region_Sales WHERE Orders < 1000;