title: How to create a view with multiple select queries that returns multiple rows in oracle?
body: <p>I have a table like this in Oracle
  table name: links</p>
  <pre><code>|url             |category|
  |----------------|--------|
  |www.google.com  |search  |
  |----------------|--------|
  |www.facebook.com|Social  |
  |----------------|--------|
  |www.twiter.com  |Social  |
  |----------------|--------|
  
  </code></pre>
  <p>and I have to create a view like this</p>
  <pre><code>|search          |Social          |
  |----------------|----------------|
  |www.google.com  |www.facebook.com|
  |----------------|----------------|
  |                |www.twiter.com  |
  |----------------|----------------|
  </code></pre>
  <p>I have tried the following sql</p>
  <pre><code>CREATE OR REPLACE VIEW v1 AS(
      SELECT(
          (SELECT * FROM Links WHERE category='Search'),
          (SELECT * FROM Links WHERE category='Social')
      ) FROM Dual);
  </code></pre>
  <p>but it returns the following error:</p>
  <blockquote>
  <p>missing right parentheses</p>
  </blockquote>
  <p>when I try to run the following section of the sql</p>
  <pre><code>SELECT(
          (SELECT * FROM Links WHERE category='Search'),
          (SELECT * FROM Links WHERE category='Social')
      ) FROM Dual;
  </code></pre>
  <p>It returns the following error:</p>
  <blockquote>
  <p>Signle subquery returns multiple rows.</p>
  </blockquote>
  <p>Please somebody help me. And also let me know if it is possible at all.
  Thanks</p>