title: get a common value from multiple tables using SQL
body: <p>Below is my values in each table</p>
  
  <p>Reading - Table name</p>
  
  <p>student_id - student ID</p>
  
  <pre><code>1
  4
  5
  7
  6
  9
  11
  </code></pre>
  
  <p>speaking -  table</p>
  
  <pre><code>9
  10
  12
  13
  14
  15
  </code></pre>
  
  <p>writing - table</p>
  
  <pre><code>1
  2
  3
  4
  5
  6
  7
  9
  </code></pre>
  
  <p>Listening - table</p>
  
  <pre><code>1
  2
  3
  4
  5
  6
  7
  8
  9
  </code></pre>
  
  <p>My query will return the student_id's which is common in 4 tables . for example
  my query will return for this example is</p>
  
  <p>only 9 'id is common for all tables so the query will return the count as 1.
  I tried with inner join and some distinct way of queries but in result I'm getting wrong answer.Please anyone help me to get out of this issue.Thanks in advance.</p>