title: SQL - Column in field list is ambiguous
body: <p>I have two tables BOOKINGS and WORKER. Basically there is table for a worker and a table to keep track of what the worker has to do in a time frame aka booking. I’m trying to check if there is an available worker for a job, so I query the booking to check if requested time has available workers between the start end date. However, I get stuck on the next part. Which is returning the list of workers that do have that time available. I read that I could join the table passed on a shared column, so I tried doing an inner join with the WORKER_NAME column, but when I try to do this I get a ambiguous error. This leads me to believe I misunderstood the concept. Does anyone understand what I;m trying to do and knows how to do it, or knows why I have the error below. Thanks guys !!!!</p>
  
  <pre><code>CREATE TABLE WORKER (
              ID INT NOT NULL AUTO_INCREMENT,
              WORKER_NAME  varchar(80) NOT NULL,
              WORKER_CODE  INT, 
              WORKER_WAGE  INT, 
              PRIMARY KEY (ID)
  )
  
  CREATE TABLE BOOKING (
              ID INT NOT NULL AUTO_INCREMENT,
              WORKER_NAME  varchar(80) NOT NULL,
              START DATE NOT NULL,
              END DATE NOT NULL, 
              PRIMARY KEY (ID)
  )
  </code></pre>
  
  <p>query</p>
  
  <pre><code>SELECT *
  FROM WORKERS
  INNER JOIN BOOKING
  ON WORKER_NAME = WORKER_NAME
  WHERE (START NOT BETWEEN '2010-10-01' AND '2010-10-10')
  ORDER BY ID
  </code></pre>
  
  <p>#1052 - Column 'WORKER_NAME' in on clause is ambiguous </p>