title: Get ORA 01722 invalid number when try to copy data from one table to another
body: <p>I have to admin there is slight difference between the columns from both tables. But I thought that was minor.</p>
  <p>The table Source has three attributes</p>
  <pre><code>Amount     NUMBER(10,2)
  SHORTNAME  VARCHAR2(3)
  NAME       VARCHAR2(40)
  </code></pre>
  <p>The table Target has the same set of attributes but slightly different constraints on their type</p>
  <pre><code>Amount     NUMBER
  SHORTNAME  VARCHAR2(255)
  NAME       VARCHAR2(255)
  </code></pre>
  <p>I thought table <code>Target</code> should have more tolerance on its capacity, but when I run the query</p>
  <pre><code>insert into DB_B.Target select * from DB_A.Source ;
  </code></pre>
  <p>Unfortunately I get the popular 01722 error:</p>
  <blockquote>
  <p>SQL Error: ORA-01722: invalid number -- 01722. 00000 -  &quot;invalid number&quot;</p>
  </blockquote>
  <p>So when we say when copying data from two tables with the same schema, are we talking about 100% IDENTICAL even on the TYPE CONSTRAINT?</p>
  <p>Please help.</p>
  <h1>Update</h1>
  <p>Before thunder storm hit the office, I have to mention that the column order on both tables are different. Thanks to @a_horse_with_no_name help me think out this issue and give the perfect answer.</p>