title: use sqlite check to validate whether date with proper format is entered in the column
body: <p>I have created a table as below:</p>
  
  <pre><code>CREATE TABLE case_status(data_entry_timestamp DATETIME DEFAULT (datetime('now','localtime')) NOT NULL,
                           case_number TEXT PRIMARY KEY NOT NULL, 
                           case_name TEXT DEFAULT MISSING, 
                           death_reportdate DATE CONSTRAINT death_reportdate_chk CHECK (death_reportdate==strftime('%Y-%m-%d',death_reportdate)),
                           );
  </code></pre>
  
  <p>The column <code>death_reportdate</code> need to have a date with pre-defined format (e.g. 2000-12-31). I created the table, inserted some rows of data, and then try to modified data in <code>death_reportdate</code>, the check rule seems to be bypassed when I enter some random string to it.</p>
  
  <p>What have I done wrong?</p>