> column in the <tt>People</tt> table must be
<tt>UNIQUE</tt>. We also indicate that the combination of the two numbers
in each row of the <tt>Follows</tt> table must be unique. These constraints
keep us from making mistakes such as adding the same relationship more than
once.<br />
<br />
We can take advantage of these constraints in the following code:
</font><pre><font size="4" color="blue">
cur.execute("'INSERT OR IGNORE INTO People (name, retrieved) 
    VALUES ( ?, 0)"', ( friend, ) )
</font></pre><fo