MySQL JSON_EXTRACT path expression error : <p>The syntax looks right to me, any help would be appreciated!</p>

<pre><code>mysql&gt; select fieldnames from tablename limit 5;
+--------------------------------------------------------+
| fieldnames                                             |
+--------------------------------------------------------+
| {"example-field-1": "val2"}                            |
| {"example-field-2": "val1"}                            |
| {"example-field-1": "val1", "example-field-3": "val1"} |
| {"example-field-2": "val1"}                            |
| {"example-field-2": "val2"}                            |
+--------------------------------------------------------+
mysql&gt; select JSON_EXTRACT(fieldnames, '$.example-field-1') from tablename;
ERROR 3143 (42000): Invalid JSON path expression. The error is around character position 17 in '$.example-field-1'.
</code></pre>

<p>MySQL 5.7.10</p>
