how i can connect SQL database in client side by ajax or java script and fill select by this
To answer your question, even though it's already been answered in this thread, JavaScript cannot access or connect to the database. You would need server-side code for this. Make a request to the server-side script which would return a response which you can use on the client-side. See an
example (replace the ASP with the language of your choice). To fill the select element, either return the HTML and set the innerHTML to that, or return JSON or XML which can be parsed to get the data.