Requete SQL

What is the appropriate orthographe for using et requet field and get the number of lines in the rsform table such as :

SELECT COUNT(`SubmissionId`)
FROM `#__rsform_submission_values`
WHERE `FORMId`=45

Dont get any answer

We can't help on third-party components, sorry. Please ask the rsforms provider for help regarding his component and what query you need to get the result you want to use from rsforms.

Can we put some "under-SELECT" in the query

such as SELECT COUNT`SubmissionId`
FROM `#__rsform_submissions`
WHERE `FORMId`=45 AND `UserId`=[user_id] AND (SELECT `SubmissionId` FROM `#__rsform_submission_values` WHERE `info_subid`=0)

SQL queries allow sub-queries, but again, we can't help on third-party components tables we don't know the structure nor content.

if you google for mysql subqueries you will find examples and tutorials and the MySQL manual page for the sub-queries syntax.

I assume you're asking about CB Query Field and its Query Field for displaying the results of custom database queries on profile? It supports any valid SQL statement so yes you can output the count of a table. Otherwise you'll need to be more specific as to WHERE you're trying to use that query as several query usages have difference behavior (e.g. query conditions, userlist filtering, userlist sorting, etc..).

Thank for your answer. Following your tutorials I get the following result.
Do you have any clue for that ?

Here is my query :
SELECT `lastname`,`cb_ville`,`cb_cp` FROM `#__comprofiler` WHERE `cb_titre`=2;

here is my presentation

Before :
<table>
<thead>
<tr>
<th scope="col" style="text-align:left; width: 70%;">Discipline</th>
<th scope="col" style="text-align:left; width: 20%;">Nature</th>
<th scope="col" style="text-align:center; width: 10%;">CP</th>
</tr>
</thead>
<tbody>

In the middle :

<tr>
<td style="text-align:left;">[column_lastname]</td>
<td style="text-align:left;">[column_cb_ville]</td>
<td style="text-align:center;">[column_cb_cp]</td>
</tr>

In the end </tbody>
</table>