Getting results from a Promise function within Promise chain

What I am trying to do here is painfully easy in other languages but I'm trying to understand Promises as I learn more about Node.js. I decided I'd do a quick loop over some data leftover from an old plugin in a WordPress database to create a report. This implementation isn't necessary as I could JOIN some of the data so please don't think less of me.

function suggestionGetComments(row) {
    let commentsDiv = ''
    return new Promise((resolve, reject) => {
        sqlGet(`SELECT * FROM wp_comments WHERE comment_post_id = ${row.ID};`)
            .then((result) => {
                result.forEach(comment => {
                    commentsDiv += 'comments stuff'
                })
            })
            .then(() => {
                if (commentsDiv != '')
                    commentsDiv = '\t<ul class="suggestionComments">\n' + commentsDiv + '\t</ul>\n'
                resolve(commentsDiv)
            })
            .catch((err) => {
                console.error(err.message)
                reject('*** Error with wp_comments ***')
            })
    })
}

function suggestionGetMeta(id) {
    let userName, userEmail
    return new Promise((resolve, reject) => {
        sqlGet(`SELECT * FROM wp_postmeta WHERE post_id = ${id};`)
            .then((result) => {
                result.forEach(row => {
                    if (row.meta_key === '_avia_feedback_author')
                        userName = row.meta_value
                    else if (row.meta_key === '_avia_feedback_author_mail')
                        userEmail = row.meta_value
                })
            })
            .then(() => {
                if (userName && userEmail)
                    resolve(`${userName} (${userEmail})`)
                else
                    resolve('*** MISSING DATA ***')
            })
            .catch((err) => {
                console.error(err.message)
                reject('*** Error with wp_postmeta ***')
            })
    })
}

function suggestionDisplay(row) {
    let suggestionHTML = '<arcticle>\n'
    return new Promise((resolve, reject) => {
        const suggestionDate = new Date(Date.parse(row.post_date))
        suggestionHTML += `\t<h2>${row.post_title}</h2>\n`
        suggestionGetMeta(row.ID)
            .then((result) => {
                suggestionHTML += `\t<div class="suggestionBy">Suggested by ${result} on ${suggestionDate.toLocaleDateString()} ${suggestionDate.toLocaleTimeString()}</div>\n`
                suggestionHTML += `\t<div class="suggestionContent">${row.post_content}</div>\n`
            })
            .then(suggestionGetComments(row))
            .then((result) => {
                suggestionHTML += result
                suggestionHTML += '</article>\n'
                console.log(suggestionHTML)
                resolve('Suggestion Displayed')
            })
            .catch((err) => {
                console.error(err.message)
                reject(new Error('Failed to get Meta'))
            })
    })
}

function sqlGet(sqlText) {
    return new Promise(function(resolve, reject) {
        con.query(sqlText, function(err, rows, fields) {
            if (err) {
                return reject(err)
            }
            return resolve(rows)
        })
    })
}

The primary function suggestionDisplay works except for the call to suggestionGetComments which adds "undefined" to the string as you can see in this edited example of the output:

<arcticle>
        <h2>Some Suggestion</h2>
        <div class="suggestionBy">Suggested by someonene (some email) on 11/5/2012 3:05:50 AM</div>
        <div class="suggestionContent">The reason for the suggestion</div>
undefined</article>

Bottom line I have a Promise function suggestionDisplay which needs to call 2 other Promise functions suggestionGetMeta and suggestionGetComments both of which return values I need to process. The first works great. The second function works but I can't seem to figure out how to work with its results.