我想创建一个带按钮的weabpp。通过点击按钮，我想在JavaScript IndexedDB中存储一个字符串。我需要一个函数。在onupgradneeded事件中编写它，对我没有帮助。我的实际代码是：

<script>    
function createDB(dbName, dbVersion) {
    const request = indexedDB.open(dbName, dbVersion)

    // upgrade needed
    request.onupgradeneeded = e => {
        const db = e.target.result
        db.createObjectStore("wdesk")
        console.log("Upgrade is called")
    }

    // successful
    request.onsuccess = e => {
        console.log("Success")
    }

    // error
    request.onerror = e => {
        console.log("Error")
    }
}
<script>
<button onclick="">Store HelloWorld</button>