如何设置从数据库中按值选择的选择选项？

Question

我创建了包含 3 个选择选项的注册页面和编辑页面。在注册用户时，我将数据存储在包含选择选项值的数据库中，当用户单击编辑页面时，我可以使用从数据库中获取的数据填充文本字段，但我无法选择选择选项我从数据库中得到的值是我用来执行此操作的代码：

company 变量存储来自数据库的选项值数据

<select name="select-choice-a" id="select-choice-a" data-native-menu="false" data-theme="a">
     <option>Select Company</option>
        <option value="standard">facebook</option>
        <option value="rush">Linked In</option>
        <option value="express">Skype</option>
        <option value="overnight">Twitter</option>
    </select>

JavaScript

function fetchdetails(){
db.transaction(function(tx){
    tx.executeSql(select_details,[ids,nam1],function(tx,results){
        for(var i=0;i<results.rows.length;i++){
        first_name=results.rows.item(i).frist_name;
        last_name=results.rows.item(i).last_name;
        company=results.rows.item(i).company;
        title=results.rows.item(i).title;
        industry=results.rows.item(i).industry;
        owner=results.rows.item(i).owner;
        email=results.rows.item(i).email;
        landline=results.rows.item(i).landline;
        mobile_no=results.rows.item(i).mobile;
        fax_no=results.rows.item(i).fax_no;
        website=results.rows.item(i).website;
        street=results.rows.item(i).street_name;
        city=results.rows.item(i).city;
        region=results.rows.item(i).region;
        pincode=results.rows.item(i).pincode;
        country=results.rows.item(i).country;
        linkedin=results.rows.item(i).linkedin_link;
        twitter=results.rows.item(i).twitter_link;
        facebook=results.rows.item(i).facebook_link;
        skype=results.rows.item(i).skype_link;
        additionalinfo=results.rows.item(i).additional_info;

        }
    });
});
}

var index='';
var x=document.getElementById('select-choice-a');
alert(x.options.length);
for(var i=0;i<x.options.length;i++){
    if(x.options[i].value===company)
        {
        alert("I am in select option"); 
        index=i;
        alert("index of select-choice-a"+index);
        break;
        }
}
x.options[index].selected=true;

Answer 1

替换你的代码

var index='';
var x=document.getElementById('select-choice-a');
alert(x.options.length);
for(var i=0;i<x.options.length;i++){
    if(x.options[i].value===company)
        {
        alert("I am in select option"); 
        index=i;
        alert("index of select-choice-a"+Index);
        break;
        }
}
x.options[index].selected=true;

与

<script type="text/javascript">
var company='';
fetchdetails();
var x=document.getElementById('select-choice-a');
var index=0;
for(var i=0;i<x.options.length;i++){
    if(x.options[i].value===company)
        {
        alert("I am in select option"); 
        index=i;
        alert("index of select-choice-a"+index);
        break;
        }
}
x.options[index].selected=true;
</script>