javascript函数中的php

您好，我正在编写一个PHP应用程序，当我需要检查来自数据库的表单输入时，我感到震惊

<form id="form1" name="form1" method="post">
<input type="text" id="acname" name="acname"/>
<button name="save" type="submit" onclick="return checkform()">Save</button>
</form>

Javascript函数

<SCRIPT LANGUAGE="JavaScript">
function checkform()
{
   if ($.trim($("#acname").val()).length == 0){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 

//Here I need to check the name is already in the database or not, so I require the PHP Code to interact with database, how Can I achieve this??
}

function checkform()
{
   if ($.trim($("#acname").val()) == ''){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 
       $.post(<url>,{name:$("#acname").val()},function(){alert('data saved');});

}

---

使用Javascript执行页面内AJAX请求，提交名称，然后使用PHP检查名称，返回一个JSON对象，说明名称是否已被使用

我看到您使用jQuery，所以请检查 一个简单的例子是

$.ajax( "check.php?name=" + $("#acname").val() )
.done(function(data) { console.log("Return message is ", data); })
.fail(function() { console.log("Something went wrong"); });

---

请注意，提交表单时，请再次检查服务器端的可用性。永远不要相信来自前端的东西

使用Javascript执行页面内AJAX请求，提交名称，然后使用PHP检查名称，返回一个JSON对象，说明名称是否已被使用

我看到您使用jQuery，所以请检查 一个简单的例子是

$.ajax( "check.php?name=" + $("#acname").val() )
.done(function(data) { console.log("Return message is ", data); })
.fail(function() { console.log("Something went wrong"); });

请注意，提交表单时，请再次检查服务器端的可用性。永远不要相信来自前端的东西

HTML

PHP

HTML

PHP

---

如何使用Javascript函数

<SCRIPT LANGUAGE="JavaScript">
function checkform()
{
   if ($.trim($("#acname").val()).length == 0){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 

//Here I need to check the name is already in the database or not, so I require the PHP Code to interact with database, how Can I achieve this??
}

function checkform()
{
   if ($.trim($("#acname").val()) == ''){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 
       $.post(<url>,{name:$("#acname").val()},function(){alert('data saved');});

}

---

如何使用Javascript函数

<SCRIPT LANGUAGE="JavaScript">
function checkform()
{
   if ($.trim($("#acname").val()).length == 0){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 

//Here I need to check the name is already in the database or not, so I require the PHP Code to interact with database, how Can I achieve this??
}

function checkform()
{
   if ($.trim($("#acname").val()) == ''){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 
       $.post(<url>,{name:$("#acname").val()},function(){alert('data saved');});

}

---

使用XML RPC调用与数据库对话。 为了清楚起见，我在下面的示例中使用了同步调用，如rpc.open的false参数所示

function checkform()
{
   var name = $.trim($("#acname").val());
   if (name.length == 0){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 

    // Ask the database. The 'http://host/check_name_in_db.php' must be a PHP script
    // that can handle receiving an HTTP POST with a parameter named 'name'. It then
    // has to determine if the name passed in exists or not and return an answer.
    // The answer can be in any format you'd like, many people use XML or JSON for this.
    // For this example, I just assume that your PHP script will return (echo, print,
    // printf()) the strings 'yes' or 'no' as a response to whether or not the name was
    // found in the database.
    var params='name='+name;
    var rpc = new XMLHttpRequest();
    rpc.open('POST', 'http://host/check_name_in_db.php', false);
    rpc.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    rpc.send(params);

    // Wait until the RPC request is complete.
    // This is somewhat dangerous as an RPC call _can_ be aborted for example.
    // That could cause your javascript to hang here.
    while (rpc.readyState != 4) {};
    var reply = rpc.responseText;

    // Your PHP script wrote 'yes' back to us, which would mean that the name was
    // found in the database.
    if (reply == 'yes')
    {
        return true;
    }
    else
    {
        return false;
    }
}

---

使用XML RPC调用与数据库对话。 为了清楚起见，我在下面的示例中使用了同步调用，如rpc.open的false参数所示

function checkform()
{
   var name = $.trim($("#acname").val());
   if (name.length == 0){
        alert("Please Enter Name");
        $("#acname").focus();
        return false;
    } 

    // Ask the database. The 'http://host/check_name_in_db.php' must be a PHP script
    // that can handle receiving an HTTP POST with a parameter named 'name'. It then
    // has to determine if the name passed in exists or not and return an answer.
    // The answer can be in any format you'd like, many people use XML or JSON for this.
    // For this example, I just assume that your PHP script will return (echo, print,
    // printf()) the strings 'yes' or 'no' as a response to whether or not the name was
    // found in the database.
    var params='name='+name;
    var rpc = new XMLHttpRequest();
    rpc.open('POST', 'http://host/check_name_in_db.php', false);
    rpc.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    rpc.send(params);

    // Wait until the RPC request is complete.
    // This is somewhat dangerous as an RPC call _can_ be aborted for example.
    // That could cause your javascript to hang here.
    while (rpc.readyState != 4) {};
    var reply = rpc.responseText;

    // Your PHP script wrote 'yes' back to us, which would mean that the name was
    // found in the database.
    if (reply == 'yes')
    {
        return true;
    }
    else
    {
        return false;
    }
}

---

您应该执行一个AJAX请求来检查名称。在该上下文中编写PHP代码是不可能的。您需要发出AJAX请求。但是，在这种情况下，直接这样做是不起作用的，因为事件处理程序是同步的，而AJAX不是同步的。您对数据库的结构或类型只字未提，因此很难提供任何帮助。您应该执行AJAX请求以检查名称。在该上下文中编写PHP代码是不可能的。您需要发出AJAX请求。但是，在这种情况下，直接这样做是不起作用的，因为事件处理程序是同步的，而AJAX不是同步的。您对数据库的结构或类型只字未提，因此很难提供任何帮助。请打开一个新问题，并给出确切的错误消息，以及您已经尝试过的内容，我将尝试查看它！请打开一个带有确切错误消息的新问题，以及您已经尝试过的内容，我将尝试查看它！