请问怎么用js读取、存入mysql数据库？

$('.button_addTag').click(function(){
var $this = $(this);
var marketTitle = $('#sug_startup_market').val();
var temp = 1 ;
$('.button_addTag').parents('li').find('.added_tag span').each(function(i,val){
if($.trim($(val).text())==$.trim(marketTitle)){
temp = 0;
}
});
if($this.parents('li').find('.added_tag span').length >= 5 || temp ==0){
$('#myMarketEdit').siblings('div').find('.form_wrong_tips').text('最多只能选择五个行业').show();
$('#sug_startup_market').val("");
$('#sug_startup_market').parent().find('ul').hide();
return false;
}
if(marketTitle != ''){
var postData = "startupId=0&investorId=0&marketItem.title="+marketTitle;
$.ajax({
type : "POST",
url : "/common/addMarket.html",
data : postData,
success : function(response) {
response = window["eval"]("(" + response + ")");
if(response!=null){
$this.parents('li').find('.added_tag').append("<span item_id=\""+response.id+"\">"+response.title+"<strong class=\"delete\"></strong></span>");
var tagTitle = response.title;
if($('.added_tag').parents('li').find('.form_hot_tag a').length>0){
$('.added_tag').parents('li').find('.form_hot_tag a').each(function(i,val){
if($.trim($(val).text())==$.trim(tagTitle)){
$(val).addClass('added');
}
});
}
}
$('#sug_startup_market').val("");
$('#sug_startup_market').parent().find('ul').hide();
return false;
}
});
};
}); 

这是一个工程的代码，你看，好像能满足你的要求