高人帮我看看这段代码什么意思

[sunchaohehe]

String pmid="";


formParams = "mid=" + toURL(getParam( request, "mid")) + "&";

pmid = getParam( request, "mid");
if ( ! isNumber (pmid)) {
pmid = "";
}

if (pmid != null && ! pmid.equals("")) {

hasParam = true;
sWhere += "m.message_parent_id=" + pmid;
}

if (hasParam) { sWhere = " WHERE (" + sWhere + ")"; }
// Build ORDER statement
sOrder = " order by m.date_entered Desc";

// Build full SQL statement

sSQL = "select m.author as m_author, " +
"m.date_entered as m_date_entered, " +
"m.message as m_message, " +
"m.message_parent_id as m_message_parent_id, " +
"m.topic as m_topic " +
" from messages m ";

sSQL = sSQL + sWhere + sOrder;


帮我详细一点解释一下这段代码的意思，谢啦

[emon123]

就是sql拼接啊，sWhere 是where条件，sOrder是排序条件。

[sustbeckham]

构建sql语句 拼接参数

[覆水难收]

一般是多条件模糊查询用的。SQL 拼串....

[鱼大洋要学习]

[Quote=引用 2 楼 sustbeckham 的回复:]
构建sql语句 拼接参数
[/Quote]
前面是判断参数是否有值，有值就组建sql where条件
最后是将所以条件组成sql条件字符串

[hongyahe]

根据前台是否输入相关条件拼SQL串

[youlaiyouwang]

sql 拼接。

[jiangtan273405]

拼接SQL数据库语句

[码农_1987]

传入条件 接where 排序