PHP操作XML做数据库的类

<?php

* example 读取数据：
*
* xml = new xml(“dbase.xml”,’table’);
*
* data=xml->xml_fetch_array();
*
* echo “<pre style=”font-size:12px;”>”;
*
* print_r(data);
*

class xml
{
var dbase; //数据库,要读取的XML文件
var dbname; //数据库名称,顶层元素,与数据库文件名称一致
var dbtable; //数据表,要取得的节点
var parser; //剖析器
var vals; //属性
var index; //索引
var dbtable_array;//节点数组
var array; //下级节点的数组
var result; //返回的结果
var querys;

function xml(dbase,dbtable)
{
this->dbase=dbase;
this->dbname=substr(dbase,strrpos(dbase,”/”)+1,-4);
this->dbtable=dbtable;
data=this->ReadXml(this->dbase);
if(!data){
die(“无法读取 this->dbname.xml”);
}
this->parser = xml_parser_create();
xml_parser_set_option(this->parser,XML_OPTION_CASE_FOLDING,0);
xml_parser_set_option(this->parser,XML_OPTION_SKIP_WHITE,1);
xml_parse_into_struct(this->parser,data,this->vals,this->index);
xml_parser_free(this->parser);
//遍历索引，筛选出要取值的节点 节点名:dbtable
foreach (this->index as key=>val) {
if (key == this->dbtable) {
//取得节点数组
this->dbtable_array = val;
} else {
continue;
}
}
for (i=0; i < count(this->dbtable_array); i+=2) {
offset = this->dbtable_array[i] + 1;
len = this->dbtable_array[i + 1] – offset;
//array_slice() 返回根据 offset 和 length 参数所指定的 array 数组中的一段序列。
//所取节点下级数组
value=array_slice(this->vals,offset,len);
//取得有效数组，合并为结果数组
this->array[]=this->parseEFF(value);
}
return true;
}
//将XML文件读入并返回字符串
function ReadXml(file)
{
return file_get_contents(file);
}
//取得有效数组
function parseEFF(effective) {
for (i=0; i < count(effective); i++){
effect[effective[i]["tag"]] = effective[i]["value"];
}
return effect;
}
//xml_query(方法,条件,多条件时逻辑运算符and or or,插入或更新的数组)
function xml_query(method,condition,if=’and’,array=array())
{
if((method==’select’)||(method==’count’)){
return this->xml_select(method,condition,if);
} elseif(method==’insert’) {
return this->xml_insert(condition,if,array);
} elseif(method==’update’) {
return this->xml_update(condition,if,array);
}
}
//取得xml数组
function xml_fetch_array(condition,if)
{
//this->querys++;
row = this->array; //初始化数据数组
if(condition) {
//是否有条件,如有条件则生成符合条件的数组
//生成条件数组,条件格式 field,operator,match
condition=explode(“,”,condition);//条件数组
cs=count(condition)/3; //条件数
for(i=0;i<cs;i++){
conditions[]=array(“field”=>condition[i*3],”operator”=>condition[i*3+1],”match”=>condition[i*3+2]);
}
//echo count(row);
for(r=0;r<count(row);r++){
for(c=0;c<cs;c++){
//i++;
condition=conditions[c]; //当前条件
field=condition[\'field\']; //字段
operator=condition["operator"];//运算符
match=condition[\'match\']; //匹配
if((operator==’=\')&&(row[r][field]==match)){
true++;//若条件符合,符合数加1
} elseif((operator==’!=’)&&(row[r][field]!=match)){
true++;//若条件符合,符合数加1
} elseif((operator==’<’)&&(row[r][field]<match)){
true++;//若条件符合,符合数加1
} elseif((operator==’<=’)&&(row[r][field]<=match)){
true++;//若条件符合,符合数加1
} elseif((operator==’>’)&&(row[r][field]>match)){
true++;//若条件符合,符合数加1
} elseif((operator==’>’)&&(row[r][field]>=match)){
true++;//若条件符合,符合数加1
}
}
//根据条件取值
if(if==’and’){
//如果多条件为and,当符合数等于条件数时,生成数组
if(true==cs){
result[]=row[r];
}
} else {
//如果多条件为or,当有符合纪录时,生成数组
if(true!=0){
result[]=row[r];
}
}
//echo true;
//echo “<pre style=”font-size:12px;text-align:left”>”;
//print_r(true);
true=0;//符合条件数归零,进入下一轮循环
}
} else {
result=this->array;
}
//echo “<pre style=”font-size:12px;text-align:left”>”;
//print_r(this->result);
return result;
}
//筛选或统计
function xml_select(method,condition,if)
{
result=this->xml_fetch_array(condition,if);
if(method==’select’){
return result;
} else {
return count(result);
}

}
//插入数据
function xml_insert(condition,if,array)
{
data=this->xml_fetch_array(condition,if);//总数据数组
data[]=array; //插入后的总数据数组
this->array=data; //更新总数组
this->WriteXml(data);
}

//得到更新的XML并改写
function xml_update(condition,if,array)
{
datas=this->array; //总数据数组
subtract=this->xml_fetch_array(condition,if);//要更新的数组
//echo “<pre style=”font-size:12px;text-align:left”>”;
//print_r(data);
//print_r(datas);
//echo “每条记录中有”.count(datas[0]).”个值<br>”;
for(i=0;i<count(datas);i++){
data=datas[i];
//echo “原始记录中的第”.i.”条<br>”;
foreach(data as k=>v){
//echo “-第”.i.”条的”.k.”值为”.v.”<br>”;
//echo “–要查找的数组”.k.”值为”.subtract[0][k].”<br>”;
if(v==subtract[0][k]){
is++;
}
}
if(is==count(data)){
//echo “—-与第”.i.”条符合<br>”;
datas[i]=array;
//array_splice(datas,i,i+1);
}
//echo “原始记录中的第”.i.”条与要查找的有”.is.”匹配<br>”;
//echo “原始记录中的第”.i.”条结束<br>”;
is=0;
}
//array_splice(datas,2,2+1,array);
//echo “<pre style=”font-size:12px;text-align:left”>”;
//print_r(datas);
this->array=datas;
this->WriteXml(datas);

}
//写入XML文件(全部写入)
function WriteXml(array)
{
if(!is_writeable(this->dbase)){
die(“无法写入”.this->dbname.”.xml”);
}
xml.=”<?xml version=”1.0″ encoding=”utf-8″?>rn”;
xml.=”<this->dbname>rn”;
for(i=0;i<count(array);i++){
xml.=”<this->dbtable>rn”;
foreach(array[i] as k=>s){
xml.=”<k>s</k>rn”;
}
xml.=”</this->dbtable>rn”;
}
xml.=”</this->dbname>”;
fp=@fopen(this->dbase,”w”);
flock(fp, LOCK_EX);
rewind(fp);
fputs(fp,xml);
fclose(fp);
}
//逐行写入xml(我试着写入10000行,感觉没一次写入快，所以没用这种写入方式)
function WriteLine(array)
{
if(!is_writeable(this->dbase)){
die(“无法写入”.this->dbname.”.xml”);
}
fp=@fopen(this->dbase,”w”);
rewind(fp);
flock(fp, LOCK_EX);
fputs(fp,”<?xml version=”1.0″ encoding=”utf-8″?>rn”);
fputs(fp,”<this->dbname>rn”);
for(i=0;i<count(array);i++){
fputs(fp,”<this->dbtable>rn”);
xml.=”<this->dbtable>rn”;
foreach(array[i] as k=>s){
fputs(fp,”<k>s</k>rn”);
}
fputs(fp,”</this->dbtable>rn”);
}
fputs(fp,”</this->dbname>”);
fclose(fp);
}
}
?>