重新封装的PHPLib DB类（推荐简单项目使用本类库）
重新封装的PHPLib DB类（推荐简单项目使用本类库）
重新封装的PHPLib DB类 （推荐简单项目使用本类库）
为了便于自己的开发，但是又不想使用ADODB、PEAR::DB这样的庞然大物，就在PHPLib DB类的基础上、参考PEAR::DB类，封装了自己的DB类，简单好使，非常方便。目前只针对MySQL有效，没什么技术含量，姑且为参考。
使用本类库只是需要把下面代码保存为database.inc.php或者database.class.php，在自己需要的地方include进来，然后实例化对象，然后调用连接方法，最后在执行操作。
[ 连接数据库 ]
//包含数据库处理类文件
include_once('database.inc.php');
//本地数据库配置
define('DB_HOST', 'localhost'); //数据库服务器
define('DB_USER_NAME', 'root'); //数据库用户名
define('DB_USER_PASS', ''); //密码
define('DB_DATABASE', 'test'); //数据库
//连接本地数据库
$db = new DB_Sql();
$db->connect(DB_DATABASE, DB_HOST, DB_USER_NAME, DB_USER_PASS);
[ 使用方法 ]
//获取所有记录
$sql = 'SELECT * FROM table1';
$all_record = $db->get_all($sql);
//获取一条
$sql = 'SELECT * FROM table1 WHERE id = '1'';
$one_row = $db->get_one($sql);
//分页查询，提取20条记录
$sql = 'SELECT * FROM table1';
$page_record = $db->limit_query($sql, $start=0, $offset=20, $order='ORDER BY id DESC');
//提取指定数目的记录
$sql = 'SELECT * FROM table1';
$limit_record = $db->get_limit($sql);
//统计记录数，统计所有类型为学生的
$count = $db->count('table1', 'id', 'type = 'student'');
//插入一条记录
$info_array = array(
'name' => 'heiyeluren',
'type' => 'student',
'age' => '22',
'gender' => 'boy'
);
$db->insert('table1', $info_array);
//更新一条记录
$info_array = array(
'name' => 'heiyeluren',
'type' => 'teacher',
'age' => '22',
'gender' => 'boy'
);
$db->update('table1', $info_array, 'name = 'heiyeluren'');
//删除记录
$db->delete('table1', 'name = 'heiyeluren'');
//执行一条无结果集的SQL
$db->execute('DELETE FROM table1 WHERE name = 'heiyeluren'');
[ 类库代码 ]
<?php
/**
* 文件: database.inc.php
* 描述: 数据库操作类
* 作者: heiyeluren
* 创建: 2005-12-25
* 修改: 2005-12-26
* 说明: 本库使用PHPLib DB库作为核心, 同时增加一些实用方法, 详细参考注释
*/
class DB_Sql
{
/* public: connection parameters */
var $Host = '';
var $Database = '';
var $User = '';
var $Password = '';
/* public: configuration parameters */
var $Auto_Free = 1; ## Set to 1 for automatic mysql_free_result()
var $Debug = 0; ## Set to 1 for debugging messages.
var $Halt_On_Error = 'yes'; ## 'yes' (halt with message), 'no' (ignore errors quietly), 'report' (ignore errror, but spit a warning)
var $PConnect = 0; ## Set to 1 to use persistent database connections
var $Seq_Table = 'db_sequence';
/* public: result array and current row number */
var $Record = array();
var $Row;
/* public: current error number and error text */
var $Errno = 0;
var $Error = '';
/* public: this is an api revision, not a CVS revision. */
var $type = 'mysql';
//var $revision = '1.2';
/* private: link and query handles */
var $Link_ID = 0;
var $Query_ID = 0;
var $locked = false; ## set to true while we have a lock
/* public: constructor */
function DB_Sql() {
$this->query($query);
}
/* public: some trivial reporting */
function link_id() {
return $this->Link_ID;
}
function query_id() {
return $this->Query_ID;
}
/* public: connection management */
function connect($Database = '', $Host = '', $User = '', $Password = '') {
/* Handle defaults */
if ('' == $Database)
$Database = $this->Database;
if ('' == $Host)
$Host = $this->Host;
if ('' == $User)
$User = $this->User;
if ('' == $Password)
$Password = $this->Password;
/* establish connection, select database */
if ( 0 == $this->Link_ID ) {
if(!$this->PConnect) {
$this->Link_ID = mysql_connect($Host, $User, $Password);
} else {
$this->Link_ID = mysql_pconnect($Host, $User, $Password);
}
if (!$this->Link_ID) {
$this->halt('connect($Host, $User, \$Password) failed.');
return 0;
}
if (!@mysql_select_db($Database,$this->Link_ID)) {
$this->halt('cannot use database '.$Database);
return 0;
}
}
return $this->Link_ID;
}
/* public: discard the query result */
function free() {
@mysql_free_result($this->Query_ID);
$this->Query_ID = 0;
}
/* public: perform a query */
function query($Query_String) {
/* No empty queries, please, since PHP4 chokes on them. */
if ($Query_String == '')
/* The empty query string is passed on from the constructor,
* when calling the class without a query, e.g. in situations
* like these: '$db = new DB_Sql_Subclass;'
*/
return 0;
if (!$this->connect()) {
return 0; /* we already complained in connect() about that. */
};
# New query, discard previous result.
if ($this->Query_ID) {
$this->free();
}
if ($this->Debug)
printf('Debug: query = %s<br>\n', $Query_String);
$this->Query_ID = @mysql_query($Query_String,$this->Link_ID);
$this->Row = 0;
$this->Errno = mysql_errno();
$this->Error = mysql_error();
if (!$this->Query_ID) {
$this->halt('Invalid SQL: '.$Query_String);
}
# Will return nada if it fails. That's fine.
return $this->Query_ID;
}
/* public: walk result set */
function next_record() {
if (!$this->Query_ID) {
$this->halt('next_record called with no query pending.');
return 0;
}
$this->Record = @mysql_fetch_array($this->Query_ID);
$this->Row += 1;
$this->Errno = mysql_errno();
$this->Error = mysql_error();
$stat = is_array($this->Record);
if (!$stat && $this->Auto_Free) {
$this->free();
}
return $stat;
}
/* public: position in result set */
function seek($pos = 0) {
$status = @mysql_data_seek($this->Query_ID, $pos);
if ($status)
$this->Row = $pos;
else {
$this->halt('seek($pos) failed: result has '.$this->num_rows().' rows.');
/* half assed attempt to save the day,
* but do not consider this documented or even
* desireable behaviour.
*/
@mysql_data_seek($this->Query_ID, $this->num_rows());
$this->Row = $this->num_rows();
return 0;
}
return 1;
}
/* public: table locking */
function lock($table, $mode = 'write') {
$query = 'lock tables ';
if(is_array($table)) {
while(list($key,$value) = each($table)) {
// text keys are 'read', 'read local', 'write', 'low priority write'
if(is_int($key)) $key = $mode;
if(strpos($value, ',')) {
$query .= str_replace(',', ' $key, ', $value) . ' $key, ';
} else {
$query .= '$value $key, ';
}
}
$query = substr($query, 0, -2);
} elseif(strpos($table, ',')) {
$query .= str_replace(',', ' $mode, ', $table) . ' $mode';
} else {
$query .= '$table $mode';
}
if(!$this->query($query)) {
$this->halt('lock() failed.');
return false;
}
$this->locked = true;
return true;
}
function unlock() {
// set before unlock to avoid potential loop
$this->locked = false;
if(!$this->query('unlock tables')) {
$this->halt('unlock() failed.');
return false;
}
return true;
}
/* public: evaluate the result (size, width) */
function affected_rows() {
return @mysql_affected_rows($this->Link_ID);
}
function num_rows() {
return @mysql_num_rows($this->Query_ID);
}
function num_fields() {
return @mysql_num_fields($this->Query_ID);
}
/* public: shorthand notation */
function nf() {
return $this->num_rows();
}
function np() {
print $this->num_rows();
}
function f($Name) {
if (isset($this->Record[$Name])) {
return $this->Record[$Name];
}
}
function p($Name) {
if (isset($this->Record[$Name])) {
print $this->Record[$Name];
}
}
/* public: sequence numbers */
function nextid($seq_name) {
/* if no current lock, lock sequence table */
if(!$this->locked) {
if($this->lock($this->Seq_Table)) {
$locked = true;
} else {
$this->halt('cannot lock '.$this->Seq_Table.' - has it been created?');
return 0;
}
}
/* get sequence number and increment */
$q = sprintf('select nextid from %s where seq_name = '%s'',
$this->Seq_Table,
$seq_name);
if(!$this->query($q)) {
$this->halt('query failed in nextid: '.$q);
return 0;
}
/* No current value, make one */
if(!$this->next_record()) {
$currentid = 0;
$q = sprintf('insert into %s values('%s', %s)',
$this->Seq_Table,
$seq_name,
$currentid);
if(!$this->query($q)) {
$this->halt('query failed in nextid: '.$q);
return 0;
}
} else {
$currentid = $this->f('nextid');
}
$nextid = $currentid + 1;
$q = sprintf('update %s set nextid = '%s' where seq_name = '%s'',
$this->Seq_Table,
$nextid,
$seq_name);
if(!$this->query($q)) {
$this->halt('query failed in nextid: '.$q);
return 0;
}
/* if nextid() locked the sequence table, unlock it */
if($locked) {
$this->unlock();
}
return $nextid;
}
/* public: return table metadata */
function metadata($table = '', $full = false) {
$count = 0;
$id = 0;
$res = array();
/*
* Due to compatibility problems with Table we changed the behavior
* of metadata();
* depending on $full, metadata returns the following values:
*
* - full is false (default):
* $result[]:
* [0]['table'] table name
* [0]['name'] field name
* [0]['type'] field type
* [0]['len'] field length
* [0]['flags'] field flags
*
* - full is true
* $result[]:
* ['num_fields'] number of metadata records
* [0]['table'] table name
* [0]['name'] field name
* [0]['type'] field type
* [0]['len'] field length
* [0]['flags'] field flags
* ['meta'][field name] index of field named 'field name'
* This last one could be used if you have a field name, but no index.
* Test: if (isset($result['meta']['myfield'])) { ...
*/
// if no $table specified, assume that we are working with a query
// result
if ($table) {
$this->connect();
$id = @mysql_list_fields($this->Database, $table);
if (!$id) {
$this->halt('Metadata query failed.');
return false;
}
} else {
$id = $this->Query_ID;
if (!$id) {
$this->halt('No query specified.');
return false;
}
}
$count = @mysql_num_fields($id);
// made this IF due to performance (one if is faster than $count if's)
if (!$full) {
for ($i=0; $i<$count; $i++) {
$res[$i]['table'] = @mysql_field_table ($id, $i);
$res[$i]['name'] = @mysql_field_name ($id, $i);
$res[$i]['type'] = @mysql_field_type ($id, $i);
$res[$i]['len'] = @mysql_field_len ($id, $i);
$res[$i]['flags'] = @mysql_field_flags ($id, $i);
}
} else { // full
$res['num_fields']= $count;
for ($i=0; $i<$count; $i++) {
$res[$i]['table'] = @mysql_field_table ($id, $i);
$res[$i]['name'] = @mysql_field_name ($id, $i);
$res[$i]['type'] = @mysql_field_type ($id, $i);
$res[$i]['len'] = @mysql_field_len ($id, $i);
$res[$i]['flags'] = @mysql_field_flags ($id, $i);
$res['meta'][$res[$i]['name']] = $i;
}
}
// free the result only if we were called on a table
if ($table) {
@mysql_free_result($id);
}
return $res;
}
/* public: find available table names */
function table_names() {
$this->connect();
$h = @mysql_query('show tables', $this->Link_ID);
$i = 0;
while ($info = @mysql_fetch_row($h)) {
$return[$i]['table_name'] = $info[0];
$return[$i]['tablespace_name'] = $this->Database;
$return[$i]['database'] = $this->Database;
$i++;
}
@mysql_free_result($h);
return $return;
}
/* private: error handling */
function halt($msg) {
$this->Error = @mysql_error($this->Link_ID);
$this->Errno = @mysql_errno($this->Link_ID);
if ($this->locked) {
$this->unlock();
}
if ($this->Halt_On_Error == 'no')
return;
$this->haltmsg($msg);
if ($this->Halt_On_Error != 'report')
die('Session halted.');
}
function haltmsg($msg) {
printf('</td></tr></table><b>Database error:</b> %s<br>\n', $msg);
printf('<b>MySQL Error</b>: %s (%s)<br>\n',
$this->Errno,
$this->Error);
}
//----------------------------------
// 模块: 自定义函数
// 功能: 部分实用的数据库处理方法
// 作者: heiyeluren
// 时间: 2005-12-26
//----------------------------------
/**
* 方法: execute($sql)
* 功能: 执行一条SQL语句，主要针对没有结果集返回的SQL
* 参数: $sql 需要执行的SQL语句，例如：execute('DELETE FROM table1 WHERE id = '1'')
* 返回: 更新成功返回True，失败返回False
*/
function execute($sql)
{
if (empty($sql))
{
$this->error('Invalid parameter');
}
if (!$this->query($sql))
{
return false;
}
return true;
}
/**
* 方法: get_all($sql)
* 功能: 获取SQL执行的所有记录
* 参数: $sql 需要执行的SQL,例如: get_all('SELECT * FROM Table1')
* 返回: 返回包含所有查询结果的二维数组
*/
function get_all($sql)
{
$this->query($sql);
$result_array = array();
while($this->next_record())
{
$result_array[] = $this->Record;
}
if (count($result_array)<=0)
{
return 0;
}
return $result_array;
}
/**
* 方法: get_one($sql)
* 功能: 获取SQL执行的一条记录
* 参数: $sql 需要执行的SQL,例如: get_one('SELECT * FROM Table1 WHERE id = '1'')
* 返回: 返回包含一条查询结果的一维数组
*/
function get_one($sql)
{
$this->query($sql);
if (!$this->next_record())
{
return 0;
}
return $this->Record;
}
/**
* 方法: get_limit($sql, $limit)
* 功能: 获取SQL执行的指定数量的记录
* 参数:
* $sql 需要执行的SQL,例如: SELECT * FROM Table1
* $limit 需要限制的记录数
* 例如 需要获取10条记录, get_limit('SELECT * FROM Table1', 10);
*
* 返回: 返回包含所有查询结果的二维数组
*/
function get_limit($sql, $limit)
{
$this->query($sql);
$result_array = array();
for ($i=0; $i<$limit&&$this->next_record(); $i++)
{
$result_array[] = $this->Record;
}
if (count($result_array) <= 0)
{
return 0;
}
return $result_array;
}
/**
* 方法: limit_query($sql, $start=0, $offset=20, $order='')
* 功能: 为分页的获取SQL执行的指定数量的记录
* 参数:
* $sql 需要执行的SQL,例如: SELECT * FROM Table1
* $start 记录的开始数, 缺省为0
* $offset 记录的偏移量，缺省为20
* $order 排序方式，缺省为空，例如：ORDER BY id DESC
* 例如 需要获取从0到10的记录并且按照ID号倒排, get_limit('SELECT * FROM Table1', 0, 10, 'ORDER BY id DESC');
*
* 返回: 返回包含所有查询结果的二维数组
*/
function limit_query($sql, $start=0, $offset=20, $order='')
{
$sql = $sql .' $order LIMIT $start,$offset';
$this->query($sql);
$result = array();
while($this->next_record())
{
$result[] = $this->Record;
}
if (count($result) <=0 )
{
return 0;
}
return $result;
}
/**
* 方法: count($table,$field='*', $where='')
* 功能: 统计表中数据总数
* 参数:
* $table 需要统计的表名
* $field 需要统计的字段，默认为*
* $where 条件语句，缺省为空
* 例如 按照ID统计所有年龄小于20岁的用户, count('user_table', 'id', 'user_age < 20')
*
* 返回: 返回统计结果的数字
*/
function count($table,$field='*', $where='')
{
$sql = (empty($where) ? 'SELECT COUNT($field) FROM $table' : 'SELECT COUNT($field) FROM $table WHERE $where');
$result = $this->get_one($sql);
if (!is_array($result))
{
return 0;
}
return $result[0];
}
/**
* 方法: insert($table,$dataArray)
* 功能: 插入一条记录到表里
* 参数:
* $table 需要插入的表名
* $dataArray 需要插入字段和值的数组，键为字段名，值为字段值，例如：array('user_name'=>'张三', 'user_age'=>'20岁');
* 例如 比如插入用户张三，年龄为20, insert('users', array('user_name'=>'张三', 'user_age'=>'20岁'))
*
* 返回: 插入记录成功返回True，失败返回False
*/
function insert($table,$dataArray)
{
if (!is_array($dataArray) || count($dataArray)<=0)
{
$this->error('Invalid parameter');
}
while(list($key,$val) = each($dataArray))
{
$field .= '$key,';
$value .= ''$val',';
}
$field = substr($field, 0, -1);
$value = substr($value, 0, -1);
$sql = 'INSERT INTO $table ($field) VALUES ($value)';
if (!$this->query($sql))
{
return false;
}
return true;
}
/**
* 方法: update($talbe, $dataArray, $where)
* 功能: 更新一条记录
* 参数:
* $table 需要更新的表名
* $dataArray 需要更新字段和值的数组，键为字段名，值为字段值，例如：array('user_name'=>'张三', 'user_age'=>'20岁');
* $where 条件语句
* 例如 比如更新姓名为张三的用户为李四，年龄为21
* update('users', array('user_name'=>'张三', 'user_age'=>'20岁'), 'user_name='张三'')
*
* 返回: 更新成功返回True，失败返回False
*/
function update($talbe, $dataArray, $where)
{
if (!is_array($dataArray) || count($dataArray)<=0)
{
$this->error('Invalid parameter');
}
while(list($key,$val) = each($dataArray))
{
$value .= '$key = '$val',';
}
$value = substr($value, 0, -1);
$sql = 'UPDATE $talbe SET $value WHERE $where';
if (!$this->query($sql))
{
return false;
}
return true;
}
/**
* 方法: delete($table, $where)
* 功能: 删除一条记录
* 参数:
* $table 需要删除记录的表名
* $where 需要删除记录的条件语句
* 例如 比如要删除用户名为张三的用户，delete('users', 'user_name='张三'')
*
* 返回: 更新成功返回True，失败返回False
*/
function delete($table, $where)
{
if (empty($where))
{
$this->error('Invalid parameter');
}
$sql = 'DELETE FROM $table WHERE $where';
if (!$this->query($sql))
{
return false;
}
return true;
}
/**
* 方法: error($msg='')
* 功能: 显示错误信息后中止脚本
* 参数: $msg 需要显示的错误信息
* 返回: 无返回
*/
function error($msg='')
{
echo '<strong>Error</strong>: $msg\n<br>\n';
exit();
}
/**
* 方法：get_insert_id()
* 功能：获取最后插入的ID
* 参数: 无参数
* 返回：关闭成功返回ID，失败返回0
*/
function get_insert_id()
{
return mysql_insert_id($this->Link_ID);
}
/**
* 方法：close()
* 功能：关闭当前数据库连接
* 参数: 无参数
* 返回：关闭成功返回true，失败返回false
*/
function close()
{
return mysql_close($this->Link_ID);
}
}
?>
