重新封装的PHPLib DB类（推荐简单项目使用本类库）

技术2022-05-11 128

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 /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>Database error: %s /n", $msg); printf("MySQL Error: %s (%s) /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 "Error: $msg/n /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); } }?>

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