PHP操作sqlite类

<?php

    class Sqlite {
        var $link;
        var $querynum = 0;

        /*连接Sqlite数据库，参数：dbname->数据库名字*/
        function Open($dbname) {
            if(!($this->link = @sqlite_open($dbname))) {
                $this->halt('Can not Open to Sqlite');
            }
        }

        /*执行sql语句，返回对应的结果标识*/
        function Query($sql) {
            $this->querynum++;
            if($query = @sqlite_query($this->link, $sql)) {
                return $query;
            } else {
                $this->halt('Sqlite Query Error', $sql);
            }
        }

        /*执行Insert Into语句，并返回最后的insert操作所产生的自动增长的id*/
        function Insert($table, $iarr) {
            $value = $this->InsertSql($iarr);
            $this->Query('INSERT INTO "' . $table . '" ' . $value);
            return sqlite_last_insert_rowid($this->link);
        }

        /*执行Update语句，并返回最后的update操作所影响的行数*/
        function Update($table, $uarr, $condition = '') {
            $value = $this->UpdateSql($uarr);
            if ($condition) {
                $condition = ' WHERE ' . $condition;
            }
            $this->Query('UPDATE "' . $table . '"' . ' SET ' . $value . $condition);
            return sqlite_changes($this->link);
        }

        /*执行Delete语句，并返回最后的Delete操作所影响的行数*/
        function Delete($table, $condition = '') {
            if ($condition) {
                $condition = ' WHERE ' . $condition;
            }
            $this->Query('DELETE "' . $table . '"' . $condition);
            return sqlite_changes($this->link);
        }

        /*将字符转为可以安全保存的sqlite值，比如a'a转为a''a*/
        /*
        function EnCode($str) {
            if (strpos($str, "\0") === false) {
                if (strpos($str, '\'') === false) {
                    return $str;
                } else {
                    return str_replace('\'', '\'\'', $str);
                }
            } else {
                $str = str_replace("\0", '', $str);
                if (strpos($str, '\'') === false) {
                return $str;
                } else {
                    return str_replace('\'', '\'\'', $str);
                }
            }
        }
        */
        function EnCode($str) {
            return sqlite_escape_string($str);
        }

        /*将可以安全保存的sqlite值转为正常的值，比如a''a转为a'a*/
        function DeCode($str) {
            if(strpos($str, '\'\'') === false) {
                return $str;
            } else {
                return str_replace('\'\'', '\'', $str);
            }
        }

        /*将对应的列和值生成对应的insert语句，如：array('id' => 1, 'name' => 'name')返回("id", "name") VALUES (1, 'name')*/
        function InsertSql($iarr) {
            if (is_array($iarr)) {
                $fstr = '';
                $vstr = '';
                foreach ($iarr as $key => $val) {
                    $fstr .= '"' . $key . '", ';
                    $vstr .= '\'' . $val . '\', ';
                }
                if ($fstr) {
                    $fstr = '(' . substr($fstr, 0, -2) . ')';
                    $vstr = '(' . substr($vstr, 0, -2) . ')';
                    return $fstr . ' VALUES ' . $vstr;
                } else {
                    return '';
                }
            } else {
                return '';
            }
        }

        /*将对应的列和值生成对应的insert语句，如：array('id' => 1, 'name' => 'name')返回"id" = 1, "name" = 'name'*/
        function UpdateSql($uarr) {
            if (is_array($uarr)) {
                $ustr = '';
                foreach ($uarr as $key => $val) {
                    $ustr .= '"' . $key . '" = \'' . $val . '\', ';
                }
                if ($ustr) {
                    return substr($ustr, 0, -2);
                } else {
                    return '';
                }
            } else {
                return '';
            }
        }

        /*返回对应的查询标识的结果的一行*/
        function GetRow($query, $result_type = SQLITE_ASSOC) {
            return sqlite_fetch_array($query, $result_type);
        }

        /*清空查询结果所占用的内存资源*/
        function Clear($query) {
            $query = null;
            return true;
        }

/*关闭数据库*/
        function Close() {
            return sqlite_close($this->link);
        }

        function halt($message = '', $sql = '') {
            $ei = sqlite_last_error($this->link);
            $message .= '<br />Sqlite Error: ' . $ei . ', ' . sqlite_error_string($ei);
            if ($sql) {
                $sql = '<br />sql:' . $sql;
            }
            exit('DataBase Error.<br />Message: ' . $message . $sql);
        }
    }
?>