在类中使用变量 [英] Use of variables in classes

问题描述

我写了一个简单的类，它将MySQL SELECT查询放在一起，

允许你扩展查询，但我不确定何时使用$ this - >

var_name，当我可以使用$ varname时，以及何时需要使用

''var $ varname''，当这可以省略时。

这是'班级 - 可以变得更简单吗？

Michael


class select_query_builder {

//放在一起并添加到选择查询的类

var $ query;

var $ select;

var $ from ;

var $ where;

var $ orderby;

var $ distinct;

var $ t_select; < br $>
var $ t_from;

var $ t_where;

var $ t_orderby;


函数select_query_builder（ $ select，$ from，$ where =''''，$ orderby =''''）{

//每个变量都是一个数组


$ this - > select = $ select;

$ this - > from = $ from;

$ this - > where = $ where;

$ this - > orderby = $ orderby;


$ this - > t_select = $ select;

$ this - > t_from = $ from;

$ this - > t_where = $ where;

$ this - > t_orderby = $ orderby;

}


//在查询中添加其他元素

函数extend_query（$ what，$ newinfo ）

{

$ this - > {'t _''。$ what} = array_merge（$ this - > {''t _''。$ what}，$ newinfo）;

}


//返回完整的查询;

函数return_query（）{

$ this - > query =''SELECT''$ this - >不同。''''.implode（''，''，$ this - >

t_select）。''FROM''。implode（''，''，$ this - > t_from）;


if（！empty（$ this - > t_where））{

$ this - >查询。=''在哪里'.implode（''AND''，$ this - > t_where）;

}


if（！empty （$ this - > orderby））{

$ this - > query。=''ORDER BY''。implode（''ASC，''，$ this - > t_orderby）。''

ASC'';

}


返回$ this - >查询;


}


函数reset_to_before_extend（）{


$ this - > t_select = $ this - >选择;

$ this - > t_from = $ this - >来自;

$ this - > t_where = $ this - > where;

$ this - > t_orderby = $ this - > orderby;

}

}

I''ve written a simple class that puts together a MySQL SELECT query and
allows you to extend the query, but I''m unsure as to when to use $this - >
var_name and when I can just use $varname, and when it''s necessary to use
''var $varname'' and when this can be left out.
Here''s the class - could it be made simpler?
Michael

class select_query_builder {
// class to put together and add to a select query
var $query;
var $select;
var $from;
var $where;
var $orderby;
var $distinct;
var $t_select;
var $t_from;
var $t_where;
var $t_orderby;

function select_query_builder($select, $from, $where='''', $orderby ='''') {
// each variable is an array

$this -> select = $select;
$this -> from = $from;
$this -> where = $where;
$this -> orderby = $orderby;

$this -> t_select = $select;
$this -> t_from = $from;
$this -> t_where = $where;
$this -> t_orderby = $orderby;
}

// add additional elements to the query
function extend_query($what, $newinfo)
{
$this -> {''t_''.$what} = array_merge($this -> {''t_''.$what}, $newinfo);
}

// return the complete query;
function return_query() {
$this -> query = ''SELECT ''$this -> distinct.'' ''.implode('', '', $this ->
t_select).'' FROM ''.implode('', '', $this -> t_from);

if (!empty($this -> t_where)) {
$this -> query .= '' WHERE ''.implode('' AND '', $this -> t_where);
}

if (!empty($this -> orderby)) {
$this -> query .= '' ORDER BY ''.implode('' ASC, '', $this -> t_orderby).''
ASC'';
}

return $this -> query;

}

function reset_to_before_extend() {

$this -> t_select = $this -> select;
$this -> t_from = $this -> from;
$this -> t_where = $this -> where;
$this -> t_orderby = $this -> orderby;
}
}

推荐答案

this - >

var_name当我可以使用

this - >
var_name and when I can just use

varname时，以及何时需要使用

''var

varname, and when it''s necessary to use
''var

varname''什么时候可以省略。

这里是班级 - 可以变得更简单吗？

Michael


class select_query_builder {

//要放在一起并添加到选择查询的类

var

varname'' and when this can be left out.
Here''s the class - could it be made simpler?
Michael

class select_query_builder {
// class to put together and add to a select query
var

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