如何将SelectQuery对象转换为SQL字符串？ [英] How to convert SelectQuery object to SQL string?

问题描述

我设法使用__toString（）魔术方法打印一个字符串，但是在这个字符串中，我看到占位符（对于条件参数），并且它不能用作SQL查询。

I managed to print a string using __toString() magic method, but in this string I see placeholders (for conditions params), and it doesn't work as SQL query.

我检查过文档这个对象也是google，但是找不到工作的答案。

I checked documentation of this object, and also looked in google, but couldn't find a working answer.

推荐答案

根据问题的意见（谢谢@Scuzzy的灵感）我写了一些简单的代码来转换 SelectQuery 对象：

Basing on question's comments (thanks @Scuzzy for inspiration) I wrote some simple piece of code to convert SelectQuery object:

class ExportableSelectQuery {

    public static function toSql(SelectQuery $obj) {

        $_string = $obj->__toString();
        $_conditions = $obj->conditions();
        $_tables = $obj->getTables();
        $_fields = $obj->getFields();

        foreach($_tables as $k => $t) {
            if(!empty($t['alias'])) {
                $_string = str_replace('{' . $t['table'] . '}', $t['table'] . ' as', $_string);
            }
            else {
                $_string = str_replace('{' . $t['table'] . '}', $t['table'], $_string);
            }
        }

        foreach($_conditions as $k => $c) {
            if(is_int($c['value'])) {
                $_string = str_replace(':db_condition_placeholder_' . $k, $c['value'], $_string);
            }
            else {
                $_string = str_replace(':db_condition_placeholder_' . $k, "'" . $c['value'] . "'", $_string);
            }
        }

        //echo('<pre>');
        //var_dump($_fields);
        //var_dump($_conditions);
        //var_dump($_tables);
        //var_dump($_string);
        //echo('</pre>');
        //die();

        return $_string;
    }
}

此代码的使用现在很简单（如果只有$ SelectQuery 对象某处）：

Usage of this code is now simple (if you only have SelectQuery object somewhere):

die(ExportableSelectQuery::toSql($query));

我正在考虑扩展原始 SelectQuery 对象，并提供获取SQL代码的方法，但Drupal的 db_select 函数返回 SelectQuery ，所以我必须更改 db_select 函数或将返回的对象转换为 ExportableSelectQuery 。

I was thinking about extending original SelectQuery object, and provide method to get SQL code, but Drupal's db_select function returns SelectQuery, so I will have to either change db_select function or cast returned object to ExportableSelectQuery.

还这可能不是我可以写的最好的解决方案，但是假设时间和目的的限制解决了我的问题，只要罚款。

Also this is not probably best solution I could write, but assuming limit of time and purpose it solved my problem just fine.

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