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我正在试用 Scriptella，看看它是否能满足我的需求。到目前为止，它似乎是一个很棒的工具。我花了几个小时研究示例脚本、搜索论坛并尝试掌握嵌套查询/脚本的窍门。

这是我的 ETL 文件的一个示例，为简洁起见稍微清理了一下。添加以 # 开头的行，而不是实际 ETL 文件的一部分。我正在尝试插入/检索 ID，然后将它们传递给以后的脚本块。最有希望的方法似乎是使用全局变量，但在尝试检索值时我得到了 null。稍后，我将在脚本块中添加代码，在将字段添加到数据库之前解析和显着转换字段。

没有错误。我只是没有得到我期望的操作系统 ID 和类别 ID。先感谢您。

<!DOCTYPE etl SYSTEM "http://scriptella.javaforge.com/dtd/etl.dtd">
<etl>
    <connection id="in" driver="csv" url="mycsvfile.csv"/>
    <connection id="dest" url="jdbc:mysql://localhost:3306/pvm3" user="user" password="password"/>
    <connection id="js" driver="script"/>

    <query connection-id="in">
        <!-- all columns are selected, notably: OPERATINGSYSTEM, CATEGORY, QID, TITLE -->

        <query connection-id="dest">
            #Check to see if the OS already exists, and get the ID if it does
            select max(os_id) as os_id, count(*) as os_cnt from etl_os where os = ?OPERATINGSYSTEM;

            #If it doesnt exist then add it and get the auto_increment value
            <script if="os_cnt==0">
                insert into etl_os(os) values(?OPERATINGSYSTEM);

                <query connection-id="dest">
                    select last_insert_id() as os_id;

                    #Store in global so it can be accessed in later script blocks
                    <script connection-id="js">
                        etl.globals.put('os_id', os_id);
                    </script>
                </query>
            </script>

            #Same style select/insert as above for category_id (excluded for brevity)

            #See if KB record exists by qid, if not then add it with the OS ID and category ID we got earlier
            <query connection-id="dest">
                select max(qid) as existing_qid, count(*) as kb_cnt from etl_qids where qid = ?QID

                <script if="kb_cnt==0">
                    insert into etl_qids(qid, category_id, os_id) values (?QID, ?{etl.globals.get('category_id')}, ?{etl.globals.get('os_id')});
                </script>
            </query>

        </query>

    </query>
</etl>
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1 回答 1

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了解如何做到这一点。本质上，只需嵌套查询以在将数据传递给脚本之前对其进行修改。以下是解决方案的快速类型。起初我不明白查询可以立即嵌套以在将行传递给处理之前对其进行转换。我的印象也是只有脚本才能操纵数据。

（查询）原始数据 -> （查询）操作数据 -> （脚本）写入新数据。

.. in is a CSV file ..
.. js is a driver="script" block ..

<query connection-id="in">
    <query connection-id="js">
        //transform data as needed here
        if (BASE_TYPE == '-') BASE_TYPE = '0';
        if (SECONDARY_TYPE == '-') SECONDARY_TYPE = '0';
        SIZES = SIZES.toLowerCase();

        query.next(); //call nested scripts

        <script connection-id="db">
            INSERT IGNORE INTO sizes(size) VALUES (?SIZE);
            INSERT IGNORE INTO test(base_type,secondary_type) VALUES (?BASE_TYPE, ?SECONDARY_TYPE);
        </script>

    </query>
</query>
于 2015-03-16T21:25:34.183 回答