如何根据条件插入? [英] How to INSERT based on a condition?

问题描述

我有以下这些INSERT查询:

$db->prepare("INSERT INTO
              events (post_id, table_code, other_id, user_id, author_id, date_time )
              VALUES (?      , 15        , ?       , ?      , ?        , UNIX_TIMESTAMP()),
                     (?      , 15        , ?       , ?      , ?        , UNIX_TIMESTAMP())
")->execute(array($answer_id, $answer_id, $author_ques_id, $author_ques_id,
                  $answer_id, $answer_id, $author_ques_id, $author_ans_id));

如您所见，上面的查询在events表中插入了两行.现在，我需要在第二行的路上加一个条件.我的意思是，如果$condition是 true ，则插入第二行，否则不应该插入第二行. (始终应插入第一行).

As you see, query above inserts two rows into events table. Now I need to put a condition on the way of second row. I mean if $condition is true then inserts second rows, else it shouldn't insert second row. (first row always should be inserted).

注意: $condition始终包含布尔值.

那么，如何在第二行插入的方式上添加该条件?

Well, how can I put that condition on the way of second row inserting?

推荐答案

您可以使用insert select语句，如下所示:

You could use a insert select statement like this:

$db
->prepare("INSERT INTO
             events (post_id, table_code, other_id, user_id, author_id, date_time )
             select ?, 15, ?, ?, ?, UNIX_TIMESTAMP()
              UNION ALL
             select ?, 15, ?, ?, ?, UNIX_TIMESTAMP()
               from (select 1) as a
              where 1=?
")->execute(array($answer_id, $answer_id, $author_ques_id, $author_ques_id,
                  $answer_id, $answer_id, $author_ques_id, $author_ans_id,
                  ($yourCondition?1:0) ));

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