如何将SELECT + WHERE查询与INSERT查询结合在一起? [英] How do I combine a SELECT + WHERE query with an INSERT query?

问题描述

我想结合以下两个查询，有人可以给我一个方法吗? (仅当SELECT查询产生结果时，INSERT查询才应运行)

I want to combine the two following queries, can anyone give me a idea how to do that? (the INSERT query should run only if the SELECT query has a result)

查询1号:

INSERT IGNORE INTO senders(
sender_id,
telephone,
)
VALUES ( 1, 0723355888)

查询2号:

SELECT student_name
FROM students
WHERE student_id =1

推荐答案

INSERT INTO senders (sender_id, telephone)
SELECT student_id, student_telephone FROM students
WHERE student_id = 1
LIMIT 1

或如果Telefone不属于Students表的一部分，则对其进行硬编码: 之所以可行，是因为如果查询为0行，则根本不执行插入操作.

or if telefone is not a part of the students table, hard code it: This works because if the query 0 rows, no insert is performed at all.

INSERT INTO senders (sender_id, telephone)
SELECT 1, 0723355888 FROM students
WHERE student_id = 1
LIMIT 1

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