MySQL

Question

我正在使用 Node.js。我使用 mysql 和 bluebird 包。

const pool = mysql.createPool({ ... });

const query = (stmt, params) => {
    return Promise.promisify(pool.query, { context: pool })(stmt, params);
};

const params = { ... };

const stmt = 'insert into table set ? on duplicate key update ?';

return query(stmt, [params, params])
    .then(results => {
        // I want to know actually what is done, insert or update
    });

Answer 1

return 对象中应该有一个键 affectedRows。从引用看，affectedRows插入时为1，更新时为0或2。

return query(stmt, [params, params])
    .then(results => {
        // I want to know actually what is done, insert or update
        if (results.affectedRows === 1) {
            // inserted
        } else {
            // updated
        }
    });

For INSERT ... ON DUPLICATE KEY UPDATE statements, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values. If you specify the CLIENT_FOUND_ROWS flag, the affected-rows value is 1 (not 0) if an existing row is set to its current values.

参考：https://dev.mysql.com/doc/refman/8.0/en/mysql-affected-rows.html

Answer 2

虽然我对节点的这一点不那么精通api，但基本原理是一样的：

query(stmt, [params.col1, params.col2])
.then(results => {
    Console.log("Affected rows: " + results.affectedRows);
});

现在，真正的问题是 MySQL 热衷于返回垃圾诊断信息。如果您修改超过 1 行，您将不知道每一行发生了什么，thanks to this:

With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current values.

如果你负担得起，一次一个地执行这些语句，并检查受影响的行数。否则，我正在挖掘一些 MySQL 内部函数，但我没有看到太多。

附带说明一下，您那里的通配符用得太过火了。相反，使用 space 到 update/insert 你想要的列，并参数化输入值：

-- Please don't name it 'table'
INSERT INTO my_table (column1, column2)
    VALUES (?, ?)
ON DUPLICATE KEY UPDATE column1 = VALUES(column1), column2 = VALUES(column2)

MySQL - insert into... on duplicate key update - 如何区分插入或更新？

MySQL - insert into... on duplicate key update - How to distinguish between insert or update?

node.js

node-mysql