使用SQL关键字作为列的别名

Question

我正在执行以下查询，但它给出了语法错误。因为关键字key已在SQL中注册

SELECT `id` AS key, `country_name` AS value FROM countries

我也尝试使用这样的括号，但它不起作用：

SELECT `id` AS [key], `country_name` AS value FROM countries

如何处理？

Answer 1

使用反引号（`）或单引号（＆＃39;）在MySQL中为列提供别名。

试试这个：

SELECT `id` AS 'key', `country_name` AS value 
FROM countries;

或

SELECT `id` AS `key`, `country_name` AS value 
FROM countries;

Answer 2

key是mysql关键字，所以编译器假设为mysql关键字，你应该用撇号（`）转换为列名

SELECT `id` AS `key`, `country_name` AS value 
FROM countries