MySQL: INSERT Data if no record found in SELECT 语句

Question

如果在单个查询中 table 中找不到记录，我可以插入数据吗？？ (如果YES/NO,请指导)

示例

SELECT * FROM CITIES ct WHERE ct.city = 'Any City Name';

如果上述查询 returns 零 [0 ] 记录，则必须执行以下查询：

INSERT INTO CITIES (city) VALUES ('Any City Name');
SELECT * FROM CITIES ct WHERE ct.city = 'Any City Name'

Answer 1

你可以试试这个：

INSERT INTO CITIES (city) 
SELECT 'Any City Name' 
FROM cities
WHERE NOT EXISTS (SELECT * FROM CITIES WHERE city = 'Any City Name') LIMIT 1;

MySQL: INSERT Data if no record found in SELECT Statement