INSERT INTO registration( name, email, username) values('eswar',(select email from registration),'manikandan')
正确的语法如下:
INSERT INTO registration( name, email, username)
SELECT 'eswar', email, 'manikandan' FROM registration
这将插入n行(注册表中的行数)。
若要对此进行筛选,请在select语句中添加一个约束。
INSERT INTO registration( name, email, username)
SELECT 'eswar', email, 'manikandan' FROM registration WHERE email="x@yahoo.com"
您可以将常数值添加到SELECT语句中,而不是相反。
为什么不简单地使用更新查询
UPDATE registration SET name='eswar', username = 'manikandan' WHERE email = 'email@mail.com'