如何用新行在同一張表上插入不同的值？

Question

INSERT INTO registration(name, email, username) values('eswar',(select email from registration),'manikandan') 

Answer 1

正確的語法是這樣的：

INSERT INTO registration(name, email, username) 
SELECT 'eswar', email, 'manikandan' FROM registration 

這會插入n行（在登記表的行數）。

要篩選此選項，請在select語句中添加一個約束。

INSERT INTO registration(name, email, username) 
SELECT 'eswar', email, 'manikandan' FROM registration WHERE email="x@yahoo.com" 

您將常數值添加到SELECT語句而不是其他方式。

Answer 2

你爲什麼不乾脆使用更新查詢

UPDATE registration SET name='eswar', username = 'manikandan' WHERE email = 'email@mail.com'