如果語句使用INSERT作為then子句（MYSQL）

Question

我正在做一個有條件的插入，但是我在做一個有困難。

條件是這樣的

if(select count(*) from employee < 3, insert into employee (name) values ("lisa");

Answer 1

您可以這樣嘗試：

SET some_var = (select count(*) from employee);

if(some_var < 3) then
    insert into employee (name) values ("lisa");
end if

或喜歡

SELECT COUNT(*) AS count into @some_var FROM employee;
if(@some_var < 3) then
    insert into employee (name) values ("lisa");
end if;

Answer 2

嘗試這個：

insert into employee(name)
    select 'lisa'
   where (select count(*) from employee) < 3;