如何在单个查询中使用While循环编写多个查询？

Question

我有两个与while循环相关的查询。我想在一个查询中进行。以下是我的代码

% root for f(x) = cos(x)

%% Define parameters
paso = 0.5e-10;
N = 100;
x = 1.0; 
i = 1;
eps = 1;
root_delta = 4.6; 

%% Allocate arrays
it = [];
error_data = [];

%% Generate data
while eps >= paso && i <= N  
    y = x - (cos(x)/(-sin(x)));
    eps = abs(y-x);
    x = y;
    error_delta(i) = abs(root_delta - x); %#ok<SAGROW>
    it(i) = i; %#ok<SAGROW>
    i = i + 1;
end

%% Plot data
figure(1);
semilogy(it,error_delta);
xlabel('Iterations');
ylabel('Error \delta');

Answer 1

您需要JOIN。

SELECT a.*
FROM faq a
     INNER JOIN faq_cat b ON a.fk_faq_cat_id = b.faq_cat_id
WHERE a.faq_status=1 AND b.faq_cat_status=1

这是关于SQL Join的指南。