MySQL的內部連接 ​​- 不返回任何結果

Question

我有兩個MySQL數據庫的表名爲客戶和訂單，一個樣品低於...

customers 
client_id | cust_name | cust_phone 
-------------------------------- 
8273  | Mr Jones | 382749584 
38  | Mr Smith | 773625372 
9   | Mrs Brown | 922382938 

orders 
order_id | cust_id | product_id 
-------------------------------- 
392  | 9  | 9388 
23  | 2837  | 9283 
488  | 17  | 28392 

我試圖做一個INNER JOIN這樣的...

SELECT * FROM customers 
JOIN orders 
ON customers.cust_id=orders.client_id 
WHERE ('client_id' LIKE '9') 

它不返回任何結果，但我期待它給我顯示的9

的CLIENT_ID我要去哪裏錯了領域？

Answer 1

我想你在這裏犯的錯誤「CLIENT_ID」

SELECT * FROM customers 
JOIN orders 
ON customers.cust_id=orders.client_id 
WHERE client_id LIKE '9' 

，如果你寫「」這是需要作爲字符串

Answer 2

您的查詢是錯誤的。

SELECT * FROM customers 
JOIN orders 
ON customers.client_id =orders.cust_id 
WHERE ('client_id' LIKE '9') 

列client_id不orders表中。使用client_id = 9而不是like查詢。

Answer 3

嘗試這一個完全匹配

SELECT * FROM customers JOIN orders ON customers.cust_id=orders.client_id WHERE orders.client_id = 9 

或像

SELECT * FROM customers JOIN orders ON customers.cust_id=orders.client_id WHERE orders.client_id Like '9' 

通配符可以在這裏使用例如

'%9%' 
'9%'