這個mysql查詢有什麼問題？

Question

SELECT app_contracts.*, app_customers.id as customer, app_boards.id as board 
WHERE app_customers.id=app_contracts.customer_id 
AND app_boards.id=app_contracts.board_id 
ORDER BY app_contracts.id DESC 

錯誤：

Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE app_customers.id=app_contracts.customer_id AND app_boards.id=app_contracts' at line 2

Answer 1

，你需要選擇的東西（一個表，說）

Answer 2

你錯過了 「FROM」 子句前的 「WHERE」。

SELECT app_contracts。*，app_customers.id作爲客戶，如app_boards.id板
FROM app_customers，app_contracts
WHERE app_customers.id = app_contracts.customer_id
AND app_boards.id = app_contracts.board_id
ORDER BY您的WHERE子句前app_contracts.id DESC

Answer 3

這一個必須工作：

SELECT app_contracts.*, app_customers.id as customer, app_boards.id as board 
FROM app_customers, app_contracts, app_boards 
WHERE app_customers.id=app_contracts.customer_id 
AND app_boards.id=app_contracts.board_id 
ORDER BY app_contracts.id DESC 

Answer 4

您還沒有指定從中選擇數據的表（一個或多個）。它應該是更加的形式：

SELECT app_contracts.*, app_customers.id as customer, app_boards.id as board 
FROM app_contracts, app_customers, app_boards 
JOIN ... 
WHERE app_customers.id=app_contracts.customer_id 
AND app_boards.id=app_contracts.board_id 
ORDER BY app_contracts.id DESC 

凡JOIN ...指定由三個表應當與按鍵。

Answer 5

沒有FROM子句