这个mysql查询有什么问题？

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 

错误：

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

，你需要选择的东西（一个表，说）

Answer 2

你错过了 “FROM” 子句前的 “WHERE”。

SELECT app_contracts。*，app_customers.id作为客户，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

这一个必须工作：

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

您还没有指定从中选择数据的表（一个或多个）。它应该是更加的形式：

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 ...指定由三个表应当与按键。

Answer 5

没有FROM子句