如何在SQL

Question

使用GROUP BY我有2個表（道路+負載），我想做出這個動作：

sprintf(my_cmd, 
"SELECT road.id 
FROM road,load " 
"WHERE road.id=load.id ORDER BY road.id " 
"GROUP BY road.id"); 

，但我得到一個錯誤：

Error executing query: ERROR: syntax error at or near "GROUP" LINE 1: ... road,load WHERE road.id=load.id ORDER BY road.id GROUP BY r...

爲什麼那？謝謝！

Answer 1

ORDER BY來GROUP BY後：

sprintf(my_cmd, 
"SELECT road.id 
FROM road,load " 
"WHERE road.id=load.id GROUP BY road.id " 
"ORDER BY road.id");