MySQL的触发器，模糊的语法错误

Question

使用MySQL 5.5，以下触发被拒一个错误：

create trigger nodups 
before insert on `category-category` 
for each row 
begin 
    if(catid >= relatedid) then 
     signal 'catid must be less than relatedid'; 
    end if 
end; 

，我发现了以下错误：

ERROR 1064 (42000): 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 '-category for each row begin if(catid >= relatedid) then signal 'catid must be l' at line 1

什么是错的这个触发器的语法？

对于它的价值，我只是想阻止插入与catid >= relatedid。我愿意接受实现这一目标的其他方法。

---

编辑： 上述被在一行上，分号和所有输入的查询。

我用分隔符重新尝试了一遍。这里是结果：

mysql> delimiter ### 
mysql> create trigger nodups 
    -> before insert on `category-category` 
    -> for each row 
    -> begin 
    -> if(catid >= relatedid) then 
    -> signal 'catid must be less than relatedid'; 
    -> end if 
    -> end; 
    -> ### 
ERROR 1064 (42000): 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 ''catid must be less than relatedid'; 
end if 
end' at line 6 

Answer 1

-是一个特殊字符。您需要使用反向引号来跳过包含特殊字符的表格

delimiter | 
create trigger nodups 
before insert on `category-category` 
for each row 
begin 
    if(catid >= relatedid) then 
     SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'catid must be less than relatedid'; 
    end if; 
end; 
| 
delimiter 

您还需要更改分隔符。否则数据库认为你的触发器定义在第一个;结束，这将是不完整的。

Answer 2

最明显的问题是category-category不是有效的标识符。将其列入反引号：

create trigger nodups 
before insert on `category-category` 
. . .