C＃中的MySQL内连接语法错误

Question

谁知道为什么会出现语法错误？ 我觉得里面没有保留词吗？

C＃命令

cmd.CommandText = "SELECT ordertable._name, ordertable.quantity, food_menu.food_price, beverage_menu.beverage_price" +
                         "FROM ordertable" +
                         "INNER JOIN food_menu ON ordertable._name = food.foodname" +
                         "INNER JOIN beverage_menu ON beverage_menu.beverage_name' = ordertable._name" +
                         "WHERE ordertable.tablenum = '1'";

错误：

您的SQL语法有错误; 检查与您的MySQL服务器版本对应的手册，以便在'JOIN food_menu ON ordertable._name = food.foodnameINNER JOIN beverage_menu ON''第1行附近使用正确的语法

Answer 1

你错过了空间。 目前您的查询将像FROM ordertableINNER JOIN food_menu ... 您可以使用多行语法使其更简单

cmd.CommandText = @"SELECT ordertable._name, ordertable.quantity, food_menu.food_price, beverage_menu.beverage_price
                         FROM ordertable
                         INNER JOIN food_menu ON ordertable._name = food_menu.foodname
                         INNER JOIN beverage_menu ON beverage_menu.beverage_name = ordertable._name
                         WHERE ordertable.tablenum = 1";

Answer 2

从字符串中删除不必要的串联，您收到错误，因为您的查询需要一些在加入之前未指定的空格。

cmd.CommandText = "SELECT ordertable._name, 
                          ordertable.quantity, 
                          food_menu.food_price,
                          beverage_menu.beverage_price 
                   FROM  ordertable
                   INNER JOIN food_menu 
                         ON ordertable._name = food.foodname
                   INNER JOIN beverage_menu 
                         ON beverage_menu.beverage_name = ordertable._name
                   WHERE ordertable.tablenum = 1";