mysql 查询一个表部分字段，然后插入另一个表中

现有表jcs_food_distribution，jcs_food，从jcs_food中查询food_code,enterprise_code，将其插入到jcs_food_distribution中

INSERT INTO jcs_food_distribution (food_code, enterprise_code) SELECT    food_code,    enterprise_codeFROM    jcs_food

如果只需要导入jcs_food_distribution中不存在的记录，可以用

INSERT INTO jcs_food (food_code, enterprise_code) SELECT    food_code,    enterprise_codeFROM    jcs_foodWHERE    NOT EXISTS (        SELECT           food_code        FROM            jcs_food_distribution        WHERE            jcs_food_distribution.food_code = jcs_food.food_code    )