无法编写SQL查询

我有一个存储优惠券id、限制值和限制类型的限制表

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我想返回一个查询，该查询提供适用于印度国家和德里市的优惠券。

您可以编写如下子查询

SELECT
*
FROM coupon_table
where id in (
      select coupon_id 
      from restriction_table
      where (restriction_value = 'Delhi' AND restriction_type = 'city')
            OR (restriction_value = 'India' AND restriction_type = 'country')
);

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分别查询每个条件，并验证是否存在相同的优惠券id：

SELECT DISTINCT a.coupon_id
FROM tableA a
JOIN (SELECT coupon_id FROM tableA WHERE restriction_value = 'delhi' AND restriction_type = 'city') b ON b.coupon_id = a.coupon_id
JOIN (SELECT coupon_id FROM tableA WHERE restriction_value = 'india' AND restriction_type = 'country') c ON c.coupon_id = a.coupon_id
WHERE b.coupon_id = c.coupon_id

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选择城市“德里”的优惠券，该城市有国家“印度”的记录。 大概是这样的：

SELECT city.*
FROM   my_table city
WHERE  city.restriction_type = 'city'
  AND  city.restriction_value = 'delhi'
  AND  EXISTS (SELECT *
               FROM   my_table country
               WHERE  city.coupon_id = country.coupon_id
                 AND  country.restriction_type = 'country'
                 AND  country.restriction_value = 'india');

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您好，欢迎来到Stack Overflow。请显示您的表DDL、示例数据、预期结果以及您尝试到的无效日期。没有这个,，我们无法真正帮助您。给定一张优惠券，请编写一个sql查询，给出以下结果：优惠券适用于印度国家和城市。优惠券是一个单独的表？如何通过限制表中的where条件。我正在更新我的答案。我在优惠券id 2中添加了一个示例表……这不是必需的因为第二条记录也有同样的数据来自德里市。您可以使其唯一，然后应用该条件。

SELECT city.*
FROM   my_table city
WHERE  city.restriction_type = 'city'
  AND  city.restriction_value = 'delhi'
  AND  EXISTS (SELECT *
               FROM   my_table country
               WHERE  city.coupon_id = country.coupon_id
                 AND  country.restriction_type = 'country'
                 AND  country.restriction_value = 'india');