在PostgreSQL查询的列名中转义字符？

Question

我有一个查询，我正在使用，在MySQL中工作正常，但在Postgres上有问题。我收到了一个语法错误，我确信它有一个简单的解决方案，但在这里找不到任何有关它的信息。

很明显，问题与第一种情况下的数字1有关。

SELECT *, 
(
(case when 1stFarmers > 0 THEN 1 ELSE 0 END) + 
    (case when OldMcDonald > 0 THEN 1 ELSE 0 END) + 
    (case when NewMcDonald > 0 THEN 1 ELSE 0 END) 

) as num_fruits 

FROM (SELECT 
    fruit, sum(farmers), 
    sum(case when farmer = '1stFarmers' then harvest_count else 0 end) AS 1stFarmers, 
    sum(case when farmer = 'OldMcDonald' then harvest_count else 0 end) AS Old_McDonald, 
    sum(case when farmer = 'NewMcDonald' then harvest_count else 0 end) AS New_McDonald 
FROM fruits 
GROUP BY 
    farmer) ft 

---

错误我取回：

syntax error at or near "stFarmers" 
    Position: 27 
(
(case when 1stFarmers > 0 THEN 1 ELSE 0 END) + 
      ^
    (case when OldMcDonald > 0 THEN 1 ELSE 0 END) + 

Answer 1

使用双引号"逃脱标识符（在你的情况下，列名）包含数字：

(case when "1stFarmers" > 0 THEN 1 ELSE 0 END) +