Question

我有一个我正在使用的查询在MySQL中工作正常，但在Postgres上工作有问题。我收到语法错误，我确信它有一个简单的解决方案，但无法在此处找到任何相关信息。

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

我回来的错误：

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"来转义包含数字的标识符（在您的情况下，列名称）：

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

在PostgreSQL查询中转义列名中的字符？

1 个答案: