PostgreSQL GROUP BY
GROUP BY 分组聚合：SELECT 中出现的非聚合列必须都在 GROUP BY 里（PostgreSQL 强制检查）。
Key PointsPostgreSQL,GROUP BY,分组,聚合
讲解
GROUP BY 分组聚合：SELECT 中出现的非聚合列必须都在 GROUP BY 里（PostgreSQL 强制检查）。
示例
SQL
SELECT age, count(*) AS cnt FROM company GROUP BY age;讲解
GROUP BY 分组聚合：SELECT 中出现的非聚合列必须都在 GROUP BY 里（PostgreSQL 强制检查）。
示例
SQL
SELECT age, count(*) AS cnt FROM company GROUP BY age;