postgresql - 如何让这个查询在 postgresql 上工作？

Question

有谁知道如何调整这个查询以便它在 postgresql 中工作？add_months 函数显然不存在。非常感谢！

WITH monthly_activity AS (SELECT date_trunc('month', "Date"::date) AS "month", "Company ID"
FROM "DWH_rollup".appointments_totals)

SELECT last_month."month" + add_months(last_month."month", 1), COUNT(DISTINCT last_month."Company ID")
FROM monthly_activity last_month
JOIN monthly_activity this_month
ON this_month."Company ID" = last_month."Company ID" 
AND this_month."month" = add_months(last_month."month", 1)
WHERE this_month."Company ID" is NULL
GROUP BY 1

标签： postgresqlpostgresql-9.3