我需要计算在 study_date 之前的 12 个月内哪些人有哮喘疾病代码。 Study_date 因人而异,因此我无法使用实际日期。我正在使用如下 WHERE 子句:
XXXX (code for main query)
WHERE disease_code = "asthma"
AND (disease_date BETWEEN (study_date - 12 months) AND study_date)
如何对“study_date - 12 months”部分进行编码?
非常感谢
在MySQL中,必须使用INTERVAL
SELECT * FROM tab1 WHERE disease_code = "asthma"
AND (disease_date BETWEEN (study_date - INTERVAL 12 month) AND study_date)
IBM DB2
SELECT * FROM tab1 WHERE disease_code = "asthma"
AND (disease_date BETWEEN study_date - 12 MONTHS AND study_date)