#1.刪除t_discredit_company_info表重複資料(t_discredit_company_info表資料重複)

DELETE FROM t_discredit_company_info WHERE id IN (

SELECT * FROM (

SELECT id FROM t_discredit_company_info WHERE (company_id,attribute_year_month)

IN ( SELECT company_id,attribute_year_month FROM t_discredit_company_info GROUP BY company_id,attribute_year_month HAVING COUNT(1) > 1

) AND id NOT IN (

-- 查詢最小id的記錄

SELECT MIN(id) FROM t_discredit_company_info GROUP BY company_id,attribute_year_month HAVING COUNT(1) > 1

)) AS stu_repeat_copy );
 

#2.查詢t_discredit_company表比t_discredit_company_info表多了哪些資料(t_discredit_company表資料多，t_discredit_company_info表資料少)

SELECT count(*) FROM t_discredit_company o LEFT JOIN t_discredit_company_info w ON o.company_id=w.company_id

WHERE w.company_id IS NULL;

#3.刪除t_discredit_company表的多餘資料(t_discredit_company表資料多，t_discredit_company_info表資料少)

delete from t_discredit_company where t_discredit_company.company_id not in

(select company_id from t_discredit_company_info);