1、根据单行判断重复
(1)查找重复项
SELECT * FROM graph_disease_corresponding WHERE diag_pingan IN ( SELECT diag_pingan FROM `graph_disease_corresponding` GROUP BY diag_pingan HAVING COUNT(diag_pingan) > 1 )
(2)删除重复项(根据多列进行删除且保留ID最小的一条)
DELETE FROM graph_disease_corresponding WHERE diag_pingan IN ( SELECT diag_pingan FROM ( SELECT diag_pingan FROM `graph_disease_corresponding` GROUP BY diag_pingan HAVING COUNT(diag_pingan) > 1 ) a ) AND id NOT IN ( SELECT * FROM ( SELECT MIN(id) FROM graph_disease_corresponding GROUP BY diag_pingan HAVING COUNT(diag_pingan) > 1 ) b );