PostgreSQL数据库如果不存在则插入，存在则更新

INSERT INTO UM_CUSTOMER(customercode,CompanyFlag,InputTime,LocalVersion)
VALUES('201801010001','0','2017-02-22 12:00:00',1)
ON conflict(customercode) 
DO UPDATE SET CompanyFlag = '1', InputTime ='2017-02-22 12:00:00',LocalVersion=1