balances username varchar(255) NOT NULL, balanceCONSTRAINT balances_pkey PRIMARY KEY (username, currency)在尝试之后 INSERT INTO balances(username, currency, to_add)
ON CON
假设在运行查询之前fees_balance为10000,则以下查询返回17000:fees_balance=T2.fees_balance + 7000tbl_classes T2 WHERE CAST(tbl_classes.mobile_number AS TEXT)
LIKE '%71000001' RETURNING tbl_classes.fees_balance