SQL表A更新和表B同步

CREATE DATABASE T

create table A
(
    ID int,
    UserName nvarchar(50)
)

create table B
(
    ID int,
    UserDisplayName nvarchar(50)
)

insert into A values(1,'USER1');
insert into A values(2,'USER2');
insert into A values(3,'USER3');

insert into B values(1,'Display1');
insert into B values(2,'Display2');
insert into B values(3,'Display3');
insert into B values(4,'Display4')

update A set A.UserName = B.UserDisplayName from A,B where A.ID = B.ID

效果如图所示：