A . update table A setcol2=’N’ where col1=1
B . modify table A setcol2=N where col1=1
C . update A set col2=’N’ where col1=1
D . modify A set col2=N where col1=1
[单选题]对于表A(col1 int,col2 char(1)),表B(col1 int,col2char(1)),为确保表A的数据全部被保留,下面正确的联接方式是()A . A inner join BB . A left join BC . A right join BD . Across join B
[单选题]A.lport综合征的基因突变不包括A.NPHS1B.COL4A3C.COL4A4D.COL4A5E.编码Ⅳ型胶原A链的基因突变
[名词解释] 龈谷gingival col