包含下级的SQL语句请教?(20分)

id &nbsp; mc &nbsp; &nbsp; &nbsp; prvid(0为一级)<br>1 &nbsp; &nbsp;内科 &nbsp; &nbsp; &nbsp; &nbsp; 0<br>2 &nbsp; &nbsp;外科 &nbsp; &nbsp; &nbsp; &nbsp; 0<br>3 &nbsp; &nbsp;内一科 &nbsp; &nbsp; &nbsp; 1<br>4 &nbsp; &nbsp;外一科 &nbsp; &nbsp; &nbsp; 2<br>5 &nbsp; &nbsp;内二科 &nbsp; &nbsp; &nbsp; 1<br>6 &nbsp; &nbsp;内一科（门） 3<br>.......<br>要求通过SQL语句求出已知的上级科室名称，求它的所有下级及名称.<br>如内科及内科下面的所有分级的名称<br>要求的结果如下：<br>id &nbsp; &nbsp;mc &nbsp; &nbsp; <br>1 &nbsp; &nbsp; 内科 &nbsp;<br>3 &nbsp; &nbsp; 内一科<br>5 &nbsp; &nbsp; 内二科<br>6 &nbsp; &nbsp; 内一科(门)

select id ,mc from table where mc like '内%'

Select * From Table Where Prvid In(<br>&nbsp; Select Prvid From Table Where mc=''<br>)

Select * From Table Where Prvid In(<br>&nbsp; Select id From Table Where mc=''<br>)

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