SQL整理八
结构表：TabTest+-------+--------+|t_Code t_Name ||1 a ||2 b ||11 c |+-------+--------+SQL：+-----------------------------------------------------------+Create table TabTest(t_Code varchar(10),t_Name varchar(10)); insert into TabTest values('1','a'); insert into TabTest values('2','b'); insert into TabTest values('11','c');+-----------------------------------------------------------+(代码11表示为1的下级)结果表:+--------+--------+--------+|代码 名称 有无下级 |+--------+--------+--------+| t_Code | t_name | you_wu |+--------+--------+--------+| 1 | a | you | | 2 | b | wu | | 11 | c | wu |+--------+--------+--------+要求：1.通过一条语句，得到结果表的数据。+---------------------------------------------+|select tt1.t_Code,tt1.t_name,( || case || when exists (select 1 from TabTest tt2 | | where tt2.t_code like CONCAT(tt1.t_code,'%')| | and tt2.t_code <> tt1.t_code ) || then 'you' || else 'wu' || end ||) as you_wu from TabTesttt1; |+---------------------------------------------+
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