各位高手帮我解决一个问题

[mfkvfn]

有两个表table1和table2, 结构都是这样：
LineNo | LineString
1 | adadafdasf
2 | fgfdgfdgfgfd
3 | dfsdfsdfs
... | ....
问我要如何生成一个表table3,结构是这样
LineNo1 | LineNo2 | LineString
1 1 adadafdasf
2 0 fgfdgfdgfgfd
3 2 dfsdfsdfs
0 3 bfdgdgs
... ... ...
其中LineNo1意义为：table1中对应的LineNo
LineNo2意义为：table2中对应的LineNo
LineString意义为：LineNo1或LineNo2对应的字符串
若LineNo2为0，意义为：table1中没有与之相同的字符串
若LineNo1为0，意义为：table2中没有与之相同的字符串
若LineNo1和LineNo2都不为0，意义为：table1和table2中有相同的字符串
不知有没有SQL语句可以使用，若有请各位高手告之。

[WorldMobile]

select line_no lineno1, 0 lineno2, linestring
from table1
where line_no not in (select line_no from table2)

union all

select 0 lineno1, line_no lineno2, linestring
from table2
where line_no not in (select line_no from table1)

即可
union all

select table1.line_no lineno1, table2.line_no lineno2, table1.linestring
from table1, table2
where table1.line_no = table2.line_no

[WorldMobile]

select line_no lineno1, 0 lineno2, linestring
from table1
where line_no not in (select line_no from table2)

union all

select 0 lineno1, line_no lineno2, linestring
from table2
where line_no not in (select line_no from table1)

union all

select table1.line_no lineno1, table2.line_no lineno2, table1.linestring
from table1, table2
where table1.line_no = table2.line_no

即可

[progrose]

select line_no lineno1, 0 lineno2, linestring
from table1
where linestring not in (select linestring from table2)

union all

select 0 lineno1, line_no lineno2, linestring
from table2
where linestring not in (select linestring from table1)

union all

select table1.line_no lineno1, table2.line_no lineno2, table1.linestring
from table1, table2
where table1.linestring = table2.linestring