How do I transform table- see example?
If someone suggests a better question title, I will change it, but that's the best I could come up with.
I am using SQL Server 2005
Is there a good way to transform table 'table_1' to 'table_2' using SQL.
Edit: I don't necessarily want to create a new table, I just want to represent it in a query as so that it will look like 'table_2'
table_1:
a b
1 TRUE
2 FALSE
4 TRUE
7 FALSE
9 TRUE
10 FALSE 开发者_运维百科
table_2:
x y z
1 2 TRUE
2 4 FALSE
4 7 TRUE
7 9 FALSE
9 10 TRUE
The reason I want to do this is so that if I have table_3:
table_3:
id m
a 3
b 4
c 8
I would like to query against table_2 (transformed table_1) like this:
SELECT table_3.id
FROM table_3
FROM table_2
WHERE m BETWEEN x AND y
AND z = TRUE
I'll answer the following questions a head of time: 1. I can not change the table design, nor did I design the table. 3. I have good reason not to process this on client side with c# or another language.
thanks
Try a self-join:
select t1.a, min(t2.a), t1.b
from table_1 t1
inner join table_1 t2 on t2.a > t1.a
group by t1.a, t1.b
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