当列不正确匹配时，SQL查询如何从多个表返回数据

Question

I've tried to find relevants informations but seems I can't figure this one by myself so I need assistance :)

For exemple, Table1 :

+-------+-------------+------+-----------+----------+
| ID    | SNA_Name    | Desc | Time      | Task_ID  |
+-------+-------------+------+-----------+----------+
| 741   | Temp        | NNE  | 2015-01-. | 1661     |
+-------+-------------+------+-----------+----------+

Table 2 :

+-------+-------------+
| ID    | Name        |
+-------+-------------+
| 741   | GRFDSD14    |
+-------+-------------+

Table 3 :

+-------+-------------+------+-----------+-------------------------+
| xx    | USER        | xx   | xx        | Data                    |
+-------+-------------+------+-----------+-------------------------+
| xx    | Mylsef      | xx   | xx        | xxx.dd.1661 azerty      |
+-------+-------------+------+-----------+-------------------------+

I would like to have something like this at the end :

(----------TABLE 1----------------------)(--Table 2---)(---TABLE 3---) 
+-------+-------------+------+-----------+-------------+-------------+
| ID    | SNA_Name    | Desc | Time      | Name        | USER        |
+-------+-------------+------+-----------+-------------+-------------+
| 741   | Temp        | NNE  |  2015-01-.| GRFDSD14    | Mylsef      |
+-------+-------------+------+-----------+-------------+-------------+

So far i've tried to match TABLE 1 and 2 like this using the same ID 741

SELECT a.ID, a.SNA_Name, a.Desc, a.Time, b.Name
FROM Table1 a
INNER JOIN Table2 b
on a.ID = b.ID

RESULT :

+-------+-------------+------+-----------+-------------+
| ID    | SNA_Name    | Desc | Time      | Name        |
+-------+-------------+------+-----------+-------------+
| 741   | Temp        | NNE  |  2015-01-.| GRFDSD14    |
+-------+-------------+------+-----------+-------------+

But to join the third Table I need to match with the Task_ID information : 1661 In the third Table, my ID is surrender by numbers so I can't use the symbol = And I want to print the Column USER in the same row where Data match with Task_ID

Thanks a lot.

[Edit -> Using SQL 2008

Answer 1

Try this for the join:

FROM Table1 
JOIN Table3 ON Table3.Data LIKE '%'+ CAST(Table1.Task_ID AS varchar(20)) + '%'

Answer 2

You don't mention what database you are using, so I can't give specifics, but I would try to create a calculated column using a regular expression that is able to compare for any of the situations you describe, thosae being...

sometimes the number has a period before it, sometimes it has a space before it, sometimes it has an apostrophe before it.

In the example below, the regular expression will check for any combination of the id with any of the above characters preceding it, and it also prevents mismatching from partial values - ie it will not match 56 and 4564.

SELECT
    *
FROM
   t1
LEFT JOIN 
    t2
ON 
    concat(t2.data, ' ') REGEXP concat('[\'. ]', t1.i2, ' ')

Some notes on the above - I concat a space onto the data column so that I always am guaranteed to have either the number followed by a space, or the number followed by some other text (like your "azerty"). I concat a space on the end of the id so that it will prevent matches where the same id is embedded in another value.

I hope this is helpful for someone.