Question: I don't know what this is called, but it is something like syncing android application and a Web server. Examples are RSS Feeds and Weather Forecast

Does anyone know the concept behind developing application? I mean how do you sync the Android phone with a web server. Is there any programming needed in the server side and the client side(Android)

Are there any programming books that tackles this subject? Thanks.

Answer: 
Well, yes, but it would be very slow and resource-intensive ... 

```
SELECT 
    myCol 
FROM 
    myTable 
WHERE 
    CHAR_LENGTH(myCol) = 3 
    AND SUBSTRING(myCol, 1, 1) IN ('1', '2', '3', '4', '5', '6', '7', '8', '9', '0') 
    AND SUBSTRING(myCol, 2, 1) IN ('1', '2', '3', '4', '5', '6', '7', '8', '9', '0') 
    AND SUBSTRING(myCol, 3, 1) IN ('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'W', 'X', 'Y', 'Z')

```

That'll match "12X" and "34Y" but not "123X" or "34YY".
You can test the first two digits using LIKE, and for the third use an ascii range. The first two digits can use an ascii range too, but LIKE should be better.

```
select *
from tbl
where length(n) = 3
  and '0123456789' like concat('%',mid(numcol,1,1),'%')
  and '0123456789' like concat('%',mid(numcol,2,1),'%')
  and ASCII(upper(MID(numcol,3,1))) between 65 and 90

```