i have a table like this with a var char field reference_number
actually i need to get the max of number in that field
<<student>>
|`id` | `reference_number`(varchar(25))
--------------------------
| 1 | L250
| 2 | SP521
| 3 | S120
| 4 | SP500
| 5 | S122
the desired result is 521 because if we are avoiding the non numeric value then it will come like this
|`id` | `reference_number`
--------------------------
| 1 | 250
| 2 | 521
| 3 | 120
| 4 | 500
| 5 | 122
how to get the the value 521 from the table
I assume you have extracted 'reference_number' as shown in the second snippet from the first snippet. if so, try :::
select max(cast (reference_number as int)) from student
In order to get the number 521 (and all the numbers from the reference_number column) you could try:
SELECT *
FROM yourtable
WHERE reference_number REGEXP '^[0-9]+$';
And then you can add an order by statement.
Related
Let me say i have a table called test with the following data
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 2 | 355488020906457 |
| 3 | 864296100098739 |
| 4 | 864296100098325 |
| 5 | 864296100119956 |
What i want to do is to be able to write a select statement that returns a 3 rows with two random values and one mandatory value from the t_number column
for example if the mandatory value is 864291100247345 the output should something like below
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 2 | 355488020906457 |
| 4 | 864296100098325 |
OR
+---------+-----------------+
| id | t_number |
+---------+-----------------+
| 1 | 864291100247345 |
| 3 | 864296100098739 |
| 4 | 864296100098325 |
I have tried the below query but it's not yielding the output i expect, in a sense that it does return a result but without the mandatory value
SELECT * FROM test WHERE t_number = 864291100247345 OR id LIMIT 3;
What is the best way to go about this?
Thank you.
You can use order by:
SELECT t.*
FROM test
ORDER BY (t_number = 864291100247345) DESC,
rand()
LIMIT 3;
This returns the mandatory number first and then random numbers after that.
MySQL treats boolean values (the result of the = expression) as numbers in a numeric context, with "1" for true and "0" for false. So the first expression in the order by sorts the result set with the "true" conditions first, followed by the others.
Here is my table:
| ID | NUMBER |
| 1 | 523 |
| 2 | 293 |
| 3 | 948 |
And now, I want to get all NUMBER values but I want to add in result two numbers - 48 - (without upadting existing results). So finally I want print these results:
| NUMBER |
| 48523 |
| 48293 |
| 48948 |
So I need a query, something like this:
SELECT '48' + `number` FROM `table`
but this query doesn't work fine (this query only update column name from NUMBER to 48 + NUMBER).
Any ideas?
Thanks.
You need CONCAT
SELECT CONCAT('48' , `number`) AS number FROM table
Demo
I have one table having 5 columns
linkid, orinodeno, orinodeno, ternodeno, terifindex
linkid is autoincremented. orinodeno, oriifindex is one combination value and ternodeno, terifindex other combination (orinodeno,oriifindex is originating value and ternodeno,terifindex terminating value i.e, in between there is a link eg just like map two pts n in between connecting link) so my table contains a->b values (i.e a is combination of orinodeno, oriifindex and b is combination of ternodeno,terifindex) and b->a values. so I have to select only a->b set of values not b->a. Also sending my table image. My Table
There is no a map definition in sql databases, forget it. Check any database normalization tutorial. Then you shouldn't have any problems with select statements.
Please be clear about what you are asking. If you can not explain in words, please give example input and your expected output.
From link of table image you have provided and description, It looks like you expect following:
Data in current table:
------------------------------------------------------------------
|linkid | orinodenumber | oriifindex | ternodenumber | terifindex|
------------------------------------------------------------------
|305 | 261 | 2 | 309 | 2 |
|306 | 309 | 2 | 261 | 2 |
|307 | 257 | 10 | 310 | 10 |
|308 | 310 | 10 | 257 | 10 |
|309 | 257 | 11 | 310 | 11 |
------------------------------------------------------------------
Expected Output:
------------------------------------------------------------------
|linkid | orinodenumber | oriifindex | ternodenumber | terifindex|
------------------------------------------------------------------
|305 | 261 | 2 | 309 | 2 |
|307 | 257 | 10 | 310 | 10 |
------------------------------------------------------------------
If that is your case, following query might help you (Assuming table name as link_table):
SELECT *
FROM link_table o
WHERE EXISTS (SELECT linkid
FROM link_table i
WHERE o.orinodenumber = i.ternodenumber
AND o.oriifindex = i.terifindex
AND o.linkid < i.linkid);
Suppose you have a table
id | title
-----------
1 | ali
2 | Ali
3 | alireza
Now I want you to say a command word "ali" check the field's title.
And the output of the table was a table that all records should be returned in the table.
Now the results should be like.
id | title | diff
---------------------
1 | ali | 100
2 | Ali | 97
3 | alireza | 50
Important: only use commands Sql
Here you go:
select id, title,
case title
when 'ali' then 100
when 'Ali' then 97
when 'alireza' then 50
end case diff
from mytable;
+----------+------------+
| name | code |
+----------+------------+
| Fluffy | 000 |
| Claws | 217 |
| Buffy | 598 |
| Fang | 000 |
| Bowser | 687 |
| Chirpy | 587 |
| Whistler | 258 |
| Slim | 298 |
| Fluffy | 168 |
+----------+------------+
Here's my problem... in the above table the default value for column "code" is 000.In the column "name", Fluffy has 2 code one is the default 000 & the other one 168 When selecting, if fluffy has something other than the default code i've to select that & other rows leaving out the one row with default for Fluffy.Any way to do that with mysql IF or any other ? Hope my question is clear.
Use max() to get the highest code. If there is only 000 then that will be returned.
select name, max(code) as code
from your_table
group by name
SELECT name,MAX(code) FROM myTABLE GROUP BY name
This will select the highest code for that person, assuming all your other codes will be positive numbers.
You can simply use MAX(code) for that:
SELECT name, MAX(code)
FROM yourTable
GROUP BY name