I am able to find the first 3 characters of a name using Substring and getting an output of what they are in a column by using the range between 1, 3. However I am unsure of getting the formal of:
Name | Count
-------------
Jan | 5
Feb | 3
My current code is:
SELECT SUBSTRING(Name, 1, 3)
From Table
Which is giving me the necessary output, should I be using a HAVING Clause involving COUNT?
Kind Regards.
Just add a COUNT(*)... GROUP BY like this:
SELECT SUBSTRING(Name, 1, 3), COUNT(*)
FROM Table
GROUP BY SUBSTRING(Name, 1, 3)
Related
I am working with Codeigniter and its Query Builder class where I have a table with IDs and names.
Those names look like 1234_1a or 2345_2a where 1a can be 1b or 2a,2b,3a... and so on.
Now I want to count all these "1234" and "2345" but write them as one type.
So far I tried with:
$this->db->like('names', '1a', 'before');
$this->db->or_like('names', '1b', 'before');
return $this->db->count_all_results('table');
But the problem:
What if there is 3456_2a but no 3456_1a, than it doesn't work anymore...
id name
2 1212_1a
3 1243_1a
7 3142_1a
24 1243_2a
30 3142_2b
80 2315_2b
136 1243_3b
512 8562_1a
This is how I would like it:
Result:
name count
1212 1
1243 1
3142 1
2315 1
8562 1
If we always want to return a count value of 1, when the count of the number of rows in more than 1 ... then we aren't really returning a count.
And what is the pattern of the names... do they end with a digit and a letter, or is that underscore character important too?
What is to be done with name values such as 12345a or 5678_b2 or 11_22_3b? How are those to be handled?
Seems to me like we want to use a SQL query like this:
SELECT SUBSTRING_INDEX(t.name,'_',1) AS `foo`
, 1 AS `count`
FROM (
SELECT 2 AS `id`, '1212_1a' AS `name`
UNION ALL SELECT 3, '1243_1a'
UNION ALL SELECT 7, '3142_1a'
UNION ALL SELECT 24, '1243_2a'
UNION ALL SELECT 30, '3142_2b'
UNION ALL SELECT 80, '2315_2b'
UNION ALL SELECT 136, '1243_3b'
UNION ALL SELECT 512, '8562_1a'
) t
GROUP BY `foo`
ORDER BY `foo`
The inline view (derived table) is in the query for testing. Replace that with the table reference:
SELECT SUBSTRING_INDEX(t.name,'_',1) AS `foo`
, 1 AS `count`
FROM mytable t
GROUP BY `foo`
ORDER BY `foo`
The expression for foo may need to be adjusted, to get desirable behavior with values that don't follow the regular pattern. Consider name values with no underscore, with more than one underscore, with endings other than a digit. We could also include a WHERE clause to exclude rows that don't follow the pattern,
WHERE t.name REGEXP '_[0-9][a-z]$'
(only name values that end with underscore, digit, lowercase letter).
Without a tested SQL query, I wouldn't know what to implement in CodeIgniter Query Builder.
I have the following mySQL table:
data
1
2
3
4
5
6
7
8
9
I would like to supply my select statement with two seperate lists
Exculde List:
1,4,5,7
Include List:
1,2,3,4,5,6,7
I tried the following statement:
Select * FROM table WHERE data NOT IN ('1,4,5,7') AND data IN ('1,2,3,4,5,6,7)
Expecting the following output:
data
2
3
6
But I received no results. I realize I passed an impossible condition but I don't know how to format my query to return the expected results.
Can anyone tell me what I'm doing wrong here?
IN takes a list of values, not a string that holds a delimited list of values.
Examples:
x IN (1, 2, 3)
x IN ('a', 'b', 'c')
Use IN (1,2,3) and not IN ('1,2,3') as the former compares to individual values 1, 2 and 3 while the latter is against the literal string 1,2,3.
Select * FROM ( (Select * FROM table WHERE data NOT IN ('1,4,5,7') ) AS table WHERE data IN ('1,2,3,4,5,6,7)
you try againt
I am stuck with the following issue. I have 1 table that looks like this:
field_number.. Value
````````````````````````````````
1 ......................... 1
2 ..........................1
3 ......................... 2
4 ..........................2
etc.
I want to group different fieldnumbers and have an average for the value column. So the output should be:
field_number................Value
name(1,2)...................... 1.............. ((1+1)/2)
name(3,4)...................... 2.............. ((2+2)/2)
I have checked previous questions but cannot find any question that covers this issue (I might search on the wrong keywords though). So if this has already been covered my appologies, but any help or a point to a previous answer would be appreciated.
** =============UPDATE============= **
I went through your suggestions but did not get it right. So I am trying to be more specific. I almost have the result I want apart from the fact I want to have a fixed value in one of my columns. I have the following query:
Select
Avg(wp_rg_lead_detail.value),
wp_rg_lead_detail.field_number,
From
wp_rg_lead_detail
Where
wp_rg_lead_detail.field_number In (15, 17, 24) A
UNION
Select
Avg(wp_rg_lead_detail.value),
wp_rg_lead_detail.field_number,
From
wp_rg_lead_detail
Where
wp_rg_lead_detail.field_number In (16, 108, 18)
etc.
This gives me a table with two columns
wp_rg_lead_detail.value................field_number
4.3 (average)..............................15 (first value of av calculation)
What I want is to change the field number (15 in this case) in a fixed value (text). What and how should I add this to the query?
SELECT avg(value) FROM table WHERE field_number in (1,2)
SELECT avg(value) FROM table WHERE field_number in (3,4)
If your table is really this simple, you can also get away with:
select distinct
Value,
count(Value) as '#'
from table_name
group by Value
If you acctually want to group by a range, than you can put the logic of the range in your grouping clause (see this fiddle)
select distinct
avg(Value) as average,
floor(Value),
count(Value) as '#'
from table_name
group by floor(Value)
In the fiddle I used grouping on whole integers, but you can make that as complex as you like (see, for instance, this example)
If you are actually also interested in your corresponding fields, use group_concat() like so
select
Value,
group_concat(
distinct field_number
order by Value
) as fields
from table_name tn1
group by Value
order by Value
output:
Value | fields
---------------------------------
1 | 1,2
2 | 3,4
See this fiddle implemented from this blog post
For a generalized answer.
SELECT CONCAT('name','(',GROUP_CONCAT(field_number),')') AS field_number,
AVG(Value) as Value
FROM table_name
group by table_name.`Value`
Hope this helps.
I want to achieve one thing though I'm not sure if it's possible.
So let's say I have a table with few columns, but only two of them are of interest to me right now. Example of table:
Column 1 | Column 2
blabla | blablahhhhh
wor154 | blablahhhhh
word123 | word12435564
something | some4565
What I want to achieve, is to select all fields where first 5 or more symbols of value of Column 2 don't match with first 5 or more symbols of value of Column 1. So I don't want to select rows where 5 or more symbols of value of Column 1 match 5 or more symbols of value of Column 2. In example, query should return only 2nd and 4th rows
So, is it possible and if it's, how it can be achieved. Thank you.
I'd go with a SUBSTRING():
SELECT col1 FROM table WHERE SUBSTRING(col1, 1, 5) <> SUBSTRING(col2, 1, 5);
You can use something similar to this:
select *
from table1
where substring(column1, 1, 5) != substring(column2, 1, 5)
See SQL Fiddle with Demo
I want to count string separators from a MySQL query, mean if the field value is
like :-
1,2,3,4,5
as the string is comma separated so the separator count will be 4.
any idea then please share
THANKS,
you can try to count the length of string and minus the length of string without commas as follows:
LENGTH('1,2,3,4,5') - LENGTH(REPLACE('1,2,3,4,5', ',', ''))
select length('1,2,3,4,5') - length(replace('1,2,3,4,5', ',', ''))
I suggest the following design :
Table name : USER_HOBBIES
| USER_ID | HOBBY_ID |
1 1
1 2
1 3
2 2
2 4
2 5
And now you can easily count user hobbies for a given user :
SELECT count(*) FROM USER_HOBBIES WHERE USER_ID = <user-id>
although it requires another table it is much clearer and on a long list of hobbies this will be much faster than using a function for manipulating strings.