I have this table
CREATE TABLE table1 (
`ID` VARCHAR(100),
`Val` VARCHAR(100),
`Val2` VARCHAR(100)
);
and this value
INSERT INTO table1
(`ID`, `Val`, `Val2`)
VALUES
('1','1234 ','now'), // 1 whitespace
('2','1234 ','now1'), // 2 whitespace
('5','1234 ','now190'), // 2 whitespace
('3','1234 ','now2'), // 3 whitespace
('4','3123123','now3')
I need to group by the data and count how many data that have same value, so i used group by and count
select Val,count(*) from `table1` group by Val
the result not what i expect because the data for ID 1,2,5, and 3 is counted as same value like below result
Val count(*)
1234 4
3123123 1
how could i make the result like expected result below so the value didn't count as same value
Val count(*)
1234 1 // 1 whitespace
1234 2 // 2 whitespace
1234 1 // 3 whitespace
3123123 1
see this fiddle for demo
This is just how MySQL does it by default, unless you use some specific collation. A typical workaround is to use binary:
select binary val, count(*) cnt from table1 group by binary val
Or, if you do want a regular string in the resultset rather than a binary string:
select max(val) as newval, count(*) cnt from table1 group by binary val
Related
SELECT asset_tag.asset_id, LEFT(asset_tag,SUBSTRING(asset_tag)-1 AS 'ETIQ'
from (SELECT DISTINCT S2.asset_id + ',' AS etiquetas
(SELECT S1.tag_id
FROM asset_tag AS S1
WHERE S1.tag_id
ORDER BY S1.tag_id
FOR XML PATH (''),TYPE
).VALUE('TEXT(1)`[1]','ninteger(MAX')[aset_tag] FROM asset_tag AS S2 ) asset_tag;
I have to group by asset and the asset 1 have in one column 1,2,3,4,5 or the tag that it have
how to use heidisql functions, on dbforge? I know but here not I use heidisql version 12. and is my first time working with this
The objective is that the source table that has two columns, group by column 1 and that a new column indicate separated by commas what column 1 has in column 2 (of origin).
columna 1 - 1 1 2 2 3 3 4 4
columna 2 - a b c a d a f g
and in a new column or table 1 - a b / 2 - b c
I see this answer on this page: https://stackoverflow.com/a/545672/20100117 But i don´t know what mean "st1" or [text()] the alias?
SELECT Main.SubjectID,
LEFT(Main.Students,Len(Main.Students)-1) As "Students" FROM
(
SELECT DISTINCT ST2.SubjectID,
(
SELECT ST1.StudentName + ',' AS [text()]
FROM dbo.Students ST1
WHERE ST1.SubjectID = ST2.SubjectID
ORDER BY ST1.SubjectID
FOR XML PATH (''), TYPE
).value('text()[1]','nvarchar(max)') [Students]
FROM dbo.Students ST2
) [Main]
If you use HeidiSQL, you can use the completion proposal to help finding the right syntax for the various functions. Just type some first characters and press Ctrl+Space:
Here's a basic example of how SUBSTRING() works:
SELECT SUBSTRING(name, 2, 3) FROM mytable;
How to concatenate rows of the same column in PostgreSQL?
Given that you want to concatenate rows of the same column, and not different columns (which is what you do when using CONCAT_WS()), what you would really be looking for is to use the ARRAY_AGG aggregation function within the ARRAY_TO_STRING function.
Documentation: https://www.postgresql.org/docs/13/functions-array.html
solution:
SELECT
a.asset_id, ARRAY_TO_STRING(ARRAY_AGG(a.tag_id), ',') AS etiqueta
FROM public.asset_tag AS a
GROUP BY a.asset_id;
Result:
on asset_id 1 | 1,3,5 tag_id
on asset_id 6 | 1,2 tag_id
If you insert this:
CREATE TABLE asset_tag ( asset_id INT,tag_id INT);
INSERT INTO asset_tag VALUES (1,1);
INSERT INTO asset_tag VALUES (1,3);
INSERT INTO asset_tag VALUES (1,5);
INSERT INTO asset_tag VALUES (6,1);
INSERT INTO asset_tag VALUES (6,2);
thanks to the person who gave me this answer .
I have a table with json values like this:
-Table 1
id | name | data
------+----------+---------------
1 | Test | {"city_id": 3, "email":"test#test.com", "city_name":"something"}
2 | Test 2 | {"city_id": 1, "email":"test2#test2.com", "city_name":"another"}
3 | Test 3 | {"city_id": 6, "email":"test3#test3.com", "city_name":"blahblah"}
Now I want SELECT records with order by data.city_name, so I use this code:
SELECT id, name, JSON_EXTRACT(data, 'city_name') AS cityName
FROM table1
ORDER BY cityName ASC
but this query cannot sort my records correctly !
P.S: city_name have UTF-8 characters.
you do not seem to be using JSON_EXTRACT() properly, try with:
SELECT id, name, JSON_EXTRACT(data, '$.city_name') AS cityName
FROM demo ORDER BY cityName ASC
Demo Fiddle
I usually cast the JSON value (->>) to the correct type in order to sort properly:
SELECT id, name, data->>'$.city_name' AS cityName
FROM table1
ORDER BY CAST(cityName AS CHAR) ASC
Otherwise, you end up sorting as a blob (binary), which are treated as binary strings (byte strings) and thus they have the binary character set and collation, and comparison and sorting are based on the numeric values of the bytes in column values (ref).
the easiest way in my opinion
SELECT * FROM YourTable order by data->"$.city_name" desc
Check This.
SELECT Id ,name,SUBSTRING_INDEX(SUBSTRING_INDEX(data,'city_name":"',-1),'"',1) as CITY
FROM tempjson
order by SUBSTRING_INDEX(SUBSTRING_INDEX(data,'city_name":"',-1),'"',1)
OutPut :
I have this query :
select
name
from
provinces
WHERE
province_id IN(1,3,2,1)
ORDER BY FIELD(province_id, 1,3,2,1)
the Number of values in IN() are dynamic
How can I get all rows even duplicates ( in this example -> 1 ) with given ORDER BY ?
the result should be like this :
name1
name3
name2
name1
plus I shouldn't use UNION ALL :
select * from provinces WHERE province_id=1
UNION ALL
select * from provinces WHERE province_id=3
UNION ALL
select * from provinces WHERE province_id=2
UNION ALL
select * from provinces WHERE province_id=1
You need a helper table here. On SQL Server that can be something like:
SELECT name
FROM (Values (1),(3),(2),(1)) As list (id) --< List of values to join to as a table
INNER JOIN provinces ON province_id = list.id
Update: In MySQL Split Comma Separated String Into Temp Table can be used to split string parameter into a helper table.
To get the same row more than once you need to join in another table. I suggest to create, only once(!), a helper table. This table will just contain a series of natural numbers (1, 2, 3, 4, ... etc). Such a table can be useful for many other purposes.
Here is the script to create it:
create table seq (num int);
insert into seq values (1),(2),(3),(4),(5),(6),(7),(8);
insert into seq select num+8 from seq;
insert into seq select num+16 from seq;
insert into seq select num+32 from seq;
insert into seq select num+64 from seq;
/* continue doubling the number of records until you feel you have enough */
For the task at hand it is not necessary to add many records, as you only need to make sure you never have more repetitions in your in condition than in the above seq table. I guess 128 will be good enough, but feel free to double the number of records a few times more.
Once you have the above, you can write queries like this:
select province_id,
name,
#pos := instr(#in2 := insert(#in2, #pos+1, 1, '#'),
concat(',',province_id,',')) ord
from (select #in := '0,1,2,3,1,0', #in2 := #in, #pos := 10000) init
inner join provinces
on find_in_set(province_id, #in)
inner join seq
on num <= length(replace(#in, concat(',',province_id,','),
concat(',+',province_id,',')))-length(#in)
order by ord asc
Output for the sample data and sample in list:
| province_id | name | ord |
|-------------|--------|-----|
| 1 | name 1 | 2 |
| 2 | name 2 | 4 |
| 3 | name 3 | 6 |
| 1 | name 1 | 8 |
SQL Fiddle
How it works
You need to put the list of values in the assignment to the variable #in. For it to work, every valid id must be wrapped between commas, so that is why there is a dummy zero at the start and the end.
By joining in the seq table the result set can grow. The number of records joined in from seq for a particular provinces record is equal to the number of occurrences of the corresponding province_id in the list #in.
There is no out-of-the-box function to count the number of such occurrences, so the expression at the right of num <= may look a bit complex. But it just adds a character for every match in #in and checks how much the length grows by that action. That growth is the number of occurrences.
In the select clause the position of the province_id in the #in list is returned and used to order the result set, so it corresponds to the order in the #in list. In fact, the position is taken with reference to #in2, which is a copy of #in, but is allowed to change:
While this #pos is being calculated, the number at the previous found #pos in #in2 is destroyed with a # character, so the same province_id cannot be found again at the same position.
Its unclear exactly what you are wanting, but here's why its not working the way you want. The IN keyword is shorthand for creating a statement like ....Where province_id = 1 OR province_id = 2 OR province_id = 3 OR province_id = 1. Since province_id = 1 is evaluated as true at the beginning of that statement, it doesn't matter that it is included again later, it is already true. This has no bearing on whether the result returns a duplicate.
I want count the length of a comma separated column
I have use these
(LENGTH(Col2) - LENGTH(REPLACE(Col2,",","")) + 1)
in my select query.
Demo:
id | mycolumn
1 2,5,8,60
2 4,5,1
3 5,Null,Null
query result for first two row is coming correctly.for 1 = 4 ,2 = 3 but for 3rd row it is calculating null value also.
Here is what I believe the actual state of your data is:
id | mycolumn
1 2,5,8,60
2 4,5,1
3 NULL
In other words, the entire value for mycolumn in your third record is NULL, likely from doing an operation involving a NULL value. If you actually had the text NULL your current query should still work.
The way to get around this would be to use COALESCE(val, "") when handling the NULL values in your strings.
Crude way of doing it is to replace the occurances of ',Null' with nothing first:-
SELECT a.id, (LENGTH(REPLACE(mycolumn, ',Null', '')) - LENGTH(REPLACE(REPLACE(mycolumn, ',Null', ''),",","")) + 1)
FROM some_table a
If the values refer to the id of rows in another table then you can join against that table using FIND_IN_SET and then count the matches (assuming that the string 'Null' is not an id on that other table)
SELECT a.id, COUNT(b.id)
FROM some_table a
INNER JOIN id_list_table b
ON FIND_IN_SET(b.id, a.mycolumn)
GROUP BY a.id
I am trying to compare two entries of 6 numbers, each number which can either can be zero or 1 (i.e 100001 or 011101). If 3 out of 6 match, I want the output to be .5. If 2 out of 6 match, i want the output to be .33 etc.
Note that position matters. A match only occurs when both entries have a 1 in the first position, both have a 0 in the second position etc.
Here are the SQL commands to create the table
CREATE TABLE sim
(sim_key int,
string int);
INSERT INTO sim (sim_key, string)
VALUES (1, 111000);
INSERT INTO sim (sim_key, string)
VALUES (2, 101101);
My desired output to compare the two strings, which share 50% of the characters, and output 50%.
Is it possible to do this sort of comparison in SQL? Thanks in advance
Have a look at this example.
CREATE TABLE sim (sim_key int, string int);
INSERT INTO sim (sim_key, string) VALUES (1, 111000);
INSERT INTO sim (sim_key, string) VALUES (2, 101101);
select a.string A, b.string B,
sum(case when Substring(A.string,Pos,1) = Substring(B.string,Pos,1) then 1 else 0 end) Matches,
count(*) as RowCount,
(sum(case when Substring(A.string,Pos,1) = Substring(B.string,Pos,1) then 1 else 0 end) /
count(*) * 100.0) as PercentMatch
from sim A
cross join sim B
inner join (
select 1 Pos union all select 2 union all select 3
union all select 4 union all select 5 union all select 6) P
on P.Pos between 1 and length(A.string)
where A.sim_key= 1 and B.sim_key = 2
group by a.string, b.string
It is crude and probably included more than required but shows how it can be done. It is better to create a numbers table with just numbers from 1 to 1000 or so, that can be used repeatedly in many queries where a number sequence is required. Such a table will replace the (select .. union virtual table used in the inner join)
Instead of keeping 10010101 as integer convert this binary version to true integer when compare use bit logic AND, result convert to binary and count '1' to how many match...
for convert: http://dev.mysql.com/doc/refman/5.5/en/binary-varbinary.html
for compare: http://dev.mysql.com/doc/refman/5.5/en/bit-functions.html bitwise AND
...