How can i show dynamic row data into dynamic column - mysql

Hi all i have one table which have two colums i want to show column 2 data in different column nothing is fix every thing is dynamic like column creation based on rows
table 1
id col1 col2
1 x aa
2 x bb
3 x cc
4 y ww
5 y ee
6 z hh
7 z tt
8 z uu
9 z pp
10 z oo
i want table1 data in this format
id val1 val2 val3 val4 val5 val6
1 x aa bb cc null null
2 y ww ee null null null
3 z hh tt uu pp oo
can any one please help me out
how can i do this in mysql

this result:
| ID | VAL1 | VAL2 | VAL3 | VAL4 | VAL5 | VAL6 |
|----|------|------|------|--------|--------|--------|
| 1 | x | aa | bb | cc | (null) | (null) |
| 4 | y | ww | ee | (null) | (null) | (null) |
| 6 | z | hh | tt | uu | pp | oo |
from this query:
SELECT
MIN(id) AS id
, col1 AS val1
, MAX(CASE WHEN colno = 1 THEN col2 END) AS val2
, MAX(CASE WHEN colno = 2 THEN col2 END) AS val3
, MAX(CASE WHEN colno = 3 THEN col2 END) AS val4
, MAX(CASE WHEN colno = 4 THEN col2 END) AS val5
, MAX(CASE WHEN colno = 5 THEN col2 END) AS val6
FROM (
SELECT
#row_num :=IF(#prev_value = t.col1, #row_num + 1,1) AS colno
, t.id
, t.col1
, t.col2
, #prev_value := t.col1 as pv
FROM Table1 t
CROSS JOIN(SELECT #row_num := 1 x, #prev_value :='' y) vars
ORDER BY t.col1, t.id ASC
) sq
GROUP BY
col1
ORDER BY
col1
;
But you should note that sites such as this are not places where we just cough up finished work for you for nothing. You are supposed to demonstrate what you have tried at the very least. Claiming urgency isn't helpful, those who provide answers also have work to do and this is entirely voluntary.
Please prepare your next question with some evidence of research and an attempted query.

Related

Use CASE THEN in SQL

I have three tables which I want to query in MySQL as follows:
Table Notes
id | note
-------------------
1 | note 1
2 | note 2
Table Indices
id | name
-----------
1 | height
2 | weight
3 | other
Table Detail
note_id | indices_id | value
-------------------------------------
1 | 1 | 50
1 | 2 | 60
1 | 3 | 20
2 | 1 | 40
2 | 2 | 10
2 | 3 | 50
I need to query the result as follows:
indices.name | note_id = 1 | note_id = 2
------------------------------------------------
height | 50 | 40
weight | 60 | 10
other | 20 | 50
I tried this query:
SELECT i.name,
(CASE WHEN d.note_id = 1 THEN d.value END) as Col2,
(CASE WHEN d.note_id = 2 THEN d.value END) as Col3
FROM notes n,indices i,detail d
WHERE n.id = d.note_id AND i.id = d.indices_id
GROUP BY i.name
But Column Col3 result is null
Any help much appreciated! Thanks very much!
You need to use an aggregation function so that you don't get random row data on Col2 and Col3. MAX will work as it will ignore NULL values when the note_id doesn't match. Also, you should use explicit JOIN syntax:
SELECT i.name,
MAX(CASE WHEN d.note_id = 1 THEN d.value END) as Col2,
MAX(CASE WHEN d.note_id = 2 THEN d.value END) as Col3
FROM notes n
JOIN detail d ON n.id = d.note_id
JOIN indices i ON i.id = d.indices_id
GROUP BY i.name
Output:
name Col2 Col3
height 50 40
other 20 50
weight 60 10
Demo on dbfiddle
This is a variation of Nick's answer. The JOIN to nodes is superfluous:
SELECT i.name,
MAX(CASE WHEN d.note_id = 1 THEN d.value END) as Col2,
MAX(CASE WHEN d.note_id = 2 THEN d.value END) as Col3
FROM detail d JOIN
indices i
ON i.id = d.indices_id
GROUP BY i.name

Sum of repeating values in successive rows

I have a table like this:
id col1 col2 col3
10 1 3
9 1 2 3
8 2 3
7 2 3
6 1 2
5 3
Each column has one value only or null. Eg. Col1 has 1 or empty. Col2 has 2 or empty.
I'd like to get the sum of repeating values only between two successive rows.
so the result would look like this:
I need to get the sum of total repeating values in each row.
id col1 col2 col3 Count
10 1 3 2 (shows the repeating values between id10 & id9 rows)
9 1 2 3 2 (shows the repeating values between id9 & id8 rows)
8 2 3 1
7 2 1
6 1 2 0
5 3
I googled and tried some queries I found on the web but couldn't get the right result. Thanks in advance for your help.
To further clarify, for example:
id10 row has (1,,3) and id9 row has (1,2,3). so there is two values repeating. so count is 2.
If the ids are consecutive and there are no gaps, you can do it with a self join:
select
t.*,
coalesce((t.col1 = tt.col1), 0) +
coalesce((t.col2 = tt.col2), 0) +
coalesce((t.col3 = tt.col3), 0) count
from tablename t left join tablename tt
on tt.id = t.id - 1
See the demo.
Results:
| id | col1 | col2 | col3 | count |
| --- | ---- | ---- | ---- | ----- |
| 10 | 1 | | 3 | 2 |
| 9 | 1 | 2 | 3 | 2 |
| 8 | | 2 | 3 | 1 |
| 7 | | 2 | | 1 |
| 6 | 1 | 2 | | 0 |
| 5 | | | 3 | 0 |
And if there are gaps...
SELECT a.id
, a.col1
, a.col2
, a.col3
, COALESCE(a.col1 = b.col1,0) + COALESCE(a.col2 = b.col2,0) + COALESCE(a.col3 = b.col3,0) n
FROM
( SELECT x.*
, MIN(y.id) y_id
FROM my_table x
JOIN my_table y
ON y.id > x.id
GROUP
BY x.id
) a
LEFT
JOIN my_table b
ON b.id = a.y_id;
Were you to restructure your schema, then you could do something like this instead...
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id INT NOT NULL
,val INT NOT NULL
,PRIMARY KEY(id,val)
);
INSERT INTO my_table VALUES
(10,1),
(10,3),
( 9,1),
( 9,2),
( 9,3),
( 8,2),
( 8,3),
( 7,2),
( 7,3),
( 6,1),
( 6,2),
( 5,3);
SELECT a.id
, COUNT(b.id) total
FROM
( SELECT x.*
, MIN(y.id) next
FROM my_table x
JOIN my_table y
ON y.id > x.id
GROUP
BY x.id
, x.val
) a
LEFT
JOIN my_table b
ON b.id = a.next
AND b.val = a.val
GROUP
BY a.id;
+----+-------+
| id | total |
+----+-------+
| 5 | 0 |
| 6 | 1 |
| 7 | 2 |
| 8 | 2 |
| 9 | 2 |
+----+-------+
You can use :
select t1_ID, t1_col1,t1_col2,t1_col3, count
from
(
select t1.id as t1_ID, t1.col1 as t1_col1,t1.col2 as t1_col2,t1.col3 as t1_col3, t2.*,
case when t1.col1 = t2.col1 then 1 else 0 end +
case when t1.col2 = t2.col2 then 1 else 0 end +
case when t1.col3 = t2.col3 then 1 else 0 end as count
from tab t1
left join tab t2
on t1.id = t2.id + 1
order by t1.id
) t3
order by t1_ID desc;
Demo
If there are gaps between id values for the next row, you could have user defined variables to explicitly assign values to rows in their natural ordering in the table. Rest logic remains the same as already answered. You would do an inner join between current row number and next row number to get the col1,col2 and col3 values and use coalesce for computation of count.
select derived_1.*,
coalesce((derived_1.col1 = derived_2.col1), 0) +
coalesce((derived_1.col2 = derived_2.col2), 0) +
coalesce((derived_1.col3 = derived_2.col3), 0) count
from (
select #row := #row + 1 as row_number,t1.*
from tablename t1,(select #row := 0) d1
) derived_1
left join (
select *
from (
select #row2 := #row2 + 1 as row_number,t2.*
from tablename t2,(select #row2 := 0) d2
) d3
) derived_2
on derived_1.row_number + 1 = derived_2.row_number;
Demo: https://www.db-fiddle.com/f/wAzb67zSEfbZKg5RywQvC8/1

how to count how many times a number is repeated and more than one column

example::
JOHN | 1 | 6 | 2
PETER | 1 | 7 | 6
MARK | 2 | 1 | 6
DIANNA | 3 | 2 | 1
SPIDERMAN | 4 | 1 | 6
JAMIE FOXX | 5 | 1 | 6
how can I do a select count how many times that the numbers are repeated in each of the 3 columns
Example:
number 1 is repeated 6 times.
the number 6 is repeated 5 times.
Assuming your number column are c1,c2 and c3 and the table is t.
select c,count(*)
from ( select c1 as c from t
union all select c2 from t
union all select c3 from t
) t
group by c
;
Assuming you are looking for 1
A way is using union and sum
select sum(num) from
(
select count(*) as num
from my_table
where col1 = 1
union all
select count(*)
from my_table
where col2 = 1
union all
select count(*)
from my_table
where col3 = 1
) t
SELECT COUNT(CASE WHEN col1 = #number THEN 1 END) +
COUNT(CASE WHEN col2 = #number THEN 1 END) +
COUNT(CASE WHEN col3 = #number THEN 1 END) as repeat
FROM YourTable, (SELECT #number := 1) as parameter

SQL Aggregation with SUM, GROUP BY and JOIN (many-to-many)

Here's an example Table layout:
TABLE_A: TABLE_B: TABLE_A_B:
id | a | b | c id | name a_id | b_id
--------------------- --------- -----------
1 | true | X | A 1 | A 1 | 1
2 | true | Z | null 2 | B 1 | 2
3 | false | X | null 3 | C 2 | 2
4 | true | Y | Q 4 | 1
5 | false | null | null 4 | 2
5 | 1
Possible Values:
TABLE_A.a: true, false
TABLE_A.b: X, Y, Z
TABLE_A.c: A, B, C, ... basically arbitrary
TABLE_B.name: A, B, C, ... basically arbitrary
What I want to achieve:
SELECT all rows from TABLE_A
SUM(where a = true),
SUM(where a = false),
SUM(where b = 'X'),
SUM(where b = 'Y'),
SUM(where b = 'Z'),
SUM(where b IS NULL),
and also get the SUMs for all distinct TABLE_A.c values.
and also get the SUMs for all those TABLE_A_B relations.
The result for the example Table above should look like:
aTrue | aFalse | bX | bY | bZ | bNull | cA | cQ | cNull | nameA | nameB | nameC
-------------------------------------------------------------------------------
3 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 3 | 3 | 3 | 0
What I've done so far:
SELECT
SUM(CASE WHEN a = true THEN 1 ELSE 0 END) AS aTrue,
SUM(CASE WHEN b = false THEN 1 ELSE 0 END) AS aFalse,
SUM(CASE WHEN b = 'X' THEN 1 ELSE 0 END) AS bX,
...
FROM TABLE_A
What's my problem?
Selecting column TABLE_A.a and TABLE_A.b is easy, because there's a fixed number of possible values.
But I can't figure out how to count the distinct values of TABLE_A.c. And basically the same problem for the JOINed TABLE_B, because the number of values within TABLE_B is unknown and can change over time.
Thanks for your help! :)
EDIT1: New (preferred) SQL result structure:
column | value | sum
----------------------------
TABLE_A.a | true | 3
TABLE_A.a | false | 2
TABLE_A.b | X | 2
TABLE_A.b | Y | 1
TABLE_A.b | Z | 1
TABLE_A.b | null | 1
TABLE_A.c | A | 1
TABLE_A.c | Q | 1
TABLE_A.c | null | 3
TABLE_B.name | A | 3
TABLE_B.name | B | 3
TABLE_B.name | C | 0
From your original request of rows as a simulated pivot. By doing a SUM( logical condition ) basically returns 1 if true, 0 if false. So, since the column "a" is true or false, simple sum of "a" or NOT "a" (for the false counts -- NOT FALSE = TRUE). Similarly, your "b" column, so b='X' = true counted as 1, else 0.
In other sql engines, you might see it as SUM( case/when ).
Now, since your table counts don't rely on each other, they can be separate SUM() into their own sub-alias query references (pqA and pqB for pre-queryA and pre-queryB respectively). Since no group by, they will each result in a single row. With no join will create a Cartesian, but since 1:1 ratio, will only return a single record of all columns you want.
SELECT
pqA.*, pqB.*
from
( SELECT
SUM( ta.a ) aTrue,
SUM( NOT ta.a ) aFalse,
SUM( ta.b = 'X' ) bX,
SUM( ta.b = 'Y' ) bY,
SUM( ta.b = 'Z' ) bZ,
SUM( ta.b is null ) bNULL,
SUM( ta.c = 'A' ) cA,
SUM( ta.c = 'Q' ) cQ,
SUM( ta.c is null ) cNULL,
COUNT( distinct ta.c ) DistC
from
table_a ta ) pqA,
( SELECT
SUM( b.Name = 'A' ) nameA,
SUM( b.Name = 'B' ) nameB,
SUM( b.Name = 'C' ) nameC
from
table_a_b t_ab
join table_b b
ON t_ab.b_id = b.id ) pqB
This option gives your second (preferred) output
SELECT
MAX( 'TABLE_A.a ' ) as Basis,
CASE when a then 'true' else 'false' end Value,
COUNT(*) finalCnt
from
TABLE_A
group by
a
UNION ALL
SELECT
MAX( 'TABLE_A.b ' ) as Basis,
b Value,
COUNT(*) finalCnt
from
TABLE_A
group by
b
UNION ALL
SELECT
MAX( 'TABLE_A.c ' ) as Basis,
c Value,
COUNT(*) finalCnt
from
TABLE_A
group by
c
UNION ALL
SELECT
MAX( 'TABLE_B.name ' ) as Basis,
b.Name Value,
COUNT(*) finalCnt
from
table_a_b t_ab
join table_b b
ON t_ab.b_id = b.id
group by
b.Name
I think You will need to build dynamic query as you don't know possible values for column C in table A. So you can write store procedure where you can get list of distinct value for Column C in one variable and by using "Do WHILE" you can construct your dynamic query.
Please let me know if you need more help in detail
Dynamic SQL

mysql selecting a union where values in one don't appear in the other

sorry for the poorly titled post.
Say I have the following table:
C1 | C2 | c3
1 | foo | x
2 | bar | y
2 | blaz | z
3 | something| y
3 | hello | z
3 | doctor | x
4 | name | y
5 | continue | x
5 | yesterday| z
6 | tomorrow | y
I'm trying to come up w/ a sql statement which performs the following union:
1st retrieval retrieves all records w/ c3 = 'y'
2nd retrieval retrieves the first instance of a record where c3 <> 'y' and the result is not in the previous union
So, for the result, I should see:
C1 | C2
1 | foo
2 | bar
3 | something
4 | name
5 | continue
6 | tomorrow
So two questions: 1: Am I totally smoking crack where I think I can do this, and 2: (assuming I can), how do I do this?
Try this one:
SELECT a.C1, a.C2
FROM MyTable a
WHERE a.C3 = 'y'
UNION
SELECT b.C1, b.C2
FROM MyTable b
WHERE b.C3 <> 'y' AND
b.C1 not in
(
SELECT c.C1
FROM MyTable c
WHERE c.C3 = 'y'
)
UPDATE 1
by the way, why is that there is only one record of 5 in your desired result? where, in fact, there could be two.
SEE FOR DEMO 1
OR
SELECT g.C1, MIN(g.C2) C2
FROM
(SELECT a.C1, a.C2
FROM MyTable a
WHERE a.C3 = 'y'
UNION
SELECT b.C1, b.C2
FROM MyTable b
WHERE b.C3 <> 'y' AND
b.C1 not in
(
SELECT c.C1
FROM MyTable c
WHERE c.C3 = 'y'
)
) g
GROUP BY g.C1
SEE FOR DEMO 2 (yields same result with your desired result)
DEMO # Sql Fiddle.
select *
from table1
where c3 = 'y'
union all
(select table1.*
from table1
left join table1 t1
on table1.c1 = t1.c1
and t1.c3 = 'y'
where table1.c3 <> 'y'
and t1.c1 is null
-- The meaning of first becomes clear here
order by table1.c3, table1.c2
limit 1)
Note: foo is not in a list because it is marked as x.
Try this:
SELECT C1, C2
FROM Table1
Where C3 = 'y'
UNION
(
SELECT C1, C2
FROM Table1
Where C3 <> 'y' ORDER BY C1 LIMIT 1
)
ORDER BY C1