I have a table that I need has multiple rows and I to put them all into a new table.
All my rows need to be converted into one row.
+-------+-----------+-------+--------+
| ID | Name | Last | Gender |
+-------+-----------+-------+--------+
| 1 | Person1 | Last1 | M |
| 2 | Person2 | Last2 | F |
| 3 | Person3 | Last3 | M |
| 4 | Person4 | Last4 | F |
+-------+-----------+-------+--------+
I need to convert the above table to the below:
+-------+------------+------------+
| NewID | ColumnName | Value |
+-------+------------+------------+
| 1 | ID | 1 |
| 1 | Name | Person1 |
| 1 | Last | Last1 |
| 1 | Gender | M |
| 2 | ID | 2 |
| 2 | Name | Person2 |
| 2 | Last | Last2 |
| 2 | Gender | F |
| 3 | ID | 3 |
| 3 | Name | Person3 |
| 3 | Last | Last3 |
| 3 | Gender | M |
| 4 | ID | 4 |
| 4 | Name | Person4 |
| 4 | Last | Last4 |
| 4 | Gender | F |
| | | |
+-------+------------+------------+
The most general method is to use union all:
select 'id' as columnname, cast(id as varchar(255)) as value from t union all
select 'name', name as value from t union all
select 'last', last as value from t union all
select 'gender', gender as value from t;
This should work in basically any database, although the cast to a string might vary. Some databases offer other solutions that are more efficient.
Union happy solution.
select 'id' as columnname, id as value from table
union all
select 'name' as columnname, name as value from table
union all
.e
.t
.c
Related
I have three table with below details:
Table 1: worklog
+-----------+------------+-------------+
| worklogid | technician | description |
+-----------+------------+-------------+
| 1 | john | some text |
+-----------+------------+-------------+
| 2 | jack | some text |
+-----------+------------+-------------+
| 3 | john | some text |
+-----------+------------+-------------+
| 4 | jenifer | some text |
+-----------+------------+-------------+
Table 2: task
+--------+-------+-------------+
| taskid | owner | description |
+--------+-------+-------------+
| 1 | john | some text |
+--------+-------+-------------+
| 2 | john | some text |
+--------+-------+-------------+
| 3 | john | some text |
+--------+-------+-------------+
| 4 | jack | some text |
+--------+-------+-------------+
Table 3: request
+-----------+------------+-----------+-------------+
| requestid | technician | title | description |
+-----------+------------+-----------+-------------+
| 1 | john | some text | ... |
+-----------+------------+-----------+-------------+
| 2 | sara | some text | ... |
+-----------+------------+-----------+-------------+
| 3 | john | some text | ... |
+-----------+------------+-----------+-------------+
| 4 | jack | some text | ... |
+-----------+------------+-----------+-------------+
Now I need to SQL query for this result:
+------------+------------------+---------------+------------------+
| technician | count(worklogid) | count(taskid) | count(requestid) |
+------------+------------------+---------------+------------------+
| john | 2 | 3 | 2 |
+------------+------------------+---------------+------------------+
| jack | 1 | 1 | 1 |
+------------+------------------+---------------+------------------+
| jenifer | 1 | 0 | 0 |
+------------+------------------+---------------+------------------+
| sara | 0 | 0 | 1 |
+------------+------------------+---------------+------------------+
What should I do?
One method is to just use union all and aggregation:
select techician, sum(is_workid), sum(is_taskid), sum(is_requestid)
from ((select technician, 1 as is_workid, 0 as is_taskid, 0 as is_requestid
from worklog
) union all
(select owner, 0, 1, 0
from task
) union all
(select technician, 0, 0, 1
from request
)
) t
group by technician;
In Postgres, you can also aggregate before joining:
select *
from (select technician, count(*) as num_workid
from worklog
group by technician
) w full join
(select owner as technician, count(*) as num_task
from task
group by owner
) t
using (technician) full join
(select technician, count(*) as num_request
from request
group by technician
) w
using (technician);
With a full join, I find that using is simpler than on clauses. But the name needs to be the same in all the tables.
the supply table:
supply_id | title | author | price | amount |
+-----------+----------------+------------------+--------+--------+
| 1 | Лирика | Пастернак Б.Л. | 518.99 | 2 |
| 2 | Черный человек | Есенин С.А. | 570.20 | 6 |
| 3 | Белая гвардия | Булгаков М.А. | 540.50 | 7 |
| 4 | Идиот | Достоевский Ф.М. | 360.80 | 3
I am trying to insert into book , all the values from supply:
+---------+-----------------------+------------------+--------+--------+
| book_id | title | author | price | amount |
+---------+-----------------------+------------------+--------+--------+
| 1 | Мастер и Маргарита | Булгаков М.А. | 670.99 | 3 |
| 2 | Белая гвардия | Булгаков М.А. | 540.50 | 5 |
| 3 | Идиот | Достоевский Ф.М. | 460.00 | 10 |
| 4 | Братья Карамазовы | Достоевский Ф.М. | 799.01 | 2 |
| 5 | Стихотворения и поэмы | Есенин С.А. | 650.00 | 15 |
+---------+-----------------------+------------------+--------+--------+
insert into book(title,author,price,amount)
select * from supply;
the primary ids conflict with each other - both tables start with id '1'
ERROR 1136: Column count doesn't match value count at row 1
Your columns in insert and select mismatches. You need to give explicit names of the columns instead of * in SELECT clause.
Try this:
insert into book(title,author,price,amount)
select title,author,price,amount from supply;
I have a table which represents the hierarchy of departments:
+-----------+--------------+--------------+--------------+-----------+-------+
| Top Dept. | 2-tier Dept. | 3-tire Dept. | 4-tier Dept. | name | tier |
+-----------+--------------+--------------+--------------+-----------+-------+
| 00 | | | | abc | 0 |
| | 00-01 | | | bcd | 1 |
| | | 00-01-01 | | cde | 2 |
| | | 00-01-02 | | abc | 2 |
| | 00-02 | | | aef | 1 |
| | | 00-02-01 | | qwe | 2 |
| | | 00-02-03 | | abc | 2 |
| | | | 00-02-03-01 | abc | 3 |
+-----------+--------------+--------------+--------------+-----------+-------+
now I want to sort the rows which are in the same tier by their names while keeping the hierarchy overall, That's what I expect:
+-----------+--------------+--------------+--------------+-----------+-------+
| Top Dept. | 2-tier Dept. | 3-tire Dept. | 4-tier Dept. | name | tier |
+-----------+--------------+--------------+--------------+-----------+-------+
| 00 | | | | abc | 0 |
| | 00-02 | | | aef | 1 |
| | | 00-02-03 | | abc | 2 |
| | | 00-02-01 | | qwe | 2 |
| | 00-01 | | | def | 1 |
| | | 00-01-02 | | abc | 2 |
| | | 00-01-01 | | cde | 2 |
| | | | 00-02-03-01 | abc | 3 |
+-----------+--------------+--------------+--------------+-----------+-------+
the missing data means null, I'm using Oracle DB, can anyone help me?
EDIT: Actually, it's a simple version of this sql, I've tried to add a new column which concats the values of the first four columns and then order by it and by name, but it did't work.
Update: This appears to be working... SQL Fiddle
All that was really needed from my original comment was to amend name to department in that order in both selects. This allows the engine to sort by name first, while maintaining the hierarchy.
WITH cte(Dept, superiorDept, name, depth, sort)AS (
SELECT
Dept,
superiorDept,
name,
0,
name|| dept
FROM hierarchy h
WHERE superiorDept IS NULL
UNION ALL
SELECT
h2.Dept,
h2.superiorDept,
h2.name,
cte.depth + 1,
cte.sort || h2.name ||h2.dept
FROM hierarchy h2
INNER JOIN cte ON h2.superiorDept = cte.Dept
)
SELECT
CASE WHEN depth = 0 THEN Dept END AS 一级部门,
CASE WHEN depth = 1 THEN Dept END AS 二级部门,
CASE WHEN depth = 2 THEN Dept END AS 三级部门,
CASE WHEN depth = 3 THEN Dept END AS 四级部门,
name,
depth,
sort
FROM cte
ORDER BY sort, name
I have two tables tags and users
Table Name: tags
| id | name |
| 1 | one |
| 2 | two |
| 3 | three |
| 4 | four |
| 5 | five |
Table Name: users
| id | fname | tags |
| 1 | Ram | {1,5} |
| 2 | Sham | {1,2,3,4} |
| 3 | Bham | {1,3} |
| 4 | Kam | {5,2} |
| 5 | Lam | {4,2} |
Expected output:
| id | fname | tags |
| 1 | Ram | one, five |
| 2 | Sham | one, two, three, four |
| 3 | Bham | one, three |
| 4 | Kam | five, two |
| 5 | Lam | four, two |
Trial-1 : using JOIN
SELECT I.id, I.fname, I.tags, J.name FROM users I
JOIN tags J ON J.id = ANY(I.cached_tag_ids)
LIMIT 1
Result:
| id | fname | tags |
| 1 | Ram | one |
| 1 | Ram | five |
Expected:
| id | fname | tags |
| 1 | Ram | one, five |
Your tags should have a INTEGER[] type.
CREATE TABLE users(
id SERIAL,
fname VARCHAR(50),
tags INTEGER[]
);
Then,
SELECT I.id, I.fname, array_agg(J.name)
FROM users I
LEFT JOIN tags J
ON J.id = ANY(I.tags)
GROUP BY fname,I.id ORDER BY id
should work. See sqlfiddle
This question may help.
I have 3 like with many - many relationship
As:
TABLE 1 : select * from student;
| id | name |
| 1 | sone |
| 2 | stwo |
| 3 | sthree |
| 4 | sfour |
| 6 | ssix |
TABLE 2 : select * from course;
| id | name |
| 100 | CSE |
| 101 | ECE |
| 102 | ITI |
RELATION_SHIP TABLE : select * from student_course
| id | stu_id | cou_id |
| 1 | 1 | 101 |
| 2 | 2 | 102 |
| 3 | 2 | 100 |
| 4 | 3 | 100 |
| 5 | 3 | 101 |
| 6 | 1 | 101 |
| 1 | 6 | 101 |
I need to write a query to select a student with exactly one course 'CSE' and he should not have any other courses.
Thanks in advance
Use query:
SELECT
sc.`stu_id`,
COUNT(sc.`cou_id`) AS cnt
FROM
student_course sc
GROUP BY sc.`stu_id`
HAVING cnt = 1
AND GROUP_CONCAT(cou_id) LIKE
(SELECT
id
FROM
course
WHERE NAME = 'CSE')