Copy 1st 2 rows in same table and insert it with edited column as shown below.
Table 1 (ID is auto increment)
ID | CL1 | CL2 | CL3
1 | A | text1 | NULL
2 | B | text2 | NULL
Table 2
ID | CL3
21 | 45
24 | 63
Converted Table 1
ID | CL1 | CL2 | CL3
1 | A | text1 | NULL
2 | B | text2 | NULL
3 | A | text1 | 45
4 | B | text2 | 63
I know how to copy and insert all the rows with one column duplicated, but changing some column with different value is the problem.
Below is the query to copy all fields with 1 column changed:
INSERT INTO table1 (col1, col2, col3)
SELECT col1, col2, 1
FROM table1 LIMIT 2;
Ex: So now we have table2 which has table1 CL3's values. Now can we get the data from another table and insert them while copying?
Assuming you want the first 2 records from 1 table updated with the values from the 1st 2 rows from another table, then I think you will need to add a sequence number to each one and join based on that.
Something like as follows, but it won't be quick!
INSERT INTO table1 (ID, CL1, CL2, CL3)
SELECT NULL, a.CL1, a.CL2, b.CL3
FROM
(
SELECT CL1, CL2, #cnt1:=#cnt1 + 1 AS cnt
FROM table1
CROSS JOIN (SELECT #cnt1:=0) sub0
ORDER BY ID
LIMIT 2
) a
INNER JOIN
(
SELECT CL3, #cnt2:=#cnt2 + 1 AS cnt
FROM table2
CROSS JOIN (SELECT #cnt2:=0) sub0
ORDER BY ID
LIMIT 2
) b
ON a.cnt = b.cnt
Related
i have table with 2 columns like below
+----------+----------+
| Column A | Column B |
+----------+----------+
| 123 | ABC |
| 123 | XYC |
| 123 | FGH |
| 145 | QWE |
| 147 | YUI |
+----------+----------+
I want to select all values from table but view it like below:
+----------+---------+---------+----------+
| Column A | value 1 | value 2 | value 3 |
+----------+---------+---------+----------+
| 123 | ABC | XYC | FGH |
| 145 | QWE | | |
| 147 | YUI | | |
+----------+---------+---------+----------+
If you're not trying to create extra columns in your output, you can simply use GROUP_CONCAT with the separator of your choice. For example:
SELECT `Column A`,
GROUP_CONCAT(`Column B` SEPARATOR ' | ') AS `Values`
FROM table1
GROUP BY `Column A`
Output:
Column A Values
123 ABC | XYC | FGH
145 QWE
147 YUI
Demo on dbfiddle
I'm not sure how are you going to execute the query? but if you can manage to create dynamic SQL query string to find all duplicates rows and insert each row into a temp table and other values (unique) into a separate temp table. Then create another query to join all temp tables (with duplicate) value into a new data set, union all of them with the (unique) data set.
It may be a long and not a good solution but here's my experiment:
Insert all duplicates rows into #temp tables (3 rows= 3 #temp tables)
SELECT Id,Name
INTO #temp1
FROM TestTable
WHERE Name='ABC'
SELECT Id,Name
INTO #temp2
FROM TestTable
WHERE Name='XYC'
SELECT Id,Name
INTO #temp3
FROM TestTable
WHERE Name='FGH'
Insert all unique rows into single #temptable
SELECT Id,Name
INTO #temp4
FROM TestTable
WHERE Id!=123
Query
SELECT t1.Id,t1.Name as Value1,t2.Name as Value2,t3.Name as Value3
FROM #temp1 t1
INNER JOIN #temp2 t2 on t1.Id=t2.Id
INNER JOIN #temp3 t3 on t1.Id=t3.Id
UNION ALL
SELECT t4.Id,t4.Name as Value1,null as Value2,null as Value3
FROM #temp4 t4
Result
If you want three different columns, you can use row_number() and conditional aggregation:
select a,
max(case when seqnum = 1 then b end) as b_1,
max(case when seqnum = 2 then b end) as b_2,
max(case when seqnum = 3 then b end) as b_3
from (select t.*,
row_number() over (partition by a order by b) as seqnum
from t
) t
group by a;
Considering this table:
+-----+--------+
| id | value |
+-----+--------+
| 1 | 22 |
+-----+--------+
| 2 | 12 |
+-----+--------+
| 3 | 22 |
+-----+--------+
| 4 | 22 |
+-----+ -------+
I can select all where the column value is duplicated like so:
select value from table having count(value) > 1 ;
This will output the Ids 1,3 and 4.
What I'm attempting to do is select where duplicates, but leaving 1 (one) duplicate un selected, so the above would output only the Ids 3 and 4 (or 1 and 3 etc... the duplicate omitted does not matter, only that it is.
How can I achieve this?
This question IS NOT a duplicate of
Using LIMIT within GROUP BY to get N results per group?
You could use an aggregatio function for filter a value for id and the select all the others
select * from table
where (value, id) not in (
select value, max(id)
from table
group by value
having count(value) > 1
)
;
You can do either as:
select *
from test t1
where exists (select 1
from test t2
where t2.value = t1.value
having count(value)>1)
limit 2
OR:
select t1.*
from test t1 inner join
(select value from test t2 having count(value)>1) t2
on t1.value = t2.value
limit 2;
I need to make a query that moves values of only one column one row up ↑ at a time:
+------------+----------------+
| anotherCOL | values_to_loop |
+------------+----------------+
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 8 | 8 |
| 9 | 9 |
| 10 | 10 |
+------------+----------------+
So, the next time i run the query, it should look like this
+------------+----------------+
| anotherCOL | values_to_loop |
+------------+----------------+
| 1 | 2 |
| 2 | 3 |
| 3 | 4 |
| 4 | 5 |
| 5 | 6 |
| 6 | 7 |
| 7 | 8 |
| 8 | 9 |
| 9 | 10 |
| 10 | 1 |
+------------+----------------+
I need to loop the values of only one MYSQL COLUMN, as in move the values one ROW UP ↑ each time I run the query.
Notice: Tables provided are just illustrative, the data is different.
Here's how you can do it within a single UPDATE query:
UPDATE tbl a
INNER JOIN (
SELECT values_to_loop
FROM (SELECT * FROM tbl) c
ORDER BY anotherCOL
LIMIT 1
) b ON 1 = 1
SET a.values_to_loop =
IFNULL(
(SELECT values_to_loop
FROM (SELECT * FROM tbl) c
WHERE c.anotherCOL > a.anotherCOL
ORDER BY c.anotherCOL
LIMIT 1),
b.values_to_loop
)
It works as follows:
Updates all records from tbl
Joins with a temporary table to retrieve the top value of values_to_loop (the one that will go to the bottom)
Set the new value for values_to_loop to the corresponding value from the next row (c.anotherCOL > a.anotherCOL ... LIMIT 1)
Notes:
This works even if there are gaps in anotherCOL (eg: 1, 2, 3, 6, 9, 15)
It is required to use (SELECT * FROM tbl) instead of tbl because you're not allowed to use the table that you're updating in the update query
Faster query when there are no gaps in anotherCOL
If there are no gaps for values in anotherCOL you can use the query below that should work quite fast if you have an index on anotherCOL:
UPDATE tbl a
LEFT JOIN tbl b on b.anotherCOL = a.anotherCOL + 1
LEFT JOIN (
SELECT values_to_loop
FROM tbl
WHERE anotherCOL = (select min(anotherCOL) from tbl)
) c ON 1 = 1
SET a.values_to_loop = ifnull(
b.values_to_loop,
c.values_to_loop
)
I`ve created a sample table and added both a select to get the looped values and update to loop the values in the table. Also, using a #start_value variable to know the "1" which might be other. Try this:
CREATE TEMPORARY TABLE IF NOT EXISTS temp_table
(other_col INT, loop_col int);
INSERT INTO temp_table (other_col, loop_col) VALUES (1,1);
INSERT INTO temp_table (other_col, loop_col) VALUES (2,2);
INSERT INTO temp_table (other_col, loop_col) VALUES (3,3);
INSERT INTO temp_table (other_col, loop_col) VALUES (4,4);
INSERT INTO temp_table (other_col, loop_col) VALUES (5,5);
DECLARE start_value INT;
SELECT start_value = MIN(loop_col) FROM temp_table;
SELECT T1.other_col, ISNULL(T2.loop_col, start_value)
FROM temp_table T1
LEFT JOIN temp_table T2
ON T1.loop_col = T2.loop_col - 1;
UPDATE T1 SET
T1.loop_col = ISNULL(T2.loop_col, #start_value)
FROM temp_table T1
LEFT JOIN temp_table T2
ON T1.loop_col = T2.loop_col - 1;
SELECT *
FROM temp_table;
Let me know if it works for you.
Step by step:
1 - created a temp_table with values 1 to 5
2 - declared a start_value which will keep the lowest value for the column you to need to loop through
3 - select all rows from temp_table self left join with same temp_table. join condition is on loop_col - 1 so it can shift the rows up
4 - the same self left join, but this time update the values in place too.
please note that in case i get a null value, it should be the start_value there, because it cannot match
Perhaps these are what you had in mind:
update T
set values_to_loop = mod(values_to_loop, 10) + 1
update T
set values_to_loop =
coalesce(
(
select min(t2.values_to_loop) from T t2
where t2.values_to_loop > T.values_to_loop
),
(
select min(values_to_loop) from T
)
)
Database: mysql > ver 5.0
table 1: type_id (int), type
table 2: name_id, name, is_same_as = table2.name_id or NULL
table 3: id, table2.name_id, table1.type_id, value (float)
I want to sum values, and count values in table 3 where table2.name_id are same and also include the values of id where is_same_is=name_id. I want to select all data in table3 for all values in table2.
Apologize if my question is not very clear, and if it has already been answered but I am unable to find a relevant answer. Or dont exactly know what to look for.
[data]. table1
id | type
=========
1 | test1
2 | test2
[data].table2
name_id | name | is_same_as
==============================
1 | tb_1 | NULL
2 | tb_2 | 1
3 | tb_3 | NULL
4 | tb_4 | 1
[data].table3
id | name_id | type_id | value
======================================
1 | 1 | 1 | 1.5
2 | 2 | 1 | 0.5
3 | 2 | 2 | 1.0
output:
name_id| type_id|SUM(value)
=======================================================
1 | 1 |2.0 < because in table2, is_same_as = 1
2 | 2 |1.0
I think the following does what you want:
select coalesce(t2.is_same_as, t2.name_id) as name_id, t3.type_id, sum(value)
from table_3 t3 join
table_2 t2
on t3.name_id = t2.name_id
group by coalesce(t2.is_same_as, t2.name_id), t3.type_id
order by 1, 2
It joins the table on name_id. However, it then uses the is_same_as column, if present, or the name_id if not, for summarizing the data.
This might be what you are looking for: (I haven't tested it in MySQL, so there may be a typo)
with combined_names_tab (name_id, name_id_ref) as
(
select name_id, name_id from table2
union select t2a.name_id, t2b.name_id
from table2 t2a
join table2 t2b
on (t2a.name_id = t2b.is_same_as)
)
select cnt.name_id, t3.type_id, sum(t3.value) sum_val
from combined_names_tab cnt
join table3 t3
on ( cnt.name_id_ref = t3.name_id )
group by cnt.name_id, t3.type_id
having sum(t3.value) / count(t3.value) >= 3
Here's what the query does:
First, it creates 'combined_names_tab' which is a join of all the table2 rows that you want to GROUP BY using the "is_same_as" column to make that determination. I make sure to include the "parent" row by doing a UNION.
Second, once you have those rows above, it's a simply join to table3 with a GROUP BY and a SUM.
Note: table1 was unnecessary (I believe).
Let me know if this works!
john...
I have a table1 (records 3), and table2 (records 3).
Where i have field name in both.
Now i want to make a result from those two table
which will show me both table records and take only one if there is duplicate.
from that result i will do main query using like or or other logical statements
So my expected output records will contain 5 rows not 6 rows. How do i do that?
Example:
table1: table2:
+-------------------------+ +--------------------------------+
| Name | ID | Name | ID
+-------------------------- +---------------------------------
| A | 1 | 1 December Name | 4
| B | 2 | D | 5
| 1 December Name | 3 | E | 6
My Expected output is following which works, but does not work when i use WHERE
like to only get '1 December Name':
+-----------------------------------------------------+
| Name | ID
+-----------------------------------------------------
| A | 1 table1
| B | 2 table1
| 1 December Name | 3 table2 or table1 (no unique)
| D | 4 table2
| E | 5 table2
I tried this:
SELECT * FROM
(
(
SELECT name AS name FROM table1
)
UNION
(
SELECT anothername AS name FROM table2
)
) as t
WHERE name like '%1 December Name%'
limit 1,10
Output: Your SQL query has been executed successfully ( Query took 0.2798 sec )
Problem: The following query has no error but it does not find that record which contain '1 December Name'
Follow up: works i know now which ID it used
SELECT NAME, ID, STATUS FROM
(
(
SELECT NAME AS name , id, CONCAT('table1') AS STATUS FROM table1
)
UNION ALL
(
SELECT ANOTHERNAME AS name, id, CONCAT( 'table2' ) AS STATUS FROM table2
)
) AS t
WHERE
t.NAME LIKE '%1 December Name%'
LIMIT 1 , 10;
You can get something similar to what you want:
select name, group_concat(id) from
(select name, 'table1' as id from table1
union all
select name, 'table2' from table2) x
group by name
Output would be:
+------------------------------------+
| Name | ID
--------------------------------------
| A | table1
| B | table1
| 1 December Name | table1,table2
| D | table2
| E | table2
UNION ALL is the right choice (not UNION), because it does not remove duplicates, and preserves row order
Try this
(SELECT name FROM table1 )
UNION (SELECT name FROM table2);