I want a query to insert a row into a table I know it is simple but the scenario is the table should not have more than 5 rows. If table has more than five rows I need to remove the old row(Or replace with new row ) (Based on the insert time stamp) then i need to insert a new row.If number of rows less than count 5 then i can directly insert a row.
Please share me the query.
How about something like this.
declare #count int
SELECT #count=COUNT(*)
from EP_ANSWERS
IF (#count<5)
// DO your insert here
ELSE
DELETE FROM TABLE
WHERE inserttimestamp = (SELECT x.inserttimestamp
FROM (SELECT MAX(t.inserttimestamp) AS inserttimestamp
FROM TABLE t) x)
// DO your insert here
If it is impossible for the table to have more than 5 rows:
DELETE FROM yourtable
WHERE 5 <= (SELECT COUNT(*) FROM yourtable)
AND yourtimestamp = (SELECT MIN(yourtimestamp) FROM yourtable)
;
INSERT INTO yourtable ...
;
If it is possible for the table to have more than 5 rows:
DELETE FROM yourtable
WHERE 5 <= (SELECT COUNT(*) FROM yourtable)
AND yourtimestamp NOT IN (SELECT yourtimestamp
FROM yourtable
ORDER BY yourtimestamp DESC
LIMIT 4)
;
INSERT INTO yourtable ...
;
It sounds like you want to put a trigger on the table to maintain this rule, in MySQL the something like this should work
CREATE TRIGGER trg__my_table__limit_rows
BEFORE INSERT
ON my_table
FOR EACH ROW
BEGIN
IF ((SELECT COUNT(1) FROM my_table) = 5)
BEGIN
DELETE FROM my_table
WHERE id = (SELECT MIN(id) FROM my_table) -- change this to fit your logic for which record should be removed
END
END
Some of the code here is in pseudo (you didn't wrote your schema), but i wrote where you need to complete your own code.
DECLARE #NumberOfRowsToInsert INT = -- select from the data you want to insert
DECLARE #MaxNumberOfRows INT = 5
DECLARE #NumberOfExistingRows INT
DECLARE #Query VARCHAR(MAX) = 'SELECT TOP #rows id FROM SomeTable ORDER BY createdDate ASC'
SELECT #NumberOfExistingRows = COUNT(*)
FROM SomeTable
SET #Query = REPLACE(#Query,'#rows',
CAST(#NumberOfRowsToInsert - (#MaxNumberOfRows - #NumberOfExistingRows))) AS VARCHAR(1))
CREATE TABLE #IdsToDelete(id INT PRIMARY KEY)
INSERT INTO #IdsToDelete
EXEC(#Query)
DELETE FROM SomeTable
WHERE id IN (SELECT * FROM #IdsToDelete)
-- insert here..
Related
I have the following query script that is resulting in an error:
SET #row_number = 0;
Drop Table If Exists testtable2;
Create Temporary Table testtable2
SELECT
*
FROM
(SELECT
row_names, (#row_number:=#row_number + 1) AS num, date_add(date_time, INTERVAL 1 MINUTE) AS date_time, meter, kw
FROM
testtable
WHERE
DAY(date_time) = 1
AND HOUR(date_time) = 2) AS testtable2
WHERE
MOD(testtable2.num, 2) = 0;
UPDATE testtable
SET
testtable.date_time = testtable2.date_time
WHERE
testtable.row_names = testtable2.row_names;
The error says Error Code: 1054. Unknown column 'testtable2.row_names' in 'where clause'
I created a temporary table that contains the column date_time but my update query fails to recognize that the column exists. I can run something like SELECT * FROM testtable2; and it returns showing that the column is indeed generated with the correct title. Why can my update not recognize this column?
This is your update statement:
UPDATE testtable
SET testtable.date_time = testtable2.date_time
WHERE testtable.row_names = testtable2.row_names;
What is testtable? You have not defined that. You created testtable2. If you do have testtable, then perhaps you want a join:
UPDATE testtable tt JOIN
testtable2 tt2
ON tt.row_names = tt2.row_names
SET tt.date_time = tt2.date_time;
You actually meant to use CREATE TABLE ... AS construct but in your case it's wrongly formed. It should be like below.
Create Temporary Table testtable2 AS
SELECT
*
FROM
(SELECT
row_names, (#row_number:=#row_number + 1) AS num,
date_add(date_time, INTERVAL 1 MINUTE) AS date_time,
meter,
kw
FROM
testtable
WHERE
DAY(date_time) = 1
AND HOUR(date_time) = 2) AS XXX <-- Here
WHERE
MOD(testtable2.num, 2) = 0;
Issue in your case is, your Temporary table and inline view alias are same. name them differently. See edited query.
You can directly JOIN with the inner query and can perform UPDATE like
UPDATE testtable
JOIN (
SELECT
*
FROM
(SELECT
row_names, (#row_number:=#row_number + 1) AS num, date_add(date_time, INTERVAL 1 MINUTE) AS date_time, meter, kw
FROM
testtable
WHERE
DAY(date_time) = 1
AND HOUR(date_time) = 2) AS testtable2
WHERE
MOD(testtable2.num, 2) = 0 ) xx ON testtable.row_names = xx.row_names
SET
testtable.date_time = xx.date_time;
I have the following SQL update trigger that works properly:
BEGIN
DECLARE myID INT;
SELECT user_id INTO myID FROM writer WHERE writer_id = NEW.writer_id;
IF (NEW.status_id = 2) THEN
INSERT INTO activity (
user_id,
work_id,
activity,
date_created
) VALUES (
myID,
NEW.work_id,
'confirmed',
now()
);
ELSE
INSERT INTO activity (
user_id,
work_id,
activity,
date_created
) VALUES (
myID,
NEW.work_id,
'modified',
now()
);
END IF;
END
I need to add an additional trigger as the following:
CREATE TRIGGER updateWorkStatus AFTER UPDATE ON writer_split
FOR EACH ROW
BEGIN
UPDATE work a
JOIN writer_split b
ON a.work_id = b.work_id AND a.current_version = b.version
SET a.status_id = 2
WHERE a.work_id NOT IN (
SELECT ab.work_id
FROM (SELECT s.work_id
FROM work w INNER JOIN writer_split s
ON w.work_id = s.work_id AND s.status_id != 2) ab
);
END;
when I run this create script, I am getting a syntax error. Any ideas?
For me i will use UPDATE work as a
Is there a way to define an identity column on another column? What I want to accomplish is a table that holds positions of an order and these orders can be put there anytime. So it could be that there are already lets say three positions in the table and it would look somewhat like this:
OrderNumber | OrderPosition
10001 1
10001 2
10001 3
And now I want to add another position without calculating the right value for the OrderPosition column. This is because I want to write new positions for multiple orders into the table and would like to avoid cursoring over the individual orders. I would prefer a solution wher OrderPosition is an identity column that is reseeded based on the OrderNumber column. So that If i add an order position for a new order it would start with 1 and if I add another position for order 10001 it would continue with 4.
Write a Scalar Function that returns the MAX(OrderPosition) based on OrderNumber. Then reference that function in the insert statement of orders
your requirement will not work for identity column.
You need to create custom logic to get from the normal columns and on combination based new no will generate.. like (read comments, only choose one logic)
declare #t table(OrderNumber int, OrderPosition int)
insert into #t values (10001, 1),(10001, 2),(10001, 3),(10001, 4)
select * from #t
--now insert new record with old orderno
declare #seq int = 1
declare #ordernumberNew int = 10001
--Eigher you can use :- insert to more understand
if( exists(select orderposition from #t where OrderNumber = #ordernumberNew ))
begin
set #seq = (select max(OrderPosition) + 1 from #t where OrderNumber = #ordernumberNew )
end
insert into #t values (#ordernumberNew , #seq )
select * from #t
--or another twist of above statement, insert directly as
insert into #t
values
(
#ordernumberNew,
case when exists (select orderposition from #t where OrderNumber = #ordernumberNew )
then (select max(OrderPosition) + 1 from #t where OrderNumber = #ordernumberNew )
else 1 end
)
select * from #t
--Now enter the not exist order no
set #ordernumberNew = 10006
insert into #t
values
(
#ordernumberNew,
case when exists (select orderposition from #t where OrderNumber = #ordernumberNew )
then (select max(OrderPosition) + 1 from #t where OrderNumber = #ordernumberNew )
else 1 end
)
select * from #t
This question already has answers here:
Oracle Replace function
(3 answers)
Closed 9 years ago.
I need to replace the Table1's filed values from Table2's values while select query.
Eg:
Table1:
Org Permission
--------------------------------------
Company1 1,3,7
Company2 1,3,8
Table2:
Permission Permission
--------------------------------------
1 Read
3 Write
7 Execute
8 Delete
I need like this:
Org Permission
--------------------------------------
Company1 Read,Write,Execute
Company2 Read,Write,Delete
I have been following your post since it was tagged in Oracle :D
In oracle it was looking in much possible ways, But in mysql you have to follow it with the help of procedure:
Schema:
create table table1 (org varchar(50), permission_id varchar(50));
create table table2 (permission_id int, permission_name varchar(50));
insert into table1 values ('Company1','1,3,7'),('Company2','1,3,8');
insert into table2 values (1,'Read'),(3,'Write'),(7,'Execute'),(8,'Delete');
Procedure:
DELIMITER $$
DROP PROCEDURE IF EXISTS `Update_Table_data`$$
CREATE PROCEDURE `Update_Table_data`()
BEGIN
declare max_row int;
declare p1 int;
Set p1 = 0;
SET max_row = (SELECT max(#i:=#i+1) AS row_num FROM table2 AS t,(SELECT #i:=0) AS foo);
label1: LOOP
set p1 = p1 + 1;
IF p1 <= max_row THEN
UPDATE Table1
SET permission_id =
replace(permission_id, (select permission_id from
(SELECT #i:=#i+1 AS row_num ,t.* FROM table2 AS t,(SELECT #i:=0) AS foo) a
where row_num = p1),
(select permission_name from
(SELECT #i:=#i+1 AS row_num ,t.* FROM table2 AS t,(SELECT #i:=0) AS foo) a
where row_num = p1));
Iterate label1;
END IF;
LEAVE label1;
END LOOP label1;
-- SET #x = p1;
END$$
DELIMITER ;
and then make a call to update your values :
call Update_Table_data;
Hope it helps :)
See SQLFiddle for initial data and this is resultant data SQLFiddle
UPDATE
organization
SET
permisson = (SELECT
GROUP_CONCAT(VALUE)
FROM
( SELECT
org,
SUBSTRING_INDEX(permisson,',',1) AS `permisson`
FROM
organization
UNION
SELECT
org,
SUBSTRING_INDEX(SUBSTRING_INDEX(permisson,',',2),',',-1) AS `permisson`
FROM
organization
UNION
SELECT
org,
SUBSTRING_INDEX(permisson,',',-1) AS `permisson`
FROM
organization
) AS t
JOIN
permission p
WHERE
p.p_id = t.permisson AND
t.org = organization.org
GROUP BY org
)
Try to replace your numbers using REPLACE.It work properly only when you are using single digit values for permission.
SQL = " SELECT Org, REPLACE(REPLACE(REPLACE(REPLACE(Permission,"1","Read'"),"3","Write'"),"7","Execute'"),"8","Delete'") as Permission FROM myTable "
REPLACE()
I have a column TokenId list in my SQL table "Tokendata".
The TokenId has values say 1,2,3,4,6,7,8,10,11
Here the above tokenIds are occupied. When I query this table, it should give me the next free tokenId, in this case it should be 5.
If TokenId has values say "1,2,3,4,5,6,7,8,10,11,13,20", the query should return me 9.
Can anyone help me with a SQL query for this?
Note: updated to account for cases where 1 is missing, as per the comment.
SELECT
t.TokenId + 1
FROM (
SELECT TokenId
FROM Tokendata
UNION ALL
SELECT 0
) t
LEFT JOIN Tokendata t2 ON t.TokenId = t2.TokenId - 1
WHERE t2.TokenId IS NULL
ORDER BY t.TokenId
LIMIT 1
Here is the answer to my question. But it may not be the optimistic solution. Optimized solutions are welcome
DECLARE #TempTable TABLE
(
TableID int PRIMARY KEY IDENTITY,
TokenId int
)
Insert Into #TempTable
Select tt.TokenId from XLBDataPoint tt where tt.TokenId= 1
DECLARE #RowCount INT
SET #RowCount = (SELECT COUNT(*) FROM #TempTable )
(SELECT
Top 1 t.TokenId + #RowCount
FROM TokenData t
Where t.TokenId+ #RowCount NOT in
(select t2.TokenId FROM TokenData t2)