I have table Orders in Mysql, that contains orders.
Each order has some reviews in another table OrdersReviews.
How to execute procedure after specific time after creating order?
My logic is:
After adding order to table, fix added time and order id. Then tell procedure to launch after as sample: current time >order added time + 30`
Does Mysql support something like thatç like cron manager?
WAITFOR COMMAND
I think this is what you are looking for. The comand blocks the execution of the procedure for the time you want and then continues.
It is very useful because you shall combine it with triggers, other stored procedures and even set functions.
Here is the link, good luck.
Related
Sorry for asking this question, but I am a beginner in SQL, my colleague at work build a view, which I need as datasource for a report, however since this view is based on several other views it takes like 45 minutes to execute the query. This is way to long. Therefore I created a table from that view, initial execution time is the same, but once in place it executes in seconds.
In Microsoft SQL Server 2014 I used the following query:
select *
into [dbo].[MAT_v_demnew_daily_am_all_data]
from [dbo].[v_demnew_daily_am]
This works fine, but since the view is updated daily I also need to refresh the table everyday. When I now execute the above mentioned query I get the message that the table already exists.
That's why I tried to use 'insert' in this case:
insert into [dbo].[MAT_v_demnew_daily_am_all_data]
select *
from [dbo].[v_demnew_daily_am]
Here I have the problem that it not only inserts the additional data but also the already existing data, so in the end I have duplicates.
As a workaround I now manually delete the [dbo].MAT_v_demnew_daily_am_all_data] table and then execute the select * into query.
Now I am looking for an easier solution, is it possible to having the table deleted by query and in the same query create a new one by select * into or is it possible to only insert new data from the view to the table so that I don't get duplicates.
Moreover, is it possible to have such SQL statement being executed automatically on a daily basis, maybe by .bat file and windows task scheduler?
I know that the source of all problems is the View and that we should improve that, but looking for a short term solution first.
Thanks so much.
Mathias
Try this:
IF OBJECT_ID('dbo.MAT_v_demnew_daily_am_all_data', 'U') IS NOT NULL
DROP TABLE dbo.MAT_v_demnew_daily_am_all_data
SELECT INTO dbo.MAT_v_demnew_daily_am_all_data FROM dbo.v_demnew_daily_am
This query is reusable on a daily basis.
You can create one stored procedure including this query.
Then you only need to execute the stored procedure.
Updated
Before you create the stored procedure, please check if you have the permission.
Then try:
create procedure [procedure_name]
as
IF OBJECT_ID('dbo.MAT_v_demnew_daily_am_all_data', 'U') IS NOT NULL
DROP TABLE dbo.MAT_v_demnew_daily_am_all_data
SELECT INTO dbo.MAT_v_demnew_daily_am_all_data FROM dbo.v_demnew_daily_am;
After you create it:
EXEC [procedure_name];
I want to take database script backup every day using event in mySql ..I am new to mySql , so unable to find out exact solution..can anybody help me to do so??
Tried it using mysqldump utility but it is command promt oriented , i want it to be done through event scheduler only.
DELIMITER $$
create EVENT `Backup`
ON SCHEDULE EVERY 1 minute
STARTS '2016-02-25 17:08:06' ON COMPLETION PRESERVE ENABLE
DO
BEGIN
SET #sql_text = CONCAT("SELECT * FROM purpleaid INTO OUTFILE '/C:/Users/Admin123/Desktop/db/" , DATE_FORMAT( NOW(), '%Y%m%d') , "db.csv'" );
PREPARE s1 FROM #sql_text;
EXECUTE s1;
DEALLOCATE PREPARE s1;
END $$
DELIMITER ;
tried this , but its for single table only.I want complete database script
You can use information_schema.tables table to get list of tables within a database, and information_schema.columns table to get list of columns (just in case you want to have column names included in the backup files).
Create a cursor by getting all table names from your database
Loop through the cursor and get the table name into a variable
Construct your select ... into outfile ... statements the same way as you do in your current code, just add the table name from the variable.
Execute the prepared statement.
If you want to add the column names dynamically to the output, then combine Joe's and matt's answers from this SO topic.
UPDATE
For views, stored procedures, functions, and triggers (and tables, for that matter) the issue is that you can't really interact with show create ... statements' results within sql. You can try to recreate their definitions from their respective information_schema tables, but as far as I know, it is not possible to fully reconstruct each object just based on these tables. You need to use an external tool for that, such us mysqldump. If you want a full backup option, then you would be a lot better off, if you used an external tool, that is scheduled by the OS' task scheduler.
Since table structures and other database objects do not change that often (at least, not in production), you can use external tool to back up the structure and use the internal scheduled script to regularly back up the contents.
I would like to set up MySQL so that it can subtract one from all values in a row every minute. Once that value equals 0, I would like MySQL to delete that row, and execute a query which adds a row to another table. Before I ask how this can be done, I first would like to know if such a thing is even possible. I have looked around on Google using the search term "automatic run sql query", and unless I am incorrectly understanding what I have read, it is possible, but how can I do something like what I want? What I want would need an if statement to work, but does MySQL even have such a thing as if statements?
You can use the recurrent option in the MySQL event scheduler. You an set it to run every min and then have your logic in it.
http://dev.mysql.com/doc/refman/5.1/en/events-overview.html
Using recurrent event will help you to accomplish this. Create an event to execute every minute.
CREATE EVENT subtractRow
ON SCHEDULE
EVERY 1 MINUTE
STARTS NOW
ON COMPLETION PRESERVE
COMMENT 'Row Subtraction'
DO
-- WRITE QUERY TO SUBTRACT ROW VALUE HERE
For a smart metering application i would like to aggregate counter data every hour.
For this a query like 'select sum(value) as GasCounter from data where channel_id=8' gives the actual counter value.
For another display task i need this as data of channel 25 every hour in the same table 'data'. Therefor i have to add a dataset and put a valid unix-timestamp in the field 'timestamp' and the sum value in the field 'value'.
All this must be done every hour.
Can Mysql do all that just by using a routine?
What is the right routine sql? How do i create the routine? How is the trigger done so that the routine is executed everx hour?
I need your help on this!
Thank you!
Create a procedure that process what you need to make your middleware happy and then use an event scheduler to call your procedure every one hour.
I am trying to run an INSERT statement on table X each time I SELECT any record from table Y is there anyway that I can accomplish that using MySQL only?
Something like triggers?
Short answer is No. Triggers are triggered with INSERT, UPDATE or DELETE.
Possible solution for this. rather rare scenario:
First, write some stored procedures
that do the SELECTs you want on
table X.
Then, restrict all users to use only
these stored procedures and do not
allow them to directly use SELECT on table
X.
Then alter the stored procedures to
also call a stored procedure that
performs the action you want
(INSERT or whatever).
Nope - you can't trigger on SELECT - you'll have to create a stored procedure (or any other type of logging facility - like a log file or what ever) that you implicitly call on any query statement - easier if you create a wrapper that calls your query, calls the logging and returns query results.
If you're trying to use table X to log the order of SELECT queries on table Y (a fairly common query-logging setup), you can simply reverse the order of operations and run the INSERT query first, then run your SELECT query.
That way, you don't need to worry about linking the two statements with a TRIGGER: if your server crashes between the two statements then you already logged what you care about with your first statement, and whether the SELECT query runs or fails has no impact on the underlying database.
If you're not logging queries, perhaps you're trying to use table Y as a task queue -- the situation I was struggling with that lead me to this thread -- and you want whichever session queries Y first to lock all other sessions out of the rows returned so you can perform some operations on the results and insert the output into table X. In that case, simply add some logging capabilities to table Y.
For example, you could add an "owner" column to Y, then tack the WHERE part of your SELECT query onto an UPDATE statement, run it, and then modify your SELECT query to only show the results that were claimed by your UPDATE:
UPDATE Y SET owner = 'me' WHERE task = 'new' AND owner IS NULL;
SELECT foo FROM Y WHERE task = 'new' AND owner = 'me';
...do some work on foo, then...
INSERT INTO X (output) VALUES ('awesomeness');
Again, the key is to log first, then query.