Showing posts with label temporary table. Show all posts
Showing posts with label temporary table. Show all posts

Wednesday, September 8, 2010

Using MySQL temporary table

1. Create temporary table with the settlements table structure:

CREATE TEMPORARY TABLE sett LIKE settlements;

2. Insert into the temporary table the data from the settlements for a certain date:

INSERT INTO sett (date,symbol,contract,price)
SELECT date,symbol,contract,price
FROM pltracker.settlements
WHERE date = '2010-09-03';

2a. You can do the previous two steps in only one:

CREATE TEMPORARY TABLE sett
SELECT date,symbol,contract,price
FROM settlements
WHERE date = '2010-09-03';

3. Update the date of the data at the temporary table for the specific date of the settlements:

UPDATE sett
SET date = '2010-09-06'
WHERE date = '2010-09-03';

3a. Since you are updating all the data in the table you can use this SQL statement instead:

UPDATE sett
SET date = '2010-09-06';

4. Insert data back into the settlements table:

INSERT INTO settlements (date,symbol,contract,price)
SELECT *
FROM sett;

5. Check that the new data is in place at the settlements table:

SELECT * FROM settlements
WHERE date = '2010-09-06';

6. The temporary table will be automatically drop when you close the session or you can drop it as any other table:

DROP TABLE sett;