大约有 6,887 项符合查询结果（耗时：0.0193秒） [XML]
INSERT IF NOT EXISTS ELSE UPDATE?
...RIMARY KEY, event_id INTEGER, track_id INTEGER, value REAL);
CREATE UNIQUE INDEX data_idx ON data(event_id, track_id);
Then you can issue:
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 2, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 5);
...
How to get unique values in an array
...uniques);
For more reliability, you can replace contains with MDN's indexOf shim and check if each element's indexOf is equal to -1: documentation
share
|
improve this answer
|
...
Use LINQ to get items in one List, that are not in another List
... thought it most likely would be suboptimal for Lists. Now for tables with indexed IDs, this would definitely be the way to go.
share
|
improve this answer
|
follow
...
How to force GitHub Pages build?
...found a workaround by modifying my file in Github online editor (open your index.html and edit it on Github website, then commit)
2 - Caching issues
Even after a successful build, I would still see the exact same page on myapp.github.io, and hard reloading with Ctrl + Shift + R wouldn't solve it. ...
How can I force division to be floating point? Division keeps rounding down to 0?
...number but also float. I was using an integer division to calculate a list index and getting an error because of that.
– R. Navega
Dec 16 '18 at 20:46
add a comment
...
Python append() vs. + operator on lists, why do these give different results?
...rt(i, x)
Insert an item at a given position. The first argument is the index of the element before which to insert, so a.insert(0, x) inserts at the front of the list, and a.insert(len(a), x) is equivalent to a.append(x).
...
SQL Call Stored Procedure for each Row without using a cursor
... as with the accepted answer USE WITH CATION: Depending on your table and index structure it can be very poorly performing ( O(n^2) ) since you have to order and search your table every time you enumerate.
– csauve
May 30 '12 at 1:00
...
django test app error - Got an error creating the test database: permission denied to create databas
...dges are - Data: SELECT, INSERT, UPDATE, DELETE, Structure: CREATE, ALTER, INDEX, DROP, Admin: REFERENCES. Not a super-user, but still pretty powerful, so use caution.
– Scott
Jan 6 '16 at 17:52
...
Removing Java 8 JDK from Mac
...atest from Oracle (http://www.oracle.com/technetwork/java/javase/downloads/index.html) and install it.
2) Remove (using rm - if you've got backups, you can revert if you make a mistake) all the JDK6 and JRE6 files.
At this stage, you should see:
% ls /Library/Java/JavaVirtualMachines/
jdk1.7.0_nn...
Best approach to remove time part of datetime in SQL Server
...e like without thinking: adding a function or CAST to a column invalidates index usage. See number 2 here: http://www.simple-talk.com/sql/t-sql-programming/ten-common-sql-programming-mistakes/
Now, this does have an example of later SQL Server optimiser versions managing CAST to date correctly, but...