android - Only three records in SQLite database at a time -

-

I am developing an Android application in which I need to keep a record of the three most recent actions the user made on the screen I have these records stored in the SQLite database.

I want to implement a specific feature, such as whenever a fourth action is taken, the least recent record automatically changes with the new one.

I discovered some ways to limit the number of rows, one of them was to use the trigger in the database and I am not very familiar with the use of the trigger.

Please help me implement the functionality.

according to your post, I think that 3 is the only arbitrary number that you said. You have a large database and you want to restrict numbers or rows with a specific limit.

Use the trigger below 

  Trigger trg 1 when the table 1 Press INSERT (Select number (*) from Table 1, delete from BEGIN Table 1; WHERE _id = (SELECT min (_id) from Table 1); Even

Assuming that _id is the identity column, it should work.

If you do not want to use _ID, then the oldest log identification Use a datetime field to which 1 log is entered within the same millisecond fraction (better use min (_id) because it is the primary primary primary key)


Comments

Post a Comment

Popular posts from this blog

apache - 504 Gateway Time-out The server didn't respond in time. How to fix it? -

-
Using a form submission on an embedded iframe , the customer downloads a compressed log file Requested. The request was sent to the server, which is the compressed log files, perform some database operations and returns a compressed file. After just 2 minutes, 504 gateway time-out server did not respond timely message on browser net panel How to fix this error? The log files were taking a long time to compress, and timeout was set to 2min The error was fixed by extending the file file: # # timeout: The number of seconds before getting the time out. # # # Timeout 120 timeout 600
Read more

c# - .net WebSocket: CloseOutputAsync vs CloseAsync -

-
We have a working ASP.NET Web API REST service, which is one of the methods of our controller, HTTPTTEX. .) Socket handler code looks something like this ... Public async task socket handler (AspNetWebSocketContext context) {_webSocket = context.WebSocket; ... while (! Cts.IsCancellationRequested) {WebSocketReceiveResult Results = _webSocket.ReceiveAsync (Input Segment, cts.Token) .Result; WebSocketsStateCollusocketState = _webSocket.State; If (result.MessageType == WebSocketMessageType.Close || currentSocketState == WebSocketState.CloseReceived) {// What should I use. CloseAysnc () or. CloseOutputAsync ()? _webSocket.CloseOutputAsync (WebSocketCloseStatus.NormalClosure, "Client Requested", cts.Token). Wait (); } If (currentSocketState == WebSocketState.Open) {...}}} .What is the difference between .CooseAsync () and CloseOutputAysnc ()? I tried both of them and they both seemed to work fine but some difference should be the same they both describe very similar to...
Read more

c++ - How to properly scale qgroupbox title with stylesheet for high resolution display? -

-
I am trying to apply a stylesheet for QGroupBox (QT4.8), which works on the normal screen ( 96 dpi) high resolution screen (Yoga 2 Pro, 3200x1800, 275 dpi, windows 8.1). The following style looks good on the 275 dpi screen, but the top margins on a regular 96 dpi screen are far too big. QGroupBox {border: 1px solid red; Range radius: 7px; Margin-top: 12x; } QGroupBox :: Title {subcontrol-origin: margin; Subcontrol-position: left above; Padding-left: 10px; Padding-right: 10px; } Changing the top-margin has an effect, but I did not get a proper setting which works on both screens. If I shorten the value, the content of the group box overlaps with the title on 275 dpi screen. I was also playing with units "East", "PX", "MX", "PT". Reading the document I would have guessed, "2 X" was the correct solution, which should be scaled with different screen resolutions. Without the stylesheet, the groupbox works well on both screens. ...
Read more