Tutorial by Examples: w

The TIMESTAMP column will show when the row was last updated. CREATE TABLE `TestLastUpdate` ( `ID` INT NULL, `Name` VARCHAR(50) NULL, `Address` VARCHAR(50) NULL, `LastUpdate` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ) COMMENT='Last Update' ;

Sometimes you need to fetch data asynchronously before passing it to a child component to use. If the child component tries to use the data before it has been received, it will throw an error. You can use ngOnChanges to detect changes in a components' @Inputs and wait until they are defined before a...

We consume rest API as a JSON format and then unmarshal it to a POJO. Jackson’s org.codehaus.jackson.map.ObjectMapper “just works” out of the box and we really don’t do anything in most cases. But sometimes we need custom deserializer to fulfill our custom needs and this tutorial will guide you thro...

If you want to show active network interfaces, type: ifconfig If you want to show also network interfaces that are down, type: ifconfig -a

You could use ethtool, but they are not going to be reboot persistent. If you want to achieve this, edit the following file: sudo vim /etc/network/interfaces And edit the file with needed informations: auto <interface_name> iface <interface_name> inet static address <ip_addres...

The function np.loadtxt can be used to read csv-like files: # File: # # Col_1 Col_2 # 1, 1 # 2, 4 # 3, 9 np.loadtxt('/path/to/dir/csvlike.txt', delimiter=',', comments='#') # Output: # array([[ 1., 1.], # [ 2., 4.], # [ 3., 9.]]) The same file could be read ...

Consider an array of work items. The time needed for an each work item to complete varies greatly. In order to balance the work distribution between blocks it may be prudent for each block to fetch the next item only when previous one is complete. This is in contrast to a-priori assigning items to...

When more than 9 arguments are supplied, the shift [/n] command can be used, where /n means start at the nth argument, n is between zero and eight. Looping through arguments: :args set /a "i+=1" set arg!i!=%~1 call echo arg!i! = %%arg!i!%% shift goto :args Note, in the above exam...

Use rewind to restart the enumerator. ℕ = Enumerator.new do |yielder| x = 0 loop do yielder << x x += 1 end end ℕ.next # => 0 ℕ.next # => 1 ℕ.next # => 2 ℕ.rewind ℕ.next # => 0

If you want to clear your current Activity stack and launch a new Activity (for example, logging out of the app and launching a log in Activity), there appears to be two approaches. 1. Target (API >= 16) Calling finishAffinity() from an Activity 2. Target (11 <= API < 16) Intent intent ...

(Caveat emptor: there are many, many programmers who go into absolute conniptions if they meet code that uses recordsets instead of commands and stored procedures.) <% dim rs, sql dim SelectedUser SelectedUser = request.form("user") if IsNumeric(SelectedUser) then SelectedUser...

To add shadows to text, use the text-shadow property. The syntax is as follows: text-shadow: horizontal-offset vertical-offset blur color; Shadow without blur radius h1 { text-shadow: 2px 2px #0000FF; } This creates a blue shadow effect around a heading Shadow with blur radius To add a...

The syntax for using the aws cli is as follows: aws [options] <command> <subcommand> [parameters] Some examples using the 'ec2' command and the 'describe-instances' subcommand: aws ec2 describe-instances aws ec2 describe-instances --instance-ids <your-id> Example with a ...

Once you understand how to create an HTTP Server with node, it's important to understand how to make it "do" things based on the path that a user has navigated to. This phenomenon is called, "routing". The most basic example of this would be to check if (request.url === 'some/pa...

$ mkdir backup_download_directory && cd !#:1 mkdir backup_download_directory && cd backup_download_directory This will substitute the Nth argument of the current command. In the example !#:1 is replaced with the first argument, i.e. backup_download_directory.

$ mplayer Lecture_video_part1.mkv $ ^1^2^ mplayer Lecture_video_part2.mkv This command will replace 1 with 2 in the previously executed command. It will only replace the first occurrence of the string and is equivalent to !!:s/1/2/. If you want to replace all occurrences, you have to use !!:gs...

$ apt-get install r-base E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root? $ sudo !! sudo apt-get install r-base [sudo] password for <user>:

First make sure you link against the logging library in your Android.mk file: LOCAL_LDLIBS := -llog Then use one of the following __android_log_print() calls: #include <android/log.h> #define TAG "MY LOG" __android_log_print(ANDROID_LOG_VERBOSE, TAG, "The valu...

Get All Annotation //following method returns all annotations object added on map NSArray *allAnnotations = mapView.annotations; Get Annotation View for (id<MKAnnotation> annotation in mapView.annotations) { MKAnnotationView* annotationView = [mapView viewForAnnotation:annotation];...

Sometimes conversion of primitive types to boxed types is necessary. To convert the array, it's possible to use streams (in Java 8 and above): Java SE 8 int[] primitiveArray = {1, 2, 3, 4}; Integer[] boxedArray = Arrays.stream(primitiveArray).boxed().toArray(Integer[]::new); With lowe...