Tutorial by Examples: re

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' ;

Code snippet: import java.util.Set; public class ThreadStatus { public static void main(String args[]) throws Exception { for (int i = 0; i < 5; i++){ Thread t = new Thread(new MyThread()); t.setName("MyThread:" + i); t.start(); ...

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 ...

# example data DT = as.data.table(mtcars, keep.rownames = TRUE) To rearrange the order of columns, use setcolorder. For example, to reverse them setcolorder(DT, rev(names(DT))) This costs almost nothing in terms of performance, since it is just permuting the list of column pointers in the da...

# example data DT = as.data.table(mtcars, keep.rownames = TRUE) To rename a column (while keeping its data the same), there is no need to copy the data to a column with a new name and delete the old one. Instead, we can use setnames(DT, "mpg_sq", "mpq_squared") to modify ...

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...

Automatic Linebreaks Table content is line wrapped automatically if it is too wide. In the following example, text is added to the second column, which causes oth the text itself and the column header of the first column to be wrapped. | this is a really wide column header | another header | | -...

io-streams is Stream-based library that focuses on the Stream abstraction but for IO. It exposes two types: InputStream: a read-only smart handle OutputStream: a write-only smart handle We can create a stream with makeInputStream :: IO (Maybe a) -> IO (InputStream a). Reading from ...

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

When multiple variables are defined at the beginning of the batch, a short definition form may be used by employing a replacement string. @echo off set "vars=_A=good,_B=,_E=bad,_F=,_G=ugly,_C=,_H=,_I=,_J=,_K=,_L=,_D=6 set "%vars:,=" & set "%" for /f %%l in ('set _'...

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 ...

$ 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>:

Using Ubuntu you have different ways to read a text file, all similar but useful in different context. cat This is the simplest way to read a text file; it simply output the file content inside the terminal. Be careful: if the file is huge, it could take some time to complete the printing process!...

public static string CreateBLOBContainer(string containerName) { try { string result = string.Empty; CloudMediaContext mediaContext; mediaContext = new CloudMediaContext(mediaServicesAccountName, mediaServicesAccou...

private static void GetAllTheAssetsAndFiles(MediaServicesCredentials _medServCredentials) { try { string result = string.Empty; CloudMediaContext mediaContext; mediaContext = new CloudMediaContext(_medServCredentials); ...

With a clustered index the leaf pages contain the actual table rows. Therefore, there can be only one clustered index. CREATE TABLE Employees ( ID CHAR(900), FirstName NVARCHAR(3000), LastName NVARCHAR(3000), StartYear CHAR(900) ) GO CREATE CLUSTERED INDEX IX_Clustered O...

Non-clustered indexes have a structure separate from the data rows. A non-clustered index contains the non-clustered index key values and each key value entry has a pointer to the data row that contains the key value. There can be maximum 999 non-clustered index on SQL Server 2008/ 2012. Link for r...