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Articles by George John
Page 39 of 79
How to format number to 2 decimal places in MySQL?
You can use TRUNCATE() function from MySQL to format number to 2 decimal places. The syntax is as follows −SELECT TRUNCATE(yourColumnName, 2) as anyVariableName from yourTableName;To understand the above syntax, let us first create a table. The query to create a table is as follows −mysql> create table FormatNumberTwoDecimalPlace -> ( -> Number float -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into FormatNumberTwoDecimalPlace values(123.456); Query OK, 1 row affected (0.13 sec) mysql> insert into FormatNumberTwoDecimalPlace values(1.6789); Query OK, 1 ...
Read MoreC++ Program to Compute the Area of a Triangle Using Determinants
In this section we will see how to find the area of a triangle in 2D coordinate space using matrix determinants. In this case we are considering the space is 2D. So we are putting each points in the matrix. Putting x values at the first column, y into the second and taking 1 as the third column. Then find the determinant of them. The area of the triangle will be half of the determinant value. If the determinant is negative, then simply take the absolute value of it.$$Area\:=\:absolute\:of\begin{pmatrix}\frac{1}{2} \begin{vmatrix} x_1\:\:y_1\:\:1 \ x_2\:\:y_2\:\:1 \ x_3\:\:y_3\:\:1 \end{vmatrix} \end{pmatrix}$$Here we are assuming ...
Read MoreHow to play ringtone/alarm/notification sound in Android?
This example demonstrate about How to play ringtone/alarm/notification sound in Android.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javapackage app.tutorialspoint.com.notifyme; import android.app.NotificationManager; import android.content.Context; import android.media.MediaPlayer; import android.media.RingtoneManager; import android.net.Uri; import android.support.v4.app.NotificationCompat; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import java.util.Objects; public class MainActivity extends AppCompatActivity { private final static String default_notification_channel_id = "default"; @Override protected void onCreate (Bundle ...
Read MoreAdvantage of multiple chip select lines
Let’s consider that the EPROMs we have are having the starting addresses as 4000H, 4400H, …, 5C00H. 4000H in binary is 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0. In such a case, the 74138 has to be selected for the condition A15 A14 A13 = 0 1 0. This can be achieved by the connection shown in below figure which uses two invert gates.The procedure of selecting the chip74138 is denoted by the addresses A15 A14 A13 = 0 1 0 which can be implemented by any gates. We have taken ...
Read MoreHow to log in as a different user on MySQL?
If you want to login as a different user on MySQL, you need to use “mysql -u -p command”. The syntax is as follows to login as a different user.>mysql -u yourUsername -p After pressing enter key Enter password −To understand the above syntax, let us create a user in MySQL. The syntax is as follows −CREATE USER 'yourUserName'@'localhost' IDENTIFIED BY 'yourPassword';Now I am going to create a user with name ‘John’ and password is ‘john123456’. The query is as follows −mysql> CREATE USER 'John'@'localhost' IDENTIFIED BY 'john123456'; Query OK, 0 rows affected (0.15 sec)Now check the user has been ...
Read MoreFetch rows where first character is not alphanumeric in MySQL?
To fetch rows where first character is not alphanumeric, you can use the following regular expression.Case 1 − If you want those rows that starts from a digit, you can use the following syntax −SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[0-9]';Case 2 − If you want those rows that start from an alphanumeric, use the following syntax −SELECT *FROM yourTableName WHERE yourColumnName REGEXP '^[^0-9A-Za-z]' ;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table getRowsFirstNotAlphanumeric -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserPassword varchar(20), -> PRIMARY ...
Read MoreConversions between color systems using Python (colorsys)
The RGB color model, named so because of the initials of the three additive primary colors, is an additive color model in which red, green and blue light are added to reproduce various colors.The RGB color model is used in representation and display of images in electronic systems, such as televisions and computers. It is based on human perception of colors. Other alternative representations of color model are:YIQ: Luminance, Chrominance (used by composite video signals)HLS: Hue, Luminance, SaturationHSV: Hue, Saturation, ValueThe colorsys module defines functions for conversion of color values between RGB color model and three other coordinate systems. In ...
Read MoreDetermine type of sound file using Python (sndhdr)
The sndhdr module in Python's standard library provides utility functions that read the type of sound data which is in a file. The functions return a namedtuple(), containing five attributesfiletypestring representing 'aifc', 'aiff', 'au', 'hcom', 'sndr', 'sndt', 'voc', 'wav', '8svx', 'sb', 'ub', or 'ul'.frameratethe sampling_rate will be either the actual value or 0 if unknown or difficult to decode.nchannelsnumber of channels or 0 if it cannot be determined or if the value is difficult to decodenframeseither the number of frames or -1.sampwidthbits_per_sample, will either be the sample size in bits or 'A' for A-LAW or 'U' for u-LAW.functions in sndhdr ...
Read MoreSound-playing interface for Windows in Python (winsound)
The winsound module is specific to Python installation on Windows operating system. The module defines following functions −Beep()When this function is called a beep is heard from the PC’s speaker. The function needs two parameters. The frequency parameter specifies frequency of the sound, and must be in the range 37 through 32, 767 hertz. The duration parameter specifies duration of sound in .>>> import winsound >>> winsound.Beep(1000, 500)MessageBeep()This function plays a sound as specified in the registry. The type argument specifies which sound to play. Possible values are −-1, MB_ICONASTERISK, MB_ICONEXCLAMATION, MB_ICONHAND, MB_ICONQUESTION, and MB_OK (default).The value -1 produces a ...
Read MoreWhat are the difference ways to replace nulls values in MySQL using SELECT statement?
There are lots of options available to replace NULL values using select statement. You can use CASE statement or IFNULL() or COALESCE()Case 1 − Using IFNULL()The syntax of IFNULL() is as follows −SELECT IFNULL(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 2 − Using COALESCE()The syntax of COALESCE() is as follows −SELECT COALESCE(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 3 − Using CASE statementThe syntax of CASE statement.SELECT CASE WHEN yourColumnName IS NULL THEN ‘yourValue’ ELSE yourColumnName END AS anyVariableName FROM yourTableNameTo understand what we discussed above, let us create a table. The query to create a table is as follows −mysql> create ...
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