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Articles on Trending Technologies
Technical articles with clear explanations and examples
MySQL GROUP BY date when using datetime?
To GROUP BY date while using datetime, the following is the syntax −select *from yourTableName GROUP BY date(yourColumnName);To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table groupByDateDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(20), -> UserPostDatetime datetime -> ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into groupByDateDemo(UserName, UserPostDatetime) values('Larry', '2018-01-02 13:45:40'); Query OK, 1 row affected (0.18 sec) mysql> insert ...
Read MoreWhere is the MySQL table data stored in Windows?
In order to know the location of MySQL table data, you can use the below syntax −select @@datadir;You can also use SHOW VARIABLES command for this. Following is the syntax −show variables where Variable_name ='datadir';Let us implement the above syntaxes to know where MySQL table stores data −mysql> select @@datadir;This will produce the following output −+---------------------------------------------+ | @@datadir | +---------------------------------------------+ | C:\ProgramData\MySQL\MySQL Server 8.0\Data\ | +---------------------------------------------+ ...
Read MoreHow to keep two columns in one order in Android sqlite?
Before getting into example, we should know what sqlite data base in android is. SQLite is an open source SQL database that stores data to a text file on a device. Android comes in with built in SQLite database implementation. SQLite supports all the relational database features. In order to access this database, you don't need to establish any kind of connections for it like JDBC, ODBC etc.This example demonstrate about How to keep two columns in one order in Android sqlite.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all ...
Read MoreCreate KeyValue Tuple from a List collection in Java
To create KeyValue tuple from List collection, use the fromCollection() method. Let us first see what we need to work with JavaTuples. To work with KeyValue class in JavaTuples, you need to import the following package:import org.javatuples.KeyValue;Note: Download JavaTuples Jar library to run JavaTuples program. If you are using Eclipse IDE, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file. Refer the below guide for all the steps to run JavaTuples:Steps: How to run JavaTuples program in EclipseThe following is an example to create KeyValue Tuple from List ...
Read MoreRenaming column name in a MongoDB collection?
To rename column name in a collection, you can use $rename operator. Following is the syntaxdb.yourCollectionName.update({}, {$rename: {'yourOldColumName': 'yourNewColumnName'}}, false, true);Let us first create a collection with documents:> db.renamingColumnNameDemo.insertOne({"StudentName":"Larry", "Age":23}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ee2c6d628fa4220163b9a") } > db.renamingColumnNameDemo.insertOne({"StudentName":"Sam", "Age":26}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ee2d0d628fa4220163b9b") } > db.renamingColumnNameDemo.insertOne({"StudentName":"Robert", "Age":27}); { "acknowledged" : true, "insertedId" : ObjectId("5c9ee2dbd628fa4220163b9c") }Following is the query to display all documents from a collection with the help of find() method> db.renamingColumnNameDemo.find().pretty();This will produce the following output{ "_id" : ObjectId("5c9ee2c6d628fa4220163b9a"), "StudentName" : "Larry", "Age" : 23 ...
Read MoreSelect first element of a commaseparated list in MySQL?
To select first element of a comma-separated list, you can use SUBSTRING_INDEX(). Let us first create a table:mysql> create table DemoTable ( CSV_Value varchar(200) ); Query OK, 0 rows affected (0.81 sec)Following is the query to insert some records in the table using insert command. We have inserted records in the form of comma-separated integer list:mysql> insert into DemoTable values('10, 20, 50, 80'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('100, 21, 51, 43'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('1, 56, 103, 1090'); Query OK, 1 row affected (0.26 ...
Read MoreC++ Program that will fill whole memory
In this article we will see how to fill the whole memory by writing a simple C++ program. Here the logic is very simple. We shall create new integer variables by using the dynamic memory allocation. If we create some variables again and again, it will fill the entire primary memory.In C++ to dynamically allocate a memory space we can use the new keyword.The basic syntax of the new operator is like below.pointer_var = new data_typeTo deallocate the memory space, we can use the delete keyword. The syntax isdelete pointer_varNote After running this program it may slow down the performance ...
Read MoreAdd new field to every document in a MongoDB collection?
To add new field to every document in a MongoDB collection, you can use $set operator. The syntax is as follows:db.yourCollectionName.update({}, { $set: {"yourFieldName": yourValue} }, false, true);To understand the above syntax, let us create a collection with some documents. The query to create a collection with documents is as follows:>db.addNewFieldToEveryDocument.insertOne({"StudentName":"John", "StudentAddress":"US "}); { "acknowledged" : true, "insertedId" : ObjectId("5c6efc0b6fd07954a48906ae") } >db.addNewFieldToEveryDocument.insertOne({"StudentName":"David", "StudentAddress":"U K"}); { "acknowledged" : true, "insertedId" : ObjectId("5c6efc0b6fd07954a48906af") } >db.addNewFieldToEveryDocument.insertOne({"StudentName":"Carol", "StudentAddress":"U K"}); { "acknowledged" : true, "insertedId" : ObjectId("5c6efc0b6fd07954a48906b0") } >db.addNewFieldToEveryDocument.insertOne({"StudentName":"Bob", "StudentAddress":"US" }); { "acknowledged" : true, "insertedId" : ...
Read MoreHow to enable vertical scroll bar for android webview?
This example demonstrate about How to set default text encoded for android webview.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. In the above code, we have taken web view to show facebook.com.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.app.ProgressDialog; import android.os.Build; import android.os.Bundle; import android.support.annotation.RequiresApi; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.webkit.CookieManager; import android.webkit.WebChromeClient; import android.webkit.WebSettings; import android.webkit.WebView; import android.webkit.WebViewClient; import android.widget.EditText; public class MainActivity extends ...
Read MorePacket over SONET
Synchronous optical networking (SONET) is a physical layer protocol for transmitting multiple digital bit streams over optical fiber links that form the backbone of the communication networks. Packet-over-SONET (POS) is a standard that maps IP packets into SONET frames. To implement this mechanism, Point – to – Point Protocol (PPP) runs on IP routers. Point – to – Point Protocol (PPP) is a data link layer protocol that is used to transmit data between two directly connected (point-to-point) computers. It is a byte-oriented protocol that is widely used in broadband communications having heavy loads and high speeds.The following diagram shows ...
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