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You can use IN operator for this.The syntax is as follows −SELECT *FROM yourTableName WHERE yourColumnName IN(‘yourValue1’, ‘yourValue2’, ‘yourValue3’, ...........N);To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table InOperatorDemo -> ( -> ClientId int -> ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into InOperatorDemo values(101); Query OK, 1 row affected (0.19 sec) mysql> insert into InOperatorDemo values(110); Query OK, 1 row affected (0.11 sec) mysql> insert into InOperatorDemo ... Read More
Following is the syntax to count the number of documents in a MongoDB collectionlet anyVariableName= db.getCollection(‘yourCollectionName’); yourVariableName.count();Let us first create a collection with documents> db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e2015e86fd1496b38a1") } >db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Ramit", "CustomerAge":23}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e3515e86fd1496b38a2") } >db.countNumberOfDocumentsDemo.insertOne({"CustomerName":"Adam", "CustomerAge":27, "CustomerCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9a5e4c15e86fd1496b38a3") }Following is the query to display all documents from a collection with the help of find() method> db.countNumberOfDocumentsDemo.find().pretty();This will produce the following output{ "_id" : ObjectId("5c9a5e2015e86fd1496b38a1"), "CustomerName" : "Bob" } { "_id" : ObjectId("5c9a5e3515e86fd1496b38a2"), "CustomerName" : "Ramit", "CustomerAge" ... Read More
You can use system variables character_set_server to know the default server character set in MySQL. Following is the syntax −SHOW VARIABLES LIKE 'character_set_server';Additionally, to u can use collation_server system variable to know the default collation in MySQL. Following is the syntax −SHOW VARIABLES LIKE 'collation_server';Let us execute the above syntaxes to know the default character set and collation.Following is the query −mysql> SHOW VARIABLES LIKE 'character_set_server';This will produce the following output −+----------------------+-------+ | Variable_name | Value | +----------------------+-------+ | character_set_server | utf8 | +----------------------+-------+ 1 row in set (0.25 sec)Following is the ... Read More
To save new Date() in MongoDB, you can use new ISODate(). Let us create a collection with documents −> db.saveDateDemo.insertOne({"UserName":"John", "UserLoginDatetime":new ISODate('2018-01-31 12:34:56')}); { "acknowledged" : true, "insertedId" : ObjectId("5cbd67d4de8cc557214c0e04") } > db.saveDateDemo.insertOne({"UserName":"John", "UserLoginDatetime":new ISODate('2019-02-01 04:01:10')}); { "acknowledged" : true, "insertedId" : ObjectId("5cbd67e8de8cc557214c0e05") } > db.saveDateDemo.insertOne({"UserName":"John", "UserLoginDatetime":new ISODate('2019-04-22 12:36:45')}); { "acknowledged" : true, "insertedId" : ObjectId("5cbd6805de8cc557214c0e06") }Display all documents from a collection with the help of find() method −> db.saveDateDemo.find().pretty();This will produce the following output −{ "_id" : ObjectId("5cbd67d4de8cc557214c0e04"), "UserName" : "John", "UserLoginDatetime" : ISODate("2018-01-31T12:34:56Z") } { "_id" : ObjectId("5cbd67e8de8cc557214c0e05"), ... Read More
An immutable copy of a duration where some nanoseconds are removed from it can be obtained using the minusNanos() method in the Duration class in Java. This method requires a single parameter i.e. the number of nanoseconds to be subtracted and it returns the duration with the subtracted nanoseconds.A program that demonstrates this is given as follows −Example Live Demoimport java.time.Duration; public class Demo { public static void main(String[] args) { Duration d = Duration.ofSeconds(1); System.out.println("The duration is: " + d); ... Read More
The with() method is also used to create a Quartet tuple in Java.Let us first see what we need to work with JavaTuples. To work with Quartet class in JavaTuples, you need to import the following package −import org.javatuples.Quartet;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Quartet Class in JavaTuples, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file.The following is an example −Exampleimport org.javatuples.Quartet; public class Demo { public static void main(String[] args) { ... Read More
You can use two approaches to know the version of MySQL. In the first approach, you can use version() to know the MySQL Server version. The first approach is as followsSELECT VERSION();In the second approach, you can use SHOW VARIABLES command to know the MySQL version. The second approach is as followsSHOW VARIABLES WHERE Variable_name = 'version';Let us learn about both the syntaxes one by one.Using version()mysql> select version();The following is te output displaying the current version of the MySQL you are using+-----------+ | version() | +-----------+ | 8.0.12 | +-----------+ 1 row in set (0.00 sec)The ... Read More
The value of the required ChronoField for an Instant can be obtained using the get() method in the Instant class in Java. This method requires a single parameter i.e. the ChronoField and it returns the value of the ChronoField that was passed as a parameter.A program that demonstrates this is given as follows −Example Live Demoimport java.time.*; import java.time.temporal.ChronoField; import java.time.temporal.ValueRange; public class Demo { public static void main(String[] args) { Instant i = Instant.now(); int micro = i.get(ChronoField.MICRO_OF_SECOND); System.out.println("The current Instant is: " + i); System.out.println("The MICRO_OF_SECOND ... Read More
The findFirst() method of the LongStream class in Java returns an OptionalLong describing the first element of this stream, or an empty OptionalLong if the stream is empty.The syntax is as follows.OptionalLong findFirst()Here, OptionalLong is a container object which may or may not contain a long value. For OptionalLong, import the following package.import java.util.OptionalLong;To use the LongStream class in Java, import the following package.import java.util.stream.LongStream;Create a LongStream and add elements.LongStream longStream = LongStream.of(25000L, 35000L, 40000L, 50000L, 60000L);Now, get the first element from the stream.OptionalLong res = longStream.findFirst();The following is an example to implement LongStream findFirst() method in Java.Example Live Demoimport java.util.OptionalLong; ... Read More
To add elements to the ArrayBlockingQueue class, use the add() method.The syntax is as followsboolean add(E ele)Here, ele is the element to be added to the queue. To work with ArrayBlockingQueue class, you need to import the following packageimport java.util.concurrent.ArrayBlockingQueue;The following is an example to add elements in Java ArrayBlockingQueue classExample Live Demoimport java.util.concurrent.ArrayBlockingQueue; public class Demo { public static void main(String[] args) { ArrayBlockingQueue q = new ArrayBlockingQueue(7); q.add(100); q.add(250); q.add(300); q.add(450); q.add(550); q.add(600); q.add(700); System.out.println("ArrayBlockingQueue = " + q); } }OutputArrayBlockingQueue = [100, 250, 300, 450, 550, 600, 700]