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You can use date-sub() and now() function from MySQL to fetch the rows added in last hour.SyntaxThe syntax is as follows −select *from yourTableName where yourDateTimeColumnName create table LastHourRecords -> ( -> Id int, -> Name varchar(100), -> Login datetime -> ); Query OK, 0 rows affected (0.67 sec)Insert records in the form of datetime using insert command. The query to insert record is as follows −mysql> insert into LastHourRecords values(1, 'John', ' 2018-12-19 10:00:00'); Query OK, 1 row affected (0.17 sec) mysql> insert into LastHourRecords values(2, 'Carol', '2018-12-19 10:10:00'); Query OK, 1 row affected (0.15 sec) ... Read More
A ternary operator uses 3 operands and it can be used to replace the if else statement. This can be done to make the code simpler and more compact.The syntax of the ternary operator is given as follows −Expression ? Statement 1 : Statement 2In the above syntax, the expression is a conditional expression that results in true or false. If the value of the expression is true, then statement 1 is executed otherwise statement 2 is executed.A program that demonstrates the ternary operator in Java is given as follows.Example Live Demopublic class Example { public static void main(String[] args) ... Read More
To query for string fields with a specific length, use the char_length() or length() from MySQL.SyntaxThe syntax is as follows −Case 1 − Use of char_length()This can be used when we are taking length in a number of characters.The syntax −select *from yourTableName where char_length(yourColumnName)=anySpecificLengthValue;Case 2 − Use of length()This can be used when we are taking the length in bytes.The syntax −select *from yourTableName where length(yourColumnName)=anySpecificLengthValue;To understand the above concept, let us first create a table. The query to create a table is as follows −mysql> create table StringWithSpecificLength -> ( -> Id int, -> Name varchar(100), -> FavouriteLanguage ... Read More
You can achieve with the help of timestampdiff() method from MySQL. The syntax is as follows −SyntaxSELECT ABS(TIMESTAMPDIFF(HOUR, yourColumnName1, yourColumnName2)) as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table DifferenceInHours -> ( -> StartDateTime datetime, -> EndDateTime datetime -> ); 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 DifferenceInHours values('2018-12-20 10:00:00', '2018-12-19 12:00:00'); Query OK, 1 row affected (0.11 sec) mysql> insert into DifferenceInHours ... Read More
The setBit() method is used in Java to return a BigInteger whose value is equivalent to this BigInteger with the designated bit set.Example Live Demoimport java.math.*; public class BigIntegerDemo { public static void main(String[] args) { BigInteger one, two; one = new BigInteger("7"); two = one.setBit(3); System.out.println("Result: " +two); } }OutputResult: 15Let us see another example.Example Live Demoimport java.math.*; public class Demo { public static void main(String[] args) { BigInteger bi1, bi2; bi1 = new BigInteger("9"); // setbit ... Read More
To get the index of last substring in a given string, use the char_length() function. First, we need to calculate string length and subtract the last sub string length from the entire length. The difference in length is index of substring.SyntaxThe syntax is as follows −select CHAR_LENGTH(yourColumnName) - LOCATE('yourDelimiter ', REVERSE(yourColumnName))+1 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 SubStringIndexDemo -> ( -> Words varchar(200) -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table ... Read More
To clear a bit in a BigInteger in Java, use the clearBit() method. It returns a BigInteger whose value is equivalent to this BigInteger with the designated bit cleared.Example Live Demoimport java.math.*; public class BigIntegerDemo { public static void main(String[] args) { BigInteger one, two; one = new BigInteger("7"); two = one.clearBit(2); System.out.println("Result: " +two); } }OutputResult: 3Let us see another example.Example Live Demoimport java.math.*; public class Demo { public static void main(String[] args) { BigInteger bi1, bi2; bi1 = new ... Read More
To flip a bit in a BigInteger in Java, use the flipBit() method. This method returns a BigInteger whose value is equivalent to this BigInteger with the designated bit flipped.Example Live Demoimport java.math.*; public class Demo { public static void main(String[] args) { BigInteger one, two; one = new BigInteger("7"); one = one.flipBit(3); System.out.println("Result: " +one); } }OutputResult: 15Let us see another example.Example Live Demoimport java.math.*; public class Demo { public static void main(String[] args) { BigInteger bi1, bi2; bi1 = ... Read More
To shift bits in a BigInteger, use the shiftLeft() or shiftRight() method.shiftLeft() methodThe java.math.BigInteger.shiftLeft(int n) returns a BigInteger whose value is (this > n). Sign extension is performed. The shift distance, n, may be negative, in which case this method performs a left shift. It computes floor(this / 2n).Example Live Demoimport java.math.*; public class Demo { public static void main(String[] args) { BigInteger one; one = new BigInteger("25"); one = one.shiftRight(3); System.out.println("Result: " +one); } }OutputResult: 3
To make a primary key start from 1000, you need to alter your table and set to auto_increment with value 1000. The syntax is as follows −alter table yourTableName auto_increment=1000;To understand the above syntax, let us first create a table. The query to create a table is as follows −mysql> create table PrimaryKey1000Demo -> ( -> ProductId int auto_increment, -> PRIMARY KEY(ProductId) -> ); Query OK, 0 rows affected (0.56 sec)Now here is the query that will update the primary key to start from 1000 −mysql> alter table PrimaryKey1000Demo auto_increment=1000; Query OK, 0 rows affected (0.20 ... Read More