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To prevent a combination of items from being inserted twice, alter the table and set UNIQUE for the column as shown in the below syntax −alter table yourTableName add constraint yourConstraintName unique(yourColumnName1, yourColumnName2, ....N);Let us first create a table −mysql> create table DemoTable ( Value1 int, Value2 int ); Query OK, 0 rows affected (0.47 sec)Here is the query to prevent a combination of items from being inserted twice −mysql> alter table DemoTable add constraint Value1_Value2_ConstraintKey unique(Value1, Value2); Query OK, 0 rows affected (0.80 sec) Records : 0 Duplicates : 0 Warnings : 0Insert some records in the ... Read More
For this, use BETWEEN -1 AND 1. Let us first create a table −mysql> create table DemoTable ( Value int ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(14); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(15); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(16); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(17); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(18); Query OK, 1 row affected (0.09 sec)Display all records from ... Read More
Let us first create a table −mysql> create table DemoTable ( ProductAmount int, PurchaseDate datetime ); Query OK, 0 rows affected (0.94 sec)Note − Let’s say the current date is 2010-09-15.Insert some records in the table using insert command −mysql> insert into DemoTable values(567, '2019-09-10'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(1347, '2019-09-14'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(2033, '2019-09-13'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(1256, '2019-09-11'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(1000, '2019-09-16'); Query ... Read More
Let us first create a table −mysql> create table DemoTable ( Subject text ); Query OK, 0 rows affected (0.86 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Introduction to MySQL'); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable values('Deep Dive using Java'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('C in Depth'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Introduction to C++'); Query OK, 1 row affected (0.48 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will ... Read More
Let us first create a table −mysql> create table DemoTable ( Joiningdate date ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2010-01-01'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('2010-03-31'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('2010-11-04'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values('2012-12-31'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('2019-01-03'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('2016-04-05'); Query OK, 1 row affected ... Read More
Let us first create a table −mysql> create table DemoTable ( AdmissionDate varchar(50) ); Query OK, 0 rows affected (0.63 sec)Note − Let’s say the current date is 14-Sep-2019.Insert some records in the table using insert command. Following is the query −mysql> insert into DemoTable values('15-Sep-2019'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('14-Sep-2019'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('13-Sep-2016'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('13-Sep-2019'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('13-Sep-2020'); Query OK, 1 row affected ... Read More
Yes, we can implement nested insert with select in MySQL as shown in the below syntax −insert into yourTableName2(yourColumnName1, yourColumnName2, .....N) select yourColumnName1, yourColumnName2, ....N from yourTableName1 where yourCondition;Let us first see an example and create a table −mysql> create table DemoTable1 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(40) ); Query OK, 0 rows affected (0.88 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1(Name) values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1(Name) values('David'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1(Name) values('Bob'); Query ... Read More
Let us first create a table −mysql> create table DemoTable ( PageId int ); Query OK, 0 rows affected (0.85 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(233); Query OK, 1 row affected (0.36 sec) mysql> insert into DemoTable values(34); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(76); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(89); Query OK, 1 row affected (0.26 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+--------+ | PageId | +--------+ ... Read More
For this, you can use DELETE command. Let us first create a table −mysql> create table DemoTable1 ( Id int, Name varchar(20) ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(1, 'Chris'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable1 values(2, 'David'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1 values(3, 'Bob'); Query OK, 1 row affected (0.20 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce the following output −+------+-------+ | Id ... Read More
Strings are used to store a sequence of characters in Java, they are treated as objects. The String class of the java.lang package represents a String.You can create a String either by using the new keyword (like any other object) or, by assigning value to the literal (like any other primitive datatype).String stringObject = new String("Hello how are you"); String stringLiteral = "Welcome to Tutorialspoint";Concatenating StringsYou can concatenate Strings in Java in the following ways −Using the "+" operator − Java Provides a concatenation operator using this, you can directly add two String literalsExampleimport java.util.Scanner; public class StringExample { ... Read More