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

Let us first create a table. Following is the query to create a table in MySQL −mysql> create table DemoTable(    Id int,    Name varchar(30),    CountryName varchar(30),    Age int ); Query OK, 0 rows affected (0.66 sec)Following is the Java code to access MySQL database −import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.Statement; public class AccessMySQLDatabase {    public static void main(String[] args) {       Connection con = null;       Statement st = null;       try {          con = DriverManager.getConnection("jdbc :mysql ://localhost :3306/web?" + "useSSL=false", "root", "123456"); ... Read More

Let us first create a table −mysql> create table DemoTable (    StudentId int,    StudentName varchar(20),    StudentSubject varchar(20) ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 'Chris', 'MongoDB'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(11, 'David', 'MySQL'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(12, 'Bob', 'Java'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(10, 'Carol', 'MySQL'); Query OK, 1 row affected (0.51 sec) mysql> insert into DemoTable values(10, 'Chris', 'MongoDB'); Query ... Read More

Let us first create a table −mysql> create table DemoTable (    Name varchar(40) ) ; Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John.Smith'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable values('Chris Brown'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Chris.Brown'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('David Miller'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values('Chris.Taylor'); Query OK, 1 row affected (0.18 sec)Display all records from the table using select ... Read More

Fir this, you can concatenate 0 with string field with the help of + operator. The scenario here is like we need to fetch numeric “9844” from a string field “9844Bob”.Let us first create a table −mysql> create table DemoTable (    StudentId varchar(100) ); Query OK, 0 rows affected (0.92 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('9844Bob'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('6375DavidMiller'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('007'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable ... Read More

Let us first create a table −mysql> create table DemoTable (    Value float ); Query OK, 0 rows affected (0.95 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(12.4567); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(124.7884); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(45.64643); Query OK, 1 row affected (0.46 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+---------+ | Value | +---------+ | 12.4567 | | 124.788 | | 45.6464 | +---------+ ... Read More

For this, the syntax is as follows −DELIMITER // create trigger yourTriggerName before insert on yourTableName1    for each row    begin          insert into yourTableName2 values (yourValue1, yourValue2, ...N); end ; // DELIMITER ;Let us first create a table −mysql> create table DemoTable1 (    StudentId int,    StudentName varchar(40) ); Query OK, 0 rows affected (0.69 sec)Here is the query to create second table −mysql> create table DemoTable2(    Id int,    Name varchar(40) ); Query OK, 0 rows affected (0.61 sec)Here is the query for trigger before insert −mysql> DELIMITER // mysql> create trigger ... Read More

Let’s say the current date is 2019-09-14 8 :50 :10. Now, we want records from 00 :00 to 2019-09-14 8 :50 :10. Let us now see an example and create a table −mysql> create table DemoTable (    DueDate datetime ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-09-14'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('2019-09-14 8 :00 :10'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('2019-09-14 8 :44 :00'); Query OK, 1 row affected (0.14 sec) mysql> insert ... Read More

Let us first see an example and create a table −mysql> create table DemoTable (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(40),    StudentAge int,    StudentMarks int ); Query OK, 0 rows affected (0.76 sec)Following is the query to know the database structure −mysql> show create table DemoTable;This will produce the following output −+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table         | Create Table                                                                 ... Read More

To exclude records, use MySQL NOT IN(). Let us first create a table −mysql> create table DemoTable (    Id int ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(2); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(3); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(4); Query OK, 1 row affected (0.41 sec) mysql> insert into DemoTable values(5); Query OK, 1 row affected (0.09 sec) mysql> insert into ... Read More