Let us first create a table −mysql> create table DemoTable1897    (    Name varchar(20)    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1897 values('john'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('jace'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('David'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1897 values('Chris'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement ... Read More

For this, use SELECT INTO variable with where clause. Let us first create a table −mysql> create table DemoTable1896    (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(20),    StudentMarks int    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Chris', 56); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('David', 98); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Mike', 89); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1896(StudentName, StudentMarks) values('Sam', ... Read More

Define with NOT NULL, if a column must not be empty. Let us first create a table with one of the columns as NOT NULL −mysql> create table DemoTable1895    (    Id int NOT NULL,    FirstName varchar(20),    LastName varchar(20) NOT NULL    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1895 values(100, 'John', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1895 values(NULL, 'Chris', 'Brown'); ERROR 1048 (23000): Column 'Id' cannot be null mysql> insert into DemoTable1895 values(102, 'Carol', NULL); ERROR 1048 (23000): ... Read More

For this, use unix_timestamp(). Let us first create a table −mysql> create table DemoTable1894    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    DueTime int    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1894 values(); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1894;This will produce the following output −+----+---------+ | ... Read More

In this program, we will connect to a MySQL database and insert a null value into a table using Java's JDBC API. We will use the PreparedStatement class along with the setNull() method to achieve this. After the value is inserted, you can check the table to see how the null value is reflected. Steps to insert null value into a MySQL database Following are the steps to insert null value into a MySQL database − Establish a connection to the MySQL database using the DriverManager.getConnection() method. Define the SQL query that ... Read More

Yes, we can do regex match in a select statement −select yourColumnName from yourTableName where yourColumnName regexp '^yourValue';Let us first create a table −mysql> create table DemoTable1892    (    FirstName varchar(20)    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1892 values('John'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Adam'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Jace'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1892 values('Johny'); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More

Let us first create a stored procedure −mysql> delimiter // mysql> create procedure declare_demo_sp()    begin    declare Value1 int;    declare Value2 int;    set Value1=100;    set Value2=2000;    select Value1,Value2,Value1*Value2 as MultiplicationResult;    end    // Query OK, 0 rows affected (0.00 sec) mysql> delimiter ;Call a stored procedure using CALL command −mysql> call declare_demo_sp();This will produce the following output −+--------+--------+----------------------+ | Value1 | Value2 | MultiplicationResult | +--------+--------+----------------------+ |    100 |   2000 |               200000 | +--------+--------+----------------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.00 sec)

For this, use INSERT ON DUPLICATE KEY UPDATE command. Let us first create a table −mysql> create table DemoTable1891    (    FirstName varchar(20),    UNIQUE KEY(FirstName)    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1891 values('Chris') on duplicate key update  FirstName='Robert'; Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1891 values('David') on duplicate key update  FirstName='Robert'; Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1891 values('Chris') on duplicate key update  FirstName='Robert'; Query OK, 2 rows affected (0.00 sec)Display all records from the table ... Read More

For this, use IF(). Let us first see the current date −mysql> select curdate(); +------------+ | curdate()  | +------------+ | 2019-12-10 | +------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable1890    (    DueDate timestamp    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1890 values('2017-12-10'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1890 values('2021-12-10'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1890 values('2018-04-24'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1890 ... Read More

To sum current month records, use the SUM() and MONTH() function. Let us first create a table −mysql> create table DemoTable1889    (    DueDate date,    Amount int    ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1889 values('2019-12-11', 500); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1889 values('2019-11-11', 1000); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1889 values('2018-12-04', 700); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1889 values('2017-12-10', 300); Query OK, 1 row affected (0.00 sec)Display all records ... Read More