Following is the syntax executing the plus (+) operator −update yourTableName set yourColumnName3=(yourColumnName1+yourColumnName2)The above syntax is only for plus operator. You need to change symbol like -, *, / for other operations. Let us first create a table −mysql> create table DemoTable    -> (    -> Number1 int,    -> Number2 int,    -> AddResult int,    -> MinusResult int,    -> MultiplyResult int,    -> DivideResult int    -> ); Query OK, 0 rows affected (0.89 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Number1, Number2) values(40, 20); Query OK, 1 row affected (0.16 ... Read More

For the current day, you can use CURDATE() method. Let us first create a table −mysql> create table DemoTable    -> (    -> DueDate date    -> ); Query OK, 0 rows affected (1.35 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-06-14' ); Query OK, 1 row affected (0.35 sec) mysql> insert into DemoTable values('2019-06-15'); Query OK, 1 row affected (0.64 sec) mysql> insert into DemoTable values('2019-06-16'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('2018-01-16'); Query OK, 1 row affected (0.29 sec) mysql> insert into ... Read More

Use if() method for this. Let us first create a table −mysql> create table DemoTable    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Number1 int,    -> Number2 int    -> ); Query OK, 0 rows affected (1.15 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Number1, Number2) values(10, 20); Query OK, 1 row affected (0.41 sec) mysql> insert into DemoTable(Number1, Number2) values(0, 32); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable(Number1, Number2) values(40, 0); Query OK, 1 row affected (0.21 sec) mysql> insert ... Read More

Let us first create a table −mysql> create table DemoTable    -> (    -> Number int    -> ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(12); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(14); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(19); Query OK, 1 row affected (0.14 sec) ... Read More

To select month and year in MySQL, you can use MONTH() and YEAR() method. Let us first create a table −mysql> create table DemoTable    -> (    -> DueDate datetime    -> ); Query OK, 0 rows affected (0.90 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-01-21'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('2019-06-15'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('2018-12-01'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('2015-04-01'); Query OK, 1 row affected (0.16 sec) ... Read More

Let us first create a table −mysql> create table DemoTable    -> (    -> StudentId varchar(100)    -> ); Query OK, 0 rows affected (0.71 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John19383'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Carol9999'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('David123456'); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+-------------+ | StudentId   | +-------------+ | John19383 ... Read More

For this, use CASE statement. Let us first create a table −mysql> create table DemoTable    -> (    -> LastName varchar(100)    -> ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Taylor'); Query OK, 1 ... Read More

Yes, you can use below syntax. Following is the syntax −PRIMARY KEY(yourColumnName1, yourColumnName2);Let us first create a table −mysql> create table DemoTable    -> (    -> StudentFirstName varchar(100),    -> StudentLastName varchar(100),    -> StudentAge int,    -> StudentCountryName varchar(100),    -> PRIMARY KEY(StudentFirstName, StudentLastName)    -> ); Query OK, 0 rows affected (0.74 sec)Let us check the description of the table −mysql> desc DemoTable;OutputThis will produce the following output −+--------------------+--------------+------+-----+---------+-------+ | Field              | Type         | Null | Key | Default | Extra | +--------------------+--------------+------+-----+---------+-------+ | StudentFirstName   | ... Read More

No, we cannot. If you still did it, then stored procedure won’t get created. Therefore, first you need to change your DELIMITER from semicolon(;) to others like (// ,??..etc). Following is the syntax −DELIMITER // CREATE PROCEDURE yourProcedureName() BEGIN yourStatement1, . . . . N END // DELIMITER ;Let us implement the above syntax in order to create a stored procedure −mysql> DELIMITER // mysql> CREATE PROCEDURE get_Message()    -> BEGIN    -> SELECT CONCAT("HELLO", " ", "MYSQL USERS");    -> END    -> // Query OK, 0 rows affected (0.23 sec) mysql> DELIMITER ;Now you can call the stored ... Read More

Use DatabaseMetaData class to retrieve MySQL database structure. In this example, we will display all the table names of database “web” using Java with the help of getMetaData().Following is the Java code −Exampleimport java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import com.mysql.jdbc.DatabaseMetaData; public class getDatabaseInformationDemo {    public static void main(String[] args) {       Connection con = null;       try {          con = DriverManager.getConnection("jdbc:mysql://localhost:3306/web?useSSL=false", "root", "123456");          DatabaseMetaData information = (DatabaseMetaData) con.getMetaData();          String allTableName[] = {             "TABLE"   ... Read More