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

Let us first create a table −mysql> create table DemoTable    -> (    -> Code varchar(100)    -> ); Query OK, 0 rows affected (1.07 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('/101/102/106'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('/110/111/101'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('/111/114/201'); Query OK, 1 row affected (0.47 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+--------------+ | Code         | +--------------+ | ... Read More

You can use IFNULL() for this. Let us first create a table −mysql> create table DemoTable -> ( -> added_date date, -> updated_date date -> ); Query OK, 0 rows affected (0.95 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-01-10', '2019-06-01'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('2019-05-19', NULL); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(NULL, '2019-09-05'); Query OK, 1 row affected (0.18 sec)Display all records from the table using ... Read More

Using backticks around the column name will allow you to use special characters. Let us first create a table −mysql> create table DemoTable    -> (    -> `Student-Id` int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> `Student-Name` varchar(100),    -> `Student-Age` int    -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Chris', 21); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Mike', 19); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Bob', 18); Query OK, ... Read More

Specify format specifier in STR_TO_DATE() method that convertes string to date. Following is the syntax −select STR_TO_DATE(yourColumnName, 'yourFormatSpecifier') from yourTableName;Let us first create a table −mysql> create table DemoTable -> ( -> AdmissionDate varchar(100) -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('01-12-2019'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('15-06-2019'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('21-01-2016'); Query OK, 1 row affected (0.19 sec)Display all records from the table using select statement −mysql> select *from ... Read More

The current date and time is as follows −mysql> select now();OutputThis will produce the following output −+---------------------+ | now()               | +---------------------+ | 2019-06-15 12:24:06 | +---------------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable    ->(    -> ArrivalDate datetime    -> ); Query OK, 0 rows affected (1.15 sec)Insert some records in the table using insert command. Here, we are adding multiple intervals to the DATE_ADD() method −mysql> insert into DemoTable values(DATE_ADD(DATE_ADD(NOW(), INTERVAL 6 MONTH), INTERVAL 1 YEAR)); Query OK, 1 row affected (0.13 sec) ... Read More

For this, you can use GROUP BY clause along with IN(). Let us first create a table −mysql> create table DemoTable    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(100)    -> ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name) values('John'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(Name) values('Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Name) values('David'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(Name) values('Chris'); Query ... Read More

The ERROR 1064 (42000) mainly occurs when the syntax isn’t set correctly i.e. error in applying the backtick symbol or while creating a database without them can also create an error, if you will use hyphen in the name, for example, Demo-Table will result in ERROR 1064 (42000).To remove the error, you need to use backtick around the database name properly or use nothing. Following is the syntax wherein we haven’t used the backtick. This works correctly −create database yourDatabaseName;Since adding hyhen to the database name will result in an error. Let us implement it while creating the database name ... Read More

You can use DISTINCT along with COUNT(). Let us first create a table −mysql> create table DemoTable    -> (    -> Id int,    -> Score int    -> ); Query OK, 0 rows affected (0.95 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 90); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(10, 190); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(11, 230); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(11, 130); Query OK, 1 row affected (0.17 ... Read More

Let’s say we are creating a database “web” −mysql> SHOW CREATE DATABASE web;This will produce the following output displaying the default charset as well −+----------+-----------------------------------------------------------------------------------------+ | Database | Create Database                                                                         | +----------+-----------------------------------------------------------------------------------------+ | web      | CREATE DATABASE `web` /*!40100 DEFAULT CHARACTER SET utf8 COLLATEutf8_unicode_ci */ | +----------+-----------------------------------------------------------------------------------------+ 1 row in set (0.03 sec)If you want to know ... Read More