For this, you can use COUNT() along with DISTINCT. The COUNT() method is to count the records. However, the DISTINCT returns distinct records, whereas COUNT() method counts those unique records. Let us first create a table −mysql> create table DemoTable (    PhoneNumber bigint ); Query OK, 0 rows affected (1.29 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(8567789898); Query OK, 1 row affected (0.94 sec) mysql> insert into DemoTable values(8567789898); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable values(9876564534); Query OK, 1 row affected (0.43 sec) mysql> insert into DemoTable ... Read More

To order, use the ORDER BY DESC clause. With that, since we want a single ID, which should be the highest, use LIMIT 1. This will fetch the row with highest ID. Let us first create a table −mysql> create table DemoTable (    Id int,    FirstName varchar(50) ); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 'Chris'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(110, 'Robert'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(120, 'Mike'); Query OK, 1 ... Read More

As stated in the official docs −KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with other database systems.Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Name varchar(50),    Age int ); Query OK, 0 rows affected (0.69 sec)Following is the query for INDEX, which is a synonym to KEY −mysql> create index Name_Age_Index on DemoTable(Name, Age); Query OK, 0 rows affected (0.65 sec) Records: 0 Duplicates: ... Read More

Let us first create a table −mysql> create table DemoTable (    Title text ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('MySQL'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('MongoDB\'s'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('MySQL\'s'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('Java\'s'); Query OK, 1 row affected (0.24 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+-----------+ | Title     ... Read More

Let us first create a table −mysql> create table DemoTable (    StudentName varchar(40),    StudentMarks int ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John', 78); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Chris', 48); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('John', 67); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Chris', 89); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the ... Read More

For this, you can use UNION along with the ORDER BY clause. Let us first create a table −mysql> create table DemoTable1 (    Amount int ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values(234); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1 values(567); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1 values(134); Query OK, 1 row affected (0.43 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce the following output −+--------+ | Amount | +--------+ ... Read More

If there are multiple MySQL keywords in a query, use backticks symbol rather than single quotes. Let us first create a table. Here, we have used two reserved keywords i.e. ‘key’ and ‘Limit’ −mysql> create table DemoTable (    `key` int NOT NULL AUTO_INCREMENT PRIMARY KEY ,    `Limit` int ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(`key`, `Limit`) values(null, 80); Query OK, 1 row affected (0.49 sec) mysql> insert into DemoTable(`key`, `Limit`) values(null, 90); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(`key`, `Limit`) values(null, ... Read More

To skip records in MySQL SELECT, use OFFSET. 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('Chris'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Bob'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.11 sec)Display all records from ... Read More

To speed up SELECT DISTINCT, you can create an index on the column or set of columns. Let us first create a table −mysql> create table DemoTable (    Name varchar(40) ); Query OK, 0 rows affected (1.13 sec)Following is the query to create an index −mysql> create index Name_Index on DemoTable(Name); Query OK, 0 rows affected (1.56 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.15 sec) mysql> insert into ... Read More

Let us first create a table −mysql> create table DemoTable (    Cost int,    Quantity int ); Query OK, 0 rows affected (0.80 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(65, 2); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values(290, 4); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(40, 3); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------+----------+ | Cost | Quantity | +------+----------+ | 65 ... Read More