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Found 4381 Articles for MySQL

1K+ Views
The autoincrement in MySQL gives a unique number every time. By default, it starts at 1. If you want to start from another number, then you need to change the auto-increment value with the help of ALTER command or you can give value at the time of table creation.Let us first create a table −mysql> create table DemoTable ( UniqueNumber int NOT NULL AUTO_INCREMENT, PRIMARY KEY(UniqueNumber) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable ... Read More

96 Views
Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FileID int ) AUTO_INCREMENT=100; Query OK, 0 rows affected (1.36 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FileID) values(50); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(FileID) values(60); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FileID) values(50); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(FileID) values(70); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable(FileID) values(60); Query OK, 1 row affected (0.28 sec) mysql> ... Read More

287 Views
Let us first create a table −mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(50), StudentAge int ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(StudentName, StudentAge) values('Chris', 21); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(StudentName, StudentAge) values('David', 23); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(StudentName, StudentAge) values('Bob', 22); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(StudentName, StudentAge) values('Carol', 21); Query OK, 1 row affected (0.30 sec)Display all records from ... Read More

735 Views
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

187 Views
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

195 Views
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

783 Views
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

342 Views
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

680 Views
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

143 Views
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