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Found 6705 Articles for Database

687 Views
For this, you can use the CASE statement along with SUM(). Here, we will be finding the count of Male and Female records from a column with employee gender values. Let us first create a table −mysql> create table DemoTable ( EmployeeGender ENUM('Male', 'Female') ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Male'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Female'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Male'); Query OK, 1 row affected (0.10 sec) mysql> insert into ... Read More

1K+ Views
The @ symbol in a stored procedure can be used for user-defined session variables. Let us first create a table −mysql> create table DemoTable ( StudentName varchar(50) ); Query OK, 0 rows affected (1.30 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John Smith'); Query OK, 1 row affected (1.00 sec) mysql> insert into DemoTable values('John Doe'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Chris Brown'); Query OK, 1 row affected (0.53 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output ... Read More

128 Views
Let us first create a table −mysql> create table DemoTable ( FirstName varchar(100), LastName varchar(100) ); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 'Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('John', 'Doe'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('John', 'Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('Robert', 'Brown'); Query OK, 1 row affected (0.10 sec) mysql> insert ... Read More

143 Views
For this, you can use the property IS NULL for null values in MySQL. Let us first create a table −mysql> create table DemoTable ( Name varchar(100) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(null); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(null); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 ... Read More

152 Views
Let us first create a table −mysql> create table DemoTable ( Id int, ColorName varchar(100) ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 'Red'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(101, 'Green'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(101, 'Blue'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable values(102, 'Yellow'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(100, 'Purple'); Query OK, 1 row affected (0.12 sec) mysql> insert ... Read More

100 Views
Let us first create a table. Here, we have VARCHAR type for value −mysql> create table DemoTable ( Value varchar(100) ); Query OK, 0 rows affected (1.80 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('100'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('1244'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('15789'); Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+-------+ | Value | +-------+ | 100 | ... Read More
Add a new column to table and fill it with the data of two other columns of the same table in MySQL?

948 Views
Let us first create a table −mysql> create table DemoTable ( Price int, Quantity int ); Query OK, 0 rows affected (0.71 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(45, 3); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(90, 2); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(440, 1); Query OK, 1 row affected (0.09 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+-------+----------+ | Price | Quantity | +-------+----------+ | ... Read More

185 Views
Let us first create a table −mysql> create table DemoTable1 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(100) ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1(Name) values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1(Name) values('Robert'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1(Name) values('Mike'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1(Name) values('Sam'); Query OK, 1 row affected (0.07 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce ... Read More

568 Views
Let us first create a table −mysql> create table DemoTable ( AdmissionDate date ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-08-24'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('2019-08-25'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('2019-08-20'); 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 −+---------------+ | AdmissionDate | +---------------+ | 2019-08-24 | | 2019-08-25 | ... Read More

57 Views
Following is the syntax −select *from yourTableName order by yourColumnName*1, yourColumnName;Let us first create a table −mysql> create table DemoTable ( Value varchar(100) ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('90'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('86'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('45'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('85'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('085'); Query OK, 1 row affected (0.14 sec) ... Read More