Found 4378 Articles for MySQL

Adding new column after a specific column and defining a default in MySQL?

Nishtha Thakur
Updated on 30-Jul-2019 22:30:26

1K+ Views

You need to follow some steps to add a new column after a specific column and defining default value. In order to achieve this, you need to use ALTER command. Let us first create a table −mysql> create table DemoTable    (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentFirstName varchar(20),    StudentAge int,    StudentCountryName varchar(100)    ); Query OK, 0 rows affected (0.21 sec)Let us check the description of table −mysql> desc DemoTable;This will produce the following output −+--------------------+--------------+------+-----+---------+----------------+ | Field              | Type         | Null | ... Read More

How to use MySQL CASE statement while using UPDATE Query?

Smita Kapse
Updated on 30-Jul-2019 22:30:26

448 Views

For using MySQL CASE statement while using UPDATE Query, you can use CASE statement. Let us first create a table −mysql> create table DemoTable    (    UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserScore int    ); Query OK, 0 rows affected (0.29 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(UserScore) values(100); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable(UserScore) values(110); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(UserScore) values(120); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable(UserScore) values(200); Query OK, 1 ... Read More

MySQL query to select a row which contains same number in a column with set of numbers separated by comma?

Anvi Jain
Updated on 30-Jul-2019 22:30:26

108 Views

You need to use FIND_IN_SET() for this. Let us first create a table −mysql> create table DemoTable ( CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, CustomerName varchar(20), CustomerAllProductPrice text ); Query OK, 0 rows affected (0.30 sec)Insert some records in the table using insert command. Here, we are inserting numbers separated by comma −mysql> insert into DemoTable(CustomerName, CustomerAllProductPrice) values('Chris', '245, 345, 678, 90, 45, 56, 78'); Query OK, 1 row affected (0.03 sec) mysql> insert into DemoTable(CustomerName, CustomerAllProductPrice) values('Chris', '98, 99, 90, 56, 77'); ... Read More

Performing mathematical operations in MySQL IF then ELSE is possible?

Nishtha Thakur
Updated on 30-Jul-2019 22:30:26

197 Views

For performing mathematical operations and working with conditions, you can consider CASE statement. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    FruitName varchar(100),    FruitPrice int    ); Query OK, 0 rows affected (0.26 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FruitName, FruitPrice) values('Orange', 250); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(FruitName, FruitPrice) values('Banana', 100); Query OK, 1 row affected (0.05 sec) mysql> insert into DemoTable(FruitName, FruitPrice) values('Apple', 150); Query OK, 1 row affected (0.05 sec) ... Read More

MySQL system variable table_type doesn't work?

Smita Kapse
Updated on 30-Jul-2019 22:30:26

58 Views

The variable table_type doesn’t work since this variable is deprecated as of MySQL 5.5.3. Use default_storage_engine instead. Following is the syntax −SET default_storage_engine = yourTableEngine;The table engine name may be InnoDB or MyISAM. Here, we will set engine type to MyISAM −mysql> SET default_storage_engine=MyISAM; Query OK,  0 rows affected (0.00 sec)Let us create a table.mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY ); Query OK,  0 rows affected (0.40 sec)Now check the engine type of above table −mysql> SHOW TABLE STATUS WHERE Name = 'DemoTable';This will produce the following output −+--------------+--------+---------+------------+------+----------------+-------------+------------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+ | Name | Engine | ... Read More

Which MySQL Data Type can be used to store Negative Number?

Anvi Jain
Updated on 30-Jul-2019 22:30:26

1K+ Views

You can use TINYINT data type in MySQL to store negative number. Following is the syntax −CREATE TABLE yourTableName ( yourColumnName TINYINT . . . . N );Let us first create a table with a column set as type TINYINT −mysql> create table DemoTable ( Number tinyint ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert ... Read More

Updating boolean value in MySQL?

Nishtha Thakur
Updated on 30-Jul-2019 22:30:26

463 Views

To update boolean value, you can use SET. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, isMarried boolean    ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(isMarried) values(false); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(isMarried) values(true); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(isMarried) values(true); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(isMarried) values(false); Query OK, 1 row affected (0.13 sec)Display all records ... Read More

Count items in a MySQL table with type ENUM involved?

Smita Kapse
Updated on 30-Jul-2019 22:30:26

707 Views

You can use GROUP BY along with aggregate function COUNT(). Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Size ENUM('S', 'M', 'L', 'XL')    ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Size) values('L'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(Size) values('S'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Size) values('S'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable(Size) values('M'); Query OK, 1 ... Read More

MySQL query to decrease the value of a specific record to zero?

Anvi Jain
Updated on 30-Jul-2019 22:30:26

107 Views

Use SET to decrease the value and WHERE to set the condition for a specific record to be 0. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Number int ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command &minusmysql> insert into DemoTable(Number) values(10); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Number) values(20); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Number) values(1); Query OK, 1 row affected ... Read More

How to concatenate all values of a single column in MySQL?

Nishtha Thakur
Updated on 30-Jul-2019 22:30:26

943 Views

You can use group_concat() along with concat() to concatenate all values of a single column. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(20) ); Query OK, 0 rows affected (0.73 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(FirstName) values('Larry'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('Robert'); ... Read More

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