MySQL Articles

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How to implement GROUP by range in MySQL?

Arjun Thakur
Arjun Thakur
Updated on 30-Jul-2019 1K+ Views

To group by range in MySQL, let us first create a table. The query to create a table is as followsmysql> create table GroupByRangeDemo    - > (    - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    - > YourRangeValue int    - > ); Query OK, 0 rows affected (0.78 sec)Now you can insert some records in the table using insert command.The query is as followsmysql> insert into GroupByRangeDemo(YourRangeValue) values(1); Query OK, 1 row affected (0.14 sec) mysql> insert into GroupByRangeDemo(YourRangeValue) values(7); Query OK, 1 row affected (0.15 sec) mysql> insert into GroupByRangeDemo(YourRangeValue) values(9); Query OK, 1 ...

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Exclude certain columns from SHOW COLUMNS in MySQL?

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 396 Views

Let us first create a demo tablemysql> create table excludeCertainColumnsDemo    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(100),    -> StudentAge int,    -> StudentMarks int,    -> StudentAddress varchar(200)    -> ); Query OK, 0 rows affected (0.50 sec)Now you can check the description of table with the help of desc command. The query is as follows −mysql> desc excludeCertainColumnsDemo;The following is the output+----------------+--------------+------+-----+---------+----------------+ | Field          | Type         | Null | Key | Default | Extra          | +----------------+--------------+------+-----+---------+----------------+ | ...

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Can we exclude entries with “0” while using MySQL AVG function?

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 5K+ Views

To exclude entries with “0”, you need to use NULLIF() with function AVG().The syntax is as followsSELECT AVG(NULLIF(yourColumnName, 0)) AS anyAliasName FROM yourTableName;Let us first create a tablemysql> create table AverageDemo    - > (    - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    - > StudentName varchar(20),    - > StudentMarks int    - > ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into AverageDemo(StudentName, StudentMarks) values('Adam', NULL); Query OK, 1 row affected (0.12 sec) mysql> insert into AverageDemo(StudentName, StudentMarks) values('Larry', 23); Query OK, ...

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How to fasten MySQL inserts?

George John
George John
Updated on 30-Jul-2019 182 Views

You can speed the MySQL insert when you are inserting multiple records at the same time with the help of the following syntaxSTART TRANSACTION insert into insertDemo(yourColumnName1, yourColumnName2, ...N) values(yourValue1, yourValue2, ....N), (yourValue1, yourValue2, ....N), .......N commitLet us first create a demo tablemysql> create table insertDemo    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(20),    -> StudentAge int    -> ); Query OK, 0 rows affected (0.72 sec)Insert multiple records at the same time. The query is as follows −mysql> START TRANSACTION; Query OK, 0 rows affected (0.00 sec) mysql> insert into ...

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How to specify exact order with WHERE `id` IN (…) in MySql?

Ankith Reddy
Ankith Reddy
Updated on 30-Jul-2019 832 Views

To specify exact order with where id IN, you need to use find_in_set() function.The syntax is as followsSELECT *FROM yourTableName WHERE yourColumnName IN (yourValue1, yourValue2, yourValue3, ....N) ORDER BY FIND_IN_SET(yourColumnName , ‘yourValue1, yourValue2, yourValue3, ....N’');Let us first create a tablemysql> create table FindInSetDemo    - > (    - > Id int,    - > Name varchar(20),    - > Age int    - > ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into FindInSetDemo values(10, 'John', 23); Query OK, 1 row affected (0.20 sec) mysql> insert ...

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Adding/ concatenating text values within a MySQL SELECT clause?

Arjun Thakur
Arjun Thakur
Updated on 30-Jul-2019 2K+ Views

To add/ concatenate text values within a select clause, you can use concat() function.Let us create a tablemysql> create table ConcatenatingDemo -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(20), -> UserCountryName varchar(20) -> ); Query OK, 0 rows affected (0.82 sec)Now you can insert some records in the table using insert command. The query is as follows −mysql> insert into ConcatenatingDemo(UserName, UserCountryName) values('John', 'US'); Query OK, 1 row affected (0.14 sec) mysql> insert into ConcatenatingDemo(UserName, UserCountryName) values('Carol', 'UK'); Query OK, ...

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Filter the records of current day, month and year in MySQL?

Arjun Thakur
Arjun Thakur
Updated on 30-Jul-2019 801 Views

Let’s say you have a table with UserLoginTime column wherein we have stored some values for sample. This is the login time of users and we want to filter all these records on the basis of current day, month and year i.e. the current date. We will beLet us now create the table we discussed abovemysql> create table userLoginInformation    - > (    - > UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    - > UserName varchar(20),    - > UserLoginTime datetime    - > ); Query OK, 0 rows affected (0.79 sec)Insert some records in the table using ...

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How do I stop a MySQL decimal field from being rounded?

George John
George John
Updated on 30-Jul-2019 683 Views

You can stop rounding decimal field with the help of DECIMAL() function. Here is the demo of a rounded decimal field. For our example, let us first create a demo tablemysql> create table stopRoundingDemo    -> (    -> Amount DECIMAL(7)    -> ); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into stopRoundingDemo values(7836.783); Query OK, 1 row affected, 1 warning (0.43 sec) mysql> insert into stopRoundingDemo values(1737.67); Query OK, 1 row affected, 1 warning (0.23 sec) mysql> insert into stopRoundingDemo values(110.50); Query OK, 1 ...

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Get the last record from a table in MySQL database with Java?

Ankith Reddy
Ankith Reddy
Updated on 30-Jul-2019 2K+ Views

To get data from MySQL database, you need to use executeQuery() method from java. First create a table in the MySQL database. Here, we will create the following table in the ‘sample’ databasemysql> create table javaGetDataDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > FirstName varchar(10), - > LastName varchar(10) - > ); Query OK, 0 rows affected (0.80 sec)Now you can insert some records in the table using insert command.The query is as followsmysql> insert into javaGetDataDemo(FirstName, LastName) values('John', 'Smith'); Query OK, 1 row affected (0.19 sec) mysql> insert into javaGetDataDemo(FirstName, LastName) values('Carol', ...

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How to determine if a value appears in a GROUP BY group in MySQL?

Ankith Reddy
Ankith Reddy
Updated on 30-Jul-2019 1K+ Views

You can use aggregate function SUM() along with IF to determine if a value appears in a GROUP BY group.Let us first create a demo tablemysql> create table GroupbygroupDemo -> ( -> UserId int, -> UserName varchar(20) -> ); Query OK, 0 rows affected (1.48 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into GroupbygroupDemo values(10, 'John'); Query OK, 1 row affected (0.14 sec) mysql> insert into GroupbygroupDemo values(10, 'Carol'); Query OK, 1 row affected (0.08 sec) mysql> insert into ...

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