Found 6705 Articles for Database

How to convert an MySQL database characterset and collation to UTF-8?

Ankith Reddy
Updated on 25-Jun-2020 08:10:50

360 Views

Firstly, we will check which MySQL version is currently being used with the help of version() function −The query is as follows −mysql> SELECT version();The following is the output+-----------+ | version() | +-----------+ | 8.0.12 | +-----------+ 1 row in set (0.00 sec)As you can see in the above output, version 8.0.12 is being used. Now, we can check the current character encoding using the following syntax −SELECT CCSA.character_set_name FROM information_schema.`TABLES`T, information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA WHERE CCSA.collation_name -> =T.table_collation AND T.table_schema = "yourDatabaseName" AND T.table_name = "yourTableName";Apply the above query −mysql> SELECT CCSA.character_set_name FROM information_schema.`TABLES`T, information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA WHERE CCSA.collation_name ... Read More

Which one is preferred between a large table or multiple small tables in MySQL?

George John
Updated on 30-Jul-2019 22:30:23

254 Views

It is very difficult to say whether to prefer one large table or multiple small tables. It depends − On the application we are using. On database normalization However, there are many key points, through which we can say that multiple small tables are good in that situation. Suppose many developers are going to develop multiple tables, then there is a need to split them into multiple small tables. A situation when you are giving authority to many developers. This authority is for different parts of data. In this case, a need arise to split into multiple small ... Read More

How can we use nested transactions allowed in MySQL?

Ankith Reddy
Updated on 25-Jun-2020 08:11:48

474 Views

We can allow multiple transactions with the help of START command and SAVEPOINT. Let us create a table with the help of CREATE command.Creating a tablemysql> CREATE table transactionDemo -> ( -> id int auto_increment, -> primary key(id) -> ); Query OK, 0 rows affected (0.76 sec)After that, I will begin a transaction with the help of START command −mysql> START TRANSACTION; Query OK, 0 rows affected (0.00 sec)After that, I am inserting the following record with the help of INSERT command −mysql> INSERT into transactionDemo values(); Query OK, 1 row affected (0.04 sec)We can display a record with the ... Read More

Difference between localhost and 127.0.0.1?

Kiran Kumar Panigrahi
Updated on 01-Dec-2022 08:30:38

6K+ Views

On almost every machine, the localhost and 127.0.0.1 are functionally the same. But, they are not exactly the same. This article is meant for explain the important differences between localhost and 127.0.01. What is Localhost? "localhost" is the machine name or IP address of the host server. You can think of it as the domain name for "127.0.0.1". The localhost allows a network connection to loop back on itself. It is a communication port that is connected to the local server. It helps us in spoofing the network connections when such a network does not exist. We tend to use ... Read More

What is the difference between MySQL stored procedure and function?

Chandu yadav
Updated on 30-Jul-2019 22:30:23

1K+ Views

Stored Procedure In MySQL, a stored procedure can be called with the help of call statement. A stored procedure returns more than one value. A stored procedure returns 0 by default. It cannot be used in SQL query and is based on precompile. Function A function can be called inside the statement. It can return a value with the help of return statement and it returns only one value. A function returns any single value, which can be a table. It can be used in SQL query and isn’t based on precompile.

Updating a MySQL table with values from another table?

George John
Updated on 30-Jul-2019 22:30:23

10K+ Views

We can update another table with the help of inner join. Let us create two tables. Creating a table mysql> CREATE table tblFirst -> ( -> id int, -> name varchar(100) -> ); Query OK, 0 rows affected (0.48 sec) Inserting records mysql> INSERT into tblFirst values(1, 'John'); Query OK, 1 row affected (0.17 sec) mysql> INSERT into tblFirst values(2, 'Bob'); Query OK, 1 row affected (0.26 sec) mysql> INSERT into tblFirst values(3, 'David'); Query OK, 1 row affected (0.20 sec) Displaying ... Read More

What is ROW_NUMBER() in MySQL?

Ankith Reddy
Updated on 25-Jun-2020 08:13:35

3K+ Views

Row_NUMBER() included from MySQL version 8.0. It is a type of window function. This can be used to assign a sequence number for rows. To understand, create a table with the help of CREATE pcommand −Creating a tablemysql> CREATE table rowNumberDemo -> ( -> FirstName varchar(100) -> ); Query OK, 0 rows affected (0.92 sec)Inserting recordsmysql> INSERT into rowNumberDemo values('john'); Query OK, 1 row affected (0.17 sec) mysql> INSERT into rowNumberDemo values('john'); Query OK, 1 row affected (0.29 sec) mysql> INSERT into rowNumberDemo values('Bob'); Query OK, 1 row affected (0.13 sec) mysql> INSERT into rowNumberDemo values('Smith'); Query ... Read More

Simplest way to copy data from one table to another new table in MySQL?

Arjun Thakur
Updated on 25-Jun-2020 08:14:27

1K+ Views

To copy data from one table to another table, firstly we will create a table.Creating first table −mysql> CREATE table FirstTable -> ( -> id int, -> name varchar(100) -> ); Query OK, 0 rows affected (0.61 sec)After creating a table, we will insert records.mysql> INSERT into FirstTable values(1, 'john'); Query OK, 1 row affected (0.20 sec) mysql> INSERT into FirstTable values(2, 'Smith'); Query OK, 1 row affected (0.21 sec)We can display all the records with the help of SELECT statement −mysql> SELECT * From FirstTable; The following is the output+------+-------+ | id | name | ... Read More

Pagination using MySQL LIMIT, OFFSET?

George John
Updated on 25-Jun-2020 07:53:00

6K+ Views

Firstly, we need to create a table with some records, then we will use pagination with the help of limit and offset.Creating a table with the help of CREATE command. The query is as follows −mysql> CREATE table limitoffsetDemo -> ( -> id int, -> FisrtName varchar(200) -> ); Query OK, 0 rows affected (0.45 sec)After creating a table, we will insert records with the help of INSERT command.Inserting recordsmysql> INSERT into limitoffsetDemo values(1, 'John'); Query OK, 1 row affected (0.11 sec) mysql> INSERT into limitoffsetDemo values(2, 'Bob'); Query OK, 1 row affected (0.16 sec) mysql> INSERT into ... Read More

Advantages of using MySQLi over MySQL?

Ankith Reddy
Updated on 30-Jul-2019 22:30:23

3K+ Views

MySQLi is also known as MySQL improved Extension. It is a relational SQL database management system. It is often used inside PHP to provide an interface with the MySQL databases. Some of the reasons why MySQLi is famous are given below − MySQLi uses the standard form of the SQL language. MySQLi is free as it is released under an open source license. MySQLi can be easily used with PHP which is the most famous language for web development. MySQLi is a very powerful language and it can handle the functionality of powerful database packages. MySQLi can work with ... Read More

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