Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
MySQL Articles
Page 317 of 355
How to keep the connection alive in MySQL Workbench?
To keep connection alive in MySQL Workbench, you need to reach at the following location −Edit -> Preferences -> SQL EditorHere is the snapshot of all the options.After clicking the “Edit” menu, we will select “Workbench Preferences” as shown below −Now, select SQL Editor and set an interval. You can also set the below options to set the connection alive in MySQL Workbench.DBMS connection Keep-alive intervalDBMS connection Read-timeout intervalDBMS connection Timeout intervalHere is the screenshot
Read MoreTwo columns as primary key with auto-increment in MySQL?
Achieve this using MyISAM Engine. Here is an example of two columns as primary key with auto-increment.Creating a table with two columns as primary key −mysql> create table TwoPrimaryKeyTableDemo -> ( -> Result ENUM('First', 'Second', 'Third', 'Fail') not null, -> StudentId int not null auto_increment, -> StudentName varchar(200) not null, -> Primary key(Result, StudentId) -> ) -> ENGINE=MyISAM; Query OK, 0 rows affected (0.20 sec)Inserting records into tablemysql> insert into TwoPrimaryKeyTableDemo(StudentName, Result) values('John', 'Fail'); Query OK, 1 row affected ...
Read MoreInserting multiple rows in MySQL?
Insert multiple rows in MySQL with the help of “values”. You can enclose the values with parentheses set with comma separation. The syntax is as follows to insert multiple rows in MySQL.insert into yourTableName(yourColumnName1, yourColumnName2, ..............yourColumnNameN) values(value1, value2, ...valueN), (value1, value2, ...valueN), (value1, value2, ...valueN), ...........((value1, value2, ...valueN);Let us now first create a table in MySQL −mysql> create table InsertMultipleRowsDemo -> ( -> Id int, -> Name varchar(200), -> Age int -> ); Query OK, 0 rows affected (0.45 sec)Apply the above syntax to insert ...
Read MoreHow to run SQL script in MySQL?
To run SQL script in MySQL, use the MySQL workbench. First, you need to open MySQL workbench.The snapshot is as follows −Now, File -> Open SQL Script to open the SQL script.Alternatively, use the following shortcut key −Ctrl+Shift+OAfter that an option would be visible for you to choose your .sql file from the disk. In my system, the file is located on the Desktop. I will select the same “tblstudent” SQL file as shown in the following screenshot −After browsing .sql files, you need to select the option “Reconnect to database” as shown in the following screenshot −Now, it will ...
Read MoreMySQL's now() +1 day?
The statement now()+1 day itself states that we need to add a day to the current datetime. You can write the above logic like this −now()+interval 1 day;Or you can write same logic with date_add() function from MySQL like this −date_add(now(), interval 1 day);Let us use the above concept with MySQL select statement. The query is as follows −mysql> select now()+ interval 1 day;Here is the sample output that increments a day by 1 −+-----------------------+ | now()+ interval 1 day | +-----------------------+ | 2018-11-23 15:43:10 | +-----------------------+ 1 row in set (0.05 sec)Now, let us see another example ...
Read MoreOrder a MySQL table by two columns?
Order a MySQL table by two columns with the help of below syntax −order by yourColumnName1 DESC, yourColumnName2 DESC;Let us first create a table for our example −mysql> create table OrderByDemo -> ( -> StudentId int, -> StudentName varchar(100), -> StudentAge int -> ); Query OK, 0 rows affected (0.57 sec)Inserting records into the table with the help of insert command. The query is as follows −mysql> insert into OrderByDemo values(1, 'John', 23); Query OK, 1 row affected (0.20 sec) mysql> insert into OrderByDemo values(3, ...
Read MoreHow to get ER model of database from server with MySQL Workbench?
To get ER model of database from server, you need to first launch MySQL Workbench. The snapshot is as follows −After that you need to select the “Database” menu −Database->Reverse EngineerAfter that a wizard will open as in the following screenshot. Add the password and press OK twice.After pressing the OK button, you will get the next wizard and you need to press next button. The following would be visible now −After that you need to select “Model” menu as I have marked in the above wizard.Model->Create Diagram from Catalog Objects After selecting the option, you will get the ER ...
Read MoreChange MySQL default character set to UTF-8 in my.cnf?
To change MySQL default character set to UTF-8 in my.cnf, firstly reach the location of my.cnf file.The following is the screenshot of “my.cnf” file. Firstly, open the C: directory and the “Program Data” folder −Now, click on “MySQL” folder −Now, click the MySQL Server 8.0 folder and open it −After opening MySQL Server 8.0, you will get “my.cnf” file location.After opening my.cnf file, you will get the character-set. Open the file and the following contens are visible −Now you can change the character-set to utf8.
Read MoreMySQL: selecting rows where a column is null?
To select rows where a column is null, you can use IS NULL from MySQL with the help of where clause.The syntax is as follows −select *from yourTableName where yourColumnName IS NULL;Let us first create a table to understand the concept −mysql> create table NULLDemo1 -> ( -> StudentId int, -> StudentName varchar(100) -> ); Query OK, 0 rows affected (1.48 sec)Inserting records into the table. The query to insert records is as follows −mysql> insert into NULLDemo1 values(NULL, 'John'); Query OK, 1 row affected (0.25 sec) mysql> ...
Read MoreWhat is the best way to display in Terminal a MySQL SELECT returning too many fields?
To achieve this, you can use the following syntax in MySQL −select *from yourTableName\G;Here, G can be used for vertical purpose. You need to add yourTableName.Let us create a table in order to understand the above syntax. Creating a table with the help of CREATE command.The following is the query to create a table −mysql> create table TooManyFieldsreturnDemo -> ( -> Id int, -> Name varchar(100), -> Age int -> ); Query OK, 0 rows affected (0.64 sec)Now you can insert records in the table ...
Read More