Mkotla has Published 118 Answers

How can we simulate the MySQL MINUS query?

mkotla
mkotla
Published on 22-Feb-2018 12:51:46
Since we cannot use the MINUS query in MySQL, we will use JOIN to simulate the MINUS query. It can be understood with the help of the following example −ExampleIn this example, we are two tables namely Student_detail and Student_info having the following data −mysql> Select * from Student_detail; +-----------+---------+------------+------------+ ... Read More

How can we enter characters as Hexadecimal (HEX) number in MySQL statement?

mkotla
mkotla
Published on 22-Feb-2018 12:08:26
Following are the two approaches with the help of which we can enter characters as a Hexadecimal number −By prefix ‘X’In this approach we need to quote hexadecimal numbers within single quotes with a prefix of X. Then HEX number string will be automatically converted into a character string.Examplemysql> Select ... Read More

How can I combine the built-in-commands (\g and \G), used for executing a MySQL statement, with each other?

mkotla
mkotla
Published on 22-Feb-2018 10:46:36
As we know that built-in-commands (\G and \g) send the command to MySQL server for execution and both of them have the different format of the result set. For combining them and getting the result without error, we need to write two queries, one query with \G and other with ... Read More

What would be the output if we use a NULL value in an arithmetic expression?

mkotla
mkotla
Published on 22-Feb-2018 10:00:23
As we know that a NULL is no value and it is not the same as zero. MySQL represents a database column as NULL if it does not contain any data. Now, if we will use NULL in any arithmetic expression then the result will be NULL also.Examplemysql> Select 65/NULL, ... Read More

What kind of information is displayed by MySQL DESCRIBE statement?

mkotla
mkotla
Published on 21-Feb-2018 17:18:57
The DESCRIBE statement gives information about MySQL table’s structure.ExampleConsider the constructing of the following table name ‘Employee’ with Create Table statement as follows −mysql> Create table Employee(ID INT NOT NULL PRIMARY KEY AUTO_INCREMENT, Name Varchar(20)); Query OK, 0 rows affected (0.20 sec)Now with the help of ‘DESCRIBE Employee‘ statement, we ... Read More

How to write a MySQL stored function that updates the values in a table?

mkotla
mkotla
Published on 21-Feb-2018 16:33:15
As we know that function is best used when we want to return a result. Hence, when we will create stored functions for manipulating tables like to Insert or Update values then it would be more or less like stored procedures. In the following example, we are creating a stored ... Read More

How can we perform ROLLBACK transactions inside a MySQL stored procedure?

mkotla
mkotla
Published on 21-Feb-2018 15:28:45
As we know that ROLLBACK will revert any changes made to the database after the transaction has been started. To perform the ROLLBACK in MySQL stored procedure we must have to declare EXIT handler. We can use a handler for either sqlexception or SQL warnings. It can be understood with the help of ... Read More

How can we perform COMMIT transactions inside MySQL stored procedure?

mkotla
mkotla
Published on 21-Feb-2018 15:14:05
As we know the START transaction will start the transaction and COMMIT is used to made any changes made after starting the transaction. In the following example, we have created a stored procedure with COMMIT along with START transaction which will insert a new record and commit changes in table ... Read More

How can we see the list, along with other information, stored procedures in a particular MySQL database?

mkotla
mkotla
Published on 21-Feb-2018 12:04:36
We can see only the list of stored procedures in a particular MySQL database by the following query −mysql> SHOW PROCEDURE STATUS WHERE db = 'query'\G *************************** 1. row ***************************                   Db: query                 Name: ... Read More

How can we return to windows command shell from MySQL command line tool?

mkotla
mkotla
Published on 21-Feb-2018 11:06:58
The EXIT or QUIT commands take you returned to windows from MySQL command line tool.mysql> EXITORmysql> QUIT
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