This page contains the list commonly asked MySQL interview questions and answers. MySQL is an open-source relational database management system (RDBMS) owned by Oracle, though initially owned and sponsored by a single for-profit firm, the Swedish company MYSQLAB. The complete source code of MySQL is accessible under the GNU General Public License terms.
Q1: In which language MySQL is developed?
MySQL is developed in C & C++ and its SQL parser is written in yacc programming language.
Q2: What is Technical Specification of MySQL?
Below are the technical specification of MySQL database:
- High performance
- Flexible structure
- Replication and high availability
- Security and storage management
- Easy to manage and use
Q3: How to display the current date and time using MySQL Query?
Use the below MySQL query to display the current date and time:
Below query will display only date:
Q4: What is limitation to add columns to create for an index?
You can create maximum of 16 indexed columns for a standard MySQL table.
Q5: How do you create an alias in MySQL?
Use the below MySQL query to create an alias in MySQL database:
SELECT t.order_id, orders.customer_id, t.total, orders.order_placed_date FROM # List of all orders and total order values (alias t) ( SELECT order_id, SUM(purchase_price * quantity) AS total FROM products_to_orders GROUP BY order_id ) AS t INNER JOIN orders ON t.order_id = orders.order_id;
Q6: What is default port for MySQL Server?
The default port of MySQL server is 3306.
Q7: How can you dispaly the all indexes defined for a database table?
Use the below MySQL query to display the all nindexes defined for a database table:
SHOW INDEX FROM
Q8: What is InnoDB?
The InnoDB is a database storage engine used for the safe database transactions. It was developed by Inno Oy, now Oracle Corporation.
Q9: How many types of JOINS in MySQL?
Below are the list of joins which you can used in MySQL:
1) Inner join
1.1) equi join
1.2) natural join
2.3) full join
3) Cross join
Q10: How to get only the distinict columns values in MySQL?
Use the MySQL query to get only the distinict columns values from table:
SELECT DISTINCT column_name FROM table_name ;
Q11: How many TRIGGERS are possible in MySQL?
There are six type of triggers to use in MySQL database table.
- Before Insert
- After Insert
- Before Update
- After Update
- Before Delete
- After Delete
Q12: How to concatenate two fields in MySQL?
Use the below MySQL query to concatenate two fields in MySQL:
SELECT CONCAT(column1,column2) FROM table_name
Q13: List out the storage engines which MySQL support?
Below is the list of storage engines which MySQL support:
Q14: How do you get a portion of a string?
Use the below Mysql Query to get a portion of a string:
SELECT SUBSTR(name, 1, 10) from questions;
Q15: How do you convert a string to UTF-8?
Use the below MySQL query to convert a string to UTF-8 using MySQl query:
SELECT (question USING utf8);
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