Question:- How To Improve The Performance Of MySQL SELECT Query?
Answer:- Now this question is one of the MySQL interview questions that should be understood carefully. • Use Indexes • Don’t use “*” • Avoid unnecessary columns • Use DISTINCT and Union solely if necessary • Use short table aliases • Avoid wildcard (%) at the start of LIKE pattern
Question:- How Many Triggers Are Allowed In MySQL Tables?
Answer:- This is among beginner MySQL interview questions. • BEFORE INSERT • AFTER INSERT • BEFORE UPDATE • AFTER UPDATE • BEFORE DELETE • AFTER DELETE
Question:- Mention Different Set Operations Available In MySQL
Answer:- • UNION : Combines results from SELECT queries. Returns all distinct rows. • UNION ALL: Returns all rows from all tables meeting the query. • MINUS: Returns all distinct rows selected by the first query but not the second query. • INTERSECT: Intersection of both the queries
Question:- How To Test Null Value In A Database?
Answer:- A null value is a field with no value present in that particular field. Moreover, the primary key does not allow null value. • = NULL or !=NULL can’t be used • IS NULL: SELECT column_names FROM table_name WHERE column_name IS NULL; • IS NOT NULL: SELECT column_names FROM table_name WHERE column_name IS NOT NULL;
Question:- Illustrate The Difference Between BLOB And TEXT
Answer:- BLOB is Binary Large Objects. It is used to store binary data • Examples: TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB TEXT is Non-binary, character-based string data type • Example: TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT
Question:- Mention The Difference Between DELETE Vs TRUNCATE
Answer:- • DELETE • Deletes the data of a table • Data can be retrieved by Commit and Rollback • Where condition can be used • TRUNCATE • Deletes the data permanently • Commit and Rollback not possible • Where condition cant be used
Question:- Differentiate CHAR Vs VARCHAR
Answer:- • CHAR • Stores the data in fixed-length format • Strings smaller than specified length are padded with space characters • Used for small data • VARCHAR • Stores values in variable length • No padding of spaces • Used to store large data
Question:- What Is SQL Server?
Answer:- Microsoft SQL server is a structured query language that is one of the database management systems ( DBMS) and is designed by Microsoft. DBMS are computer software applications with the capability of interacting with users, various other applications, and databases. The objective of SQL Server is capturing and analyzing data and managing the definition, querying, creation, updating, and administration of the database.
Question:- What Are The Features Of MySQL?
Answer:- It provides cross-platform support, a wide range of interfaces for application programming, and has many stored procedures like triggers and cursors that help in managing the MySQL database.
Question:- How To Check The MySQL Version?
Answer:- We can check the MySQL version on linux using the below command: mysql -v (Linux)
Question:- What Is The Traditional Network Library For A System?
Answer:- In either Windows or POSIX systems, the named pipes provide ways of inter-process communications to connect different processes running on the same machine. It dispenses with the necessity of using network stack, and data can be sent without affecting the performance.
Question:- What Is The Default Port For MySQL Server ?
Answer:- The default port for MySQL server is 3306. Another standard default port is 1433 in TCP/IP for SQL Server.
Question:- What Do DDL, DML, And DCL Stand For?
Answer:- DDL is the abbreviation for Data Definition Language dealing with database schemas, as well as the description of how data resides in a database. For instance CREATE TABLE command. DML denotes Data Manipulation Language which includes commands such as SELECT, INSERT, etc. DCL stands for Data Control Language and includes commands like GRANT, REVOKE etc.
Question:- What Is A Join In MYSQL?
Answer:- This is among the beginner interview questions. In MYSQL joins are used to query data from two or more tables. The query is made using the relationship between certain columns existing in the table. There are four types of joins in MYSQL.
