SQL

• What is SQL used for?

  To manage data in a relational database
• What can you do with SQL in relation to data?

  Retrieve, update, insert, and delete data
• What does VARCHAR(n) represent in SQL?

  Variable length string of max length n
• What does CHAR(n) represent in SQL?

  Fixed length string of n characters
• What data type is used for dates in SQL?

  DATE
• What data type is used for floating point decimal numbers in SQL?

  DOUBLE
• What does BLOB stand for in SQL?

  Binary Large Object
• What is the purpose of the CREATE TABLE command?

  To define a database table
• How would you insert a new student record in SQL?

  Using INSERT INTO command
• What SQL command updates a student's first name and age?

  UPDATE student SET firstName = "India", age = 14
• What does the SELECT command do in SQL?

  Retrieves data from a database
• How do you terminate SQL commands?

  With a semi-colon
• What type of language is SQL?

  Declarative language
• What are the types of SQL languages and their purposes?

  • Data Definition Language (DDL): Define and modify database
  • Data Query Language (DQL): Retrieve data from database
  • Data Manipulation Language (DML): Insert, update, delete data
  • Data Control Language (DCL): Grant and revoke permissions
  • Data Transmission Language (DTL): Manage transactions
• What is the purpose of Data Definition Language (DDL)?

  To define and modify a database
• What does Data Query Language (DQL) allow you to do?

  Retrieve data from a database
• What is the function of Data Manipulation Language (DML)?

  Insert, update, and delete data
• What does Data Control Language (DCL) manage?

  Access permissions for database
• What is the purpose of Data Transmission Language (DTL)?

  Manage transactions