SQL for Data Science PDF

Why SQL for DATA SCIENCE? The demand for data scientists is high, boasting a median base salary of $110,000 and job satisfaction score of 4.4 out of five. Job postings on Glassdoor and found that SQL is listed as one of the top three skills for a data scientist. SQL is a powerfu...

Why SQL for DATA SCIENCE? The demand for data scientists is high, boasting a median base salary of $110,000 and job satisfaction score of 4.4 out of five. Job postings on Glassdoor and found that SQL is listed as one of the top three skills for a data scientist. SQL is a powerful language that's used for communicating with databases. Every application that manipulates any kind of data needs to store that data somewhere  INTRODUCTION TO DATABASES What is SQL A language used for relational databases Query Data Structured English Query Language SQL is a language used for a database to query data. What is Data Collection of facts in the form of words, numbers, or even pictures. Data is one of the most critical assets of any business. It is used and collected practically everywhere. Example : Your bank stores data about you, your name, address, phone number, account number et cetera. Your credit card company and your paypal accounts also store data about you. Data is important; so, it needs to be secure, and it needs to be stored and accessed quickly.  What is Database Repository of data. It is a program that stores data. A database also provides the functionality for adding, modifying, and querying that data. There are different kinds of databases of different requirements. Relational Database DBMS Database is a A set of software tools The terms database, repository of data. for the data in the database server, database is called a database system, data database management server, and database system or DBMS for management systems short. are often used interchangeably.  RDBMS Set of software tools that controls the data such as access, organization, and storage. RDBMS serves as the backbone of applications in many industries including banking, transportation, health, and so on. Examples of relational database management systems are my SQL, Oracle Database, DB2 Warehouse, and DB2 on Cloud. For most people using a database, there are five simple commands: to create a table - CREATE insert data to populate the table - INSERT select data from the table SELECT update data in the table – UPDATE delete data from the table - DELETE Retrieving Rows From Table Using SELECT Statement Retrieving Subset of Columns Restricting Result Set : WHERE Clause COUNT DISTINCT LIMIT INSERT INSERT MULTIPLE ROWS of Data Science, AI, CS  Excluding records from result sets NOT EQUAL Operator Sorting Data