Insert statement is used to insert new rows in to table. Update to update existing data in the table. Delete statement to delete a record from the table. Below code snippet for Insert, Update and Delete :- INSERT INTO pcdsEmployee SET name=’rohit’,age=’24’; UPDATE pcdsEmployee SET age=’25’ where name=’rohit’; DELETE FROM pcdsEmployee WHERE name = ‘sonia’; Sure, here’s a brief explanation of Insert, Update, and Delete queries in a database management system (DBMS): Insert Query: An Insert query is used to…

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Data Warehousing is a process in which the data is stored and accessed from central location and is meant to support some strategic decisions. Data Warehousing is not a requirement for Data mining. But just makes your Data mining process more efficient. Data warehouse is a collection of integrated, subject-oriented databases designed to support the decision-support functions (DSF), where each unit of data is relevant to some moment in time.

SQL IN operator is used to see if the value exists in a group of values. For instance the below SQL checks if the Name is either ‘rohit’ or ‘Anuradha’ SELECT * FROM pcdsEmployee WHERE name IN (‘Rohit’,’Anuradha’) Also you can specify a not clause with the same. SELECT * FROM pcdsEmployee WHERE age NOT IN (17,16).

Data Marts are smaller section of Data Warehouses. They help data warehouses collect data. For example your company has lot of branches which are spanned across the globe. Head-office of the company decides to collect data from all these branches for anticipating market. So to achieve this IT department can setup data mart in all branch offices and a central data warehouse where all data will finally reside.

Below SQL selects employees born between ’01/01/1975′ AND ’01/01/1978′ as per mysql SELECT * FROM pcdsEmployee WHERE DOB BETWEEN ‘1975-01-01’ AND ‘2011-09-28’ Sure, the BETWEEN clause in a database management system (DBMS) is used to specify a range to test against. It’s commonly used in SQL queries to filter data within a specified range of values. Here’s how it works: sql SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2; column_name: The column you want to test against. table_name:…

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When we design transactional database we always think in terms of normalizing design to its least form. But when it comes to designing for Data warehouse we think more in terms of denormalizing the database. Data warehousing databases are designed using Dimensional Modeling. Dimensional Modeling uses the existing relational database structure and builds on that. There are two basic tables in dimensional modeling:- Fact Tables. Dimension Tables. Fact tables are central tables in data warehousing. Fact tables have the actual…

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