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Recap of SQL Fundamentals

Recap of SQL Fundamentals

After traversing through the journey of SQL, we have covered many fundamental concepts that are crucial for data manipulation and analysis. Let's take a moment to recap what we've learned so far:

SQL Basics​

SQL stands for Structured Query Language and it's used to communicate with databases. It is the standard language for relational database management systems.

Data Definition Language (DDL)​

We learned about DDL commands like CREATE, ALTER, DROP, and TRUNCATE. These commands help us create, modify, delete, or truncate databases and tables.

Data Manipulation Language (DML)​

We also discussed DML commands, such as SELECT, INSERT, UPDATE, and DELETE. These commands allow us to select, insert, update, and delete data from a database.

SQL Operators​

We discussed the various SQL operators, like Arithmetic, Comparison, and Logical operators, which can be used to perform operations on data.

SQL Functions​

SQL functions were also introduced. We learned about aggregate functions like COUNT, SUM, AVG, MAX, and MIN, and scalar functions like UCASE, LCASE, MID, LEN, ROUND, NOW, and FORMAT.

SQL Clauses​

We also explored SQL clauses including WHERE, GROUP BY, HAVING, ORDER BY, and JOIN. These clauses help us filter, group, and order our data, and also combine rows from two or more tables based on a related column.

SQL Data Types​

We took a deep dive into SQL data types. We learned about various data types like CHAR, VARCHAR, INT, FLOAT, DATE, and others that help us define the type of data that can be stored in a particular column of a table.

SQL Constraints​

Finally, we learned about SQL constraints including NOT NULL, UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK, and DEFAULT. These constraints are used to specify rules for the data in a table.

Next Steps​

Having covered these fundamental topics, you are now well-equipped to start working with SQL databases. You should practice writing SQL queries and try to apply what you've learned in real-world scenarios.

Remember, learning SQL is not just about memorizing commands and syntax. It's about understanding how to manipulate and retrieve data in the most efficient way. So keep practicing, stay curious, and don't be afraid to experiment and learn from your mistakes.

Happy querying!