[CS] Frequently Used SQL syntax

Q. What SQL statement is used to retrieve data from a database?

A. The SELECT statement is used to fetch data from one or more tables in a database.

SELECT * FROM table_name;

Q. How do you insert new data into a table named customers with columns name and email?

A. Use the INSERT INTO statement to add new records to a table.

INSERT INTO customers (name, email)
VALUES ('John Doe', 'john@example.com');

Q. What SQL keyword is used to modify existing data in a table?

A. The UPDATE statement is used to modify existing records in a table based on specified conditions.

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

Essential SQL Syntax Patterns for Everyday Use

SQL (Structured Query Language) is essential for managing and manipulating data in relational databases. Mastering fundamental SQL syntax patterns empowers developers and analysts to efficiently retrieve, manipulate, and organize data.

Creating an Index

Indexes enhance query performance by providing quick access to rows in a table. Use the following syntax to create an index.

CREATE INDEX index_name
ON table_name (column_name);

Updating Data with Conditions

Update specific rows in a table based on certain conditions using UPDATE with SET and WHERE clauses.

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

Joining Data from Multiple Tables

Combine data from different tables using various join types.

Inner Join retrieves rows with matching values in both tables.

SELECT columns
FROM table1
INNER JOIN table2 ON table1.column_name = table2.column_name;

Left Join retrieves all rows from the left table and matching rows from the right table

SELECT columns
FROM table1
LEFT JOIN table2 ON table1.column_name = table2.column_name;

Right Join retrieves all rows from the right table and matching rows from the left table.

SELECT columns
FROM table1
RIGHT JOIN table2 ON table1.column_name = table2.column_name;

Full Outer Join retrieves all rows when there is a match in either table.

SELECT columns
FROM table1
FULL OUTER JOIN table2 ON table1.column_name = table2.column_name;

Inserting Data into a Table

Add new rows of data into a table using INSERT INTO.

INSERT INTO table_name (column1, column2, ...)
VALUES (value1, value2, ...);

Creating a View

Views are virtual tables derived from one or more base tables. Use CREATE VIEW AS to define a view.

CREATE VIEW view_name AS
SELECT columns
FROM table_name
WHERE condition;

Altering Table Structure

Modify the structure of a table using ALTER TABLE.

Adding Columns.

ALTER TABLE table_name
ADD column_name datatype;

Ordering Results

Sort query results in ascending or descending order using ORDER BY.

SELECT columns
FROM table_name
ORDER BY column_name ASC|DESC;

Calculating Rankings

To rank rows based on certain criteria, such as scores or sales.

SELECT column1, column2, ..., RANK() OVER (ORDER BY score DESC) AS rank
FROM table_name;

This query ranks rows based on the score column in descending order. This format should be more suitable for your blog post, providing both SQL code examples and their explanations.