A SELECT query in MS SQL (Microsoft SQL Server) is used to retrieve data from a database. The basic syntax of a SELECT query is:

Here's a breakdown of each clause:

• SELECT: Specifies the columns you want to retrieve.
• FROM: Specifies the table from which to retrieve the data.
• WHERE: Filters the rows based on a specified condition.
• ORDER BY: Sorts the result set based on one or more columns.
• GROUP BY: Groups rows that have the same values into summary rows.
• HAVING: Filters groups based on a specified condition (used with GROUP BY).

Examples:

1. Basic Query: Retrieve all columns from a table named Employees.

   SELECT * FROM Employees;

2. Select Specific Columns: Retrieve only FirstName and LastName from the Employees table.

   SELECT FirstName, LastName FROM Employees;

3. With a Condition: Retrieve employees with a salary greater than 50,000.

   SELECT FirstName, LastName, Salary FROM Employees WHERE Salary > 50000;

4. Sorting Results: Retrieve all employees, sorted by LastName in ascending order.

   SELECT FirstName, LastName FROM Employees ORDER BY LastName ASC;

5. Grouping and Aggregating: Count the number of employees in each department.

   SELECT Department, COUNT(*) AS NumberOfEmployees FROM Employees GROUP BY Department;

6. Filtering Groups: Retrieve departments with more than 10 employees.

   SELECT Department, COUNT(*) AS NumberOfEmployees FROM Employees GROUP BY Department HAVING COUNT(*) > 10;