SQL Server Fundamentals: Understanding Rows and Columns

What Are Rows in SQL Server?

Rows are the individual records in a table. Each row contains data corresponding to each column in the table.

Continuing the 'Customers' example, each row would represent one customer with their specific details.

• Rows hold the actual data entries.
• Each row must have a value for every column, unless the column allows NULLs.
• Rows are uniquely identified by primary keys or unique constraints.

How Rows and Columns Work Together

Columns and rows together form the table structure and data. Columns define what data is stored, and rows hold the data instances.

This tabular format allows SQL Server to efficiently store, retrieve, and manipulate data.

• Columns define the data schema.
• Rows contain the data records.
• SQL queries operate by selecting, inserting, updating, or deleting rows based on column values.

Example: Creating and Querying a Table

Here is a simple example of creating a table with columns and inserting rows, followed by a query to retrieve data.