Learning SQL: Part 1: Understanding Tables

Learning SQL

Structured Query Language (SQL) is a declarative programming language used for accessing data storied in relational databases. It appears in or is a core part of many common software packages like MySQL, PostgreSQL, Microsoft SQL Server, and Oracle Database.

Understanding Tables

In the rational database model, data is stored in tables

1DanSoftware Engineering
2ChadTechnical Writing

Tables are composed of rows, a set of data defined in reference to different columns. Serving as a way to define the data within itself, a column is frequently thought of as a header. These are common things like “Name”, “Company”, or “Project”. Columns serve as a description of one data entry in relation to others.

Rows, then, are data from multiple columns in one set. In relation to software like Microsoft Excel or Google Sheets, a row might be the numbered side. It would be something like Row 1 or Row 23 to describe a selection of data across multiple columns.

When working with SQL, data is handled in the rows requested. Through some expressions or comparisons, one or more rows are returned based on knowing at least one column name. To work with SQL is to understand data is stored in tables and how the rows and columns are arranged to describe the relationships between one entry to another.