Table · Database & SQL · Software Knowledge

01 · What is it?

A table is a structured collection of related records organized into rows and columns.

A table usually represents one entity or one category of related data. For example, a users table stores users, and an orders table stores orders.

Simple idea: one table keeps one kind of record in a predictable shape.

02 · Think of it like...

Think of a spreadsheet tab made for one kind of thing. The column headings name the details, and each horizontal line holds one complete record.

Table

The whole organized set of related records.

Row

One complete record, such as one user.

Column

One named kind of information, such as email.

Field value

The actual value at one row and one column.

In a Users table, Rebecca is a field value in the name column of one row.

03 · What does it do?

A database table defines how related records can be stored, checked, found, and connected.

Columns

Names describe what information each record can contain.

Data types

Rules say whether a value is text, a number, a date, or another type.

Keys & constraints

Keys identify or connect records, while constraints protect data quality.

Relationships

References can connect records in this table to records in another table.

04 · Where is it used?

Tables are used anywhere an application needs to manage many related records.

Users

One row for each account.

Customers

Contact details and preferences.

Orders

Purchases and their status.

Products

Names, prices, and stock details.

Inventory

Quantities available at each location.

05 · Example

Here is a real-looking users table. The header row names the columns. Each line below it is one row, or one user record.

Users
id	name	email	created_at
1	Rebecca	rebecca@example.com	2026-09-10
2	Alex	alex@example.com	2026-09-10

Read one cell: in the first row, Rebecca is the field value for the name column. The full row describes one user.

CREATE TABLE users (
  id INTEGER PRIMARY KEY,
  name TEXT NOT NULL,
  email TEXT NOT NULL UNIQUE,
  created_at DATE NOT NULL
);

This SQL defines the table’s columns, data types, primary key, and constraints. The stored rows then follow that shape.

06 · How it connects

Database

Table

Row + Column

Schema

Primary Key

Foreign Key

SQL

The database contains tables. A table contains rows and columns. Its schema defines the rules, keys connect the data, and SQL is used to work with it.

07 · Do Not Confuse

Table vs Database

A database can contain many tables. A table is one organized data structure inside it.

Table vs Schema

A table stores records. A schema describes the table’s columns, types, keys, and rules.

Table vs Row

A table is the collection. A row is one complete record in that collection.

Table vs Spreadsheet

They look similar, but a database table has database rules, keys, constraints, and relationships.

08 · Topic Glossary

ENGLISH TERM	中文	SIMPLE ENGLISH	中文小白理解
Table	数据表	A structured collection of related records.	把同一类数据按行和列组织起来的结构。
Database	数据库	A system that stores and manages related data.	用来保存和管理相关数据的系统。
Row	行	One complete record in a table.	表中代表一个对象或事件的一整条记录。
Column	列	One named type of information in every row.	每一行都按照同一种信息类别保存数据。
Field value	字段值	The actual value stored at one row and column.	某一行某一列里真正保存的内容。
Schema	模式 / 结构	The blueprint for a table’s columns and rules.	规定表有哪些列、数据类型和规则的蓝图。
Primary Key	主键	A value that uniquely identifies a row.	用来唯一标识一行数据的值。
Foreign Key	外键	A value that points to a row in another table.	指向另一张表中某一行的值，用来建立连接。
Constraint	约束	A rule that controls which data is allowed.	规定什么数据可以被保存的规则。
Relationship	关系	A connection between related records or tables.	相关记录或数据表之间的关联。
SQL	结构化查询语言	A language used to work with relational data.	用来查询和修改关系型数据库数据的语言。

09 · What to Remember

A table represents one entity or category of related data.

Rows are records, columns describe the records, and each cell holds a field value.

A table’s schema, keys, constraints, and relationships help keep data useful and connected.