SkillCoded

SQL Fundamentals

Create Tables and Choose Column Types

Translate a small data model into PostgreSQL tables with meaningful column names, suitable types, stable keys, and enforceable constraints.

Beginner14 min read
SQL Fundamentals lessonRelational data foundationsPractice

UNTIMED COACHING

Practice before the pressure

Use feedback to correct the model, not merely memorize an option position.

GUIDED PRACTICE

Practice the lesson questions

Answer normal lesson questions without a timer. Every answer includes an explanation, and incorrect answers can be tried again before continuing.

CONCEPT MODELS

See the lesson as a system

Use these visual guides to connect the key ideas before answering the questions.

Connect the roles in Create Tables and Choose Column TypesKeep table definition, column type, primary key, and column constraint as separate roles.
Connect the roles in Create Tables and Choose Column TypesA topic-specific model connects four distinct roles used to reason about create tables and choose column types.
Table recordTable represents repair shop devices
Column valueData type matches field meaning
Primary key valueValue identifies one device row
Constraint decisionDecision protects accepted column values
Verify Schema inspectionConnect schema inspection with its topic-specific inspection, expected outcome, and protected database boundary.
Verify Schema inspectionA verification model for create tables and choose column types connects the final data decision to its check, result, and protected boundary.
Schema inspectionCheck displays the declared table
Starting checkReview starting check
Expected resultConfirm starting check
Safety boundaryProtect table record scope