Part 08: Designing Tables, Data Types and Constraints
The article discusses the importance of designing tables, data types, and constraints in SQL databases. It emphasizes how these elements ensure data integrity and proper data handling. The author provides examples of common data types and constraints that can be applied to database columns.
- ▪A table definition in SQL is similar to a well-designed sign-up form, where each field has specific input types and validation rules.
- ▪Common data types include INTEGER for whole numbers, VARCHAR for text, and NUMERIC for exact decimal values, especially for money.
- ▪Constraints such as NOT NULL and UNIQUE help maintain data integrity by enforcing rules on the data entered into the database.
Opening excerpt (first ~120 words) tap to expand
try { if(localStorage) { let currentUser = localStorage.getItem('current_user'); if (currentUser) { currentUser = JSON.parse(currentUser); if (currentUser.id === 542036) { document.getElementById('article-show-container').classList.add('current-user-is-article-author'); } } } } catch (e) { console.error(e); } Mohamed Idris Posted on May 29 Part 08: Designing Tables, Data Types and Constraints #sql #database #learning Part of the "SQL: Zero to Ninja" series, for junior web devs who want SQL to finally click. Up to now, the tables already existed. You just queried them. But who decided that price holds numbers and email holds text? Who made sure two users can never share the same email? That was the person who designed the table. Today that person is you.
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