SQL CREATE TABLE statement
Here is a clear, complete, and practical guide to the SQL CREATE TABLE statement, with examples for MySQL, PostgreSQL, SQL Server, and Oracle.
✅ What SQL CREATE TABLE statement Does
CREATE TABLE creates a new table in a database with defined:
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Columns
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Data types
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Constraints (PRIMARY KEY, FOREIGN KEY, UNIQUE, etc.)
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Default values
🔹 Basic ANSI SQL Syntax
📌 Simple Example
🔥 Example With Constraints
🔗 Example With FOREIGN KEY
🟦 MySQL — CREATE TABLE Example
🟪 PostgreSQL — CREATE TABLE Example
🟧 SQL Server — CREATE TABLE Example
🟨 Oracle — CREATE TABLE Example
🔥 Add a CHECK Constraint
🧩 Common SQL Data Types
| Type | Description |
|---|---|
| INT / BIGINT | Whole numbers |
| VARCHAR(n) | Text up to n chars |
| TEXT | Long text |
| DATE | Date only |
| TIMESTAMP / DATETIME | Date + time |
| DECIMAL(p,s) | Precise numbers (money) |
| BOOLEAN | True/false |
| SERIAL (PostgreSQL) | Auto-increment integer |
| AUTO_INCREMENT (MySQL) | Auto-increment integer |
| IDENTITY (SQL Server) | Auto-increment integer |
🧠 Best Practices
✔ Always define a PRIMARY KEY
✔ Use meaningful column names
✔ Use appropriate data types (especially for money: DECIMAL)
✔ Use NOT NULL where required
✔ Add indexes for frequent search columns
✔ Use foreign keys to maintain data integrity
✔ Use snake_case or lower_case naming conventions
✔ Avoid unnecessary large text fields (TEXT, LONGTEXT)
