SQLite to PostgreSQL Converter - Free Online Tool 2025

Moving from SQLite to PostgreSQL unlocks scalable database features, sophisticated querying, and enterprise-grade reliability. Yet, manual migration introduces headaches: data type mismatches, subtle syntax differences, and compatibility issues in everyday SQL tasks. Developers often spend hours rewriting queries, fixing failed imports, or debugging schema problems. AI2sql offers a smarter solution—simply describe your intended operation in plain English and instantly generate PostgreSQL-compliant SQL. No more guesswork, no more tedious syntax fixes—just quick, accurate results that accelerate your migration project.

SQLite to PostgreSQL Migration Overview

Upgrading from SQLite—a lightweight, file-based database—to PostgreSQL, a powerful, open-source RDBMS, is a common modernization step. PostgreSQL supports concurrent users, advanced indexing, and full transaction logging, making it ideal for larger-scale applications. However, SQL syntax, data types, and underlying engine capabilities differ between the databases, which can complicate direct migrations. A structured approach simplifies the move and reduces downtime or data loss risks.

Key Syntax Differences: SQLite vs PostgreSQL

Data Type Mapping Guide

• INTEGER in SQLite → INTEGER or BIGINT in PostgreSQL

• TEXT → TEXT or VARCHAR

• REAL → DOUBLE PRECISION or REAL

• BLOB → BYTEA

• DATETIME or DATE as TEXT → TIMESTAMP or DATE

• BOOLEAN (INTEGER 0/1) → BOOLEAN

Common Conversion Challenges

• Auto-increment Fields: SQLite uses AUTOINCREMENT with INTEGER, PostgreSQL uses SERIAL or IDENTITY columns.

• Type Affinity: SQLite is type-flexible; PostgreSQL enforces strict type usage.

• Function Naming: Date and string functions differ in name and arguments between platforms.

• Foreign Key Constraints: Sometimes disabled in SQLite; enforced by default in PostgreSQL.

• NULL Handling: Behaviors differ in unique constraints and defaults.

Step-by-Step Migration Process

1. Analyze your SQLite schema: Extract tables, indexes, triggers, and data types.

2. Map data types: Adjust column types for PostgreSQL compatibility.

3. Transform schema: Rewrite CREATE TABLE, CONSTRAINTS, and indexed statements.

4. Export data: Dump your SQLite database (using .dump or export tools).

5. Convert SQL scripts: Update syntax for PostgreSQL requirements; pay special attention to AUTOINCREMENT, default values, and UNIQUE handling.

6. Import to PostgreSQL: Use psql CLI, GUI tools, or AI2sql-generated queries to load and validate migrated data.

7. Test and verify: Compare record counts and perform data validation to catch conversion errors.

AI2sql: Generate PostgreSQL Queries from Natural Language

Manual rewriting of SQL for PostgreSQL is tedious and error-prone, especially for complex business logic or large schemas. AI2sql platform automates this step: input a natural-language description—like "Show total sales for this month grouped by region"—and instantly receive production-ready PostgreSQL syntax. This AI-powered workflow eliminates conversion mistakes, speeds up onboarding to new databases, and requires zero syntax memorization.

SQLite vs PostgreSQL Conversion Examples

More Practical Conversion Examples

1. Foreign Key Constraints:
   

2. Change Data Type from TEXT to TIMESTAMP:
   

3. Retrieve Last Inserted ID:
   

4. Define Unique Index:
   

5. Function Translation (String Length):
   

Skip manual conversion - Generate PostgreSQL queries instantly with AI2sql using natural language.

Troubleshooting: Common Conversion Errors

• Data type mismatch: Convert date/time TEXT columns to TIMESTAMP before importing.

• Reserved words: Quote PostgreSQL reserved keywords (e.g., user, order) with double quotes.

• Missing SERIAL type: Replace AUTOINCREMENT with SERIAL for auto-incrementing fields.

• Boolean conversion: Convert INTEGER(1/0) to BOOLEAN (TRUE/FALSE) in schema and data.

Performance Tips for PostgreSQL Optimization

• Define indexes for heavy read queries and common JOIN operations.

• Use native data types for efficiency (e.g., BOOLEAN, TIMESTAMP).

• Avoid SELECT * in production; specify columns for faster response times.

• Analyze and VACUUM tables post-migration to update statistics.

Conclusion: Streamline SQLite to PostgreSQL Migration with AI2sql

Transitioning from SQLite to PostgreSQL delivers scalability and advanced SQL features for your applications, but conversion can be tricky—from syntax mismatches to data type changes. AI2sql erases the hassle: generate accurate, production-ready PostgreSQL queries from plain English in seconds. Whether you’re modernizing legacy apps or scaling up, AI2sql saves time, cuts errors, and builds confidence with every migration. Try AI2sql Free - Generate PostgreSQL Queries from Plain English.

• Try AI2sql PostgreSQL Generator

• PostgreSQL SQL Tutorial

• SQLite Migration Tools