How does this skill handle DuckDB queries?

It provides specific patterns for using the DuckDB ODBC driver to query Parquet files directly, including the recommended 60-second command timeout for large datasets.

Which C# database libraries does this skill cover?

It covers System.Data.Odbc for legacy and wide compatibility, Npgsql for native PostgreSQL access, and MySql.Data for MySQL integration.

Can I use this for legacy ERP systems?

Yes, it includes specific connection strings, table schemas, and permission fields for Sage1000, X3 (MS SQL Server), and Exportmaster (DBISAM).

What is the ExecuteAndMap pattern?

ExecuteAndMap is a specialized ODBC wrapper pattern that uses lambda mappers to provide type-safe object hydration, automatic connection disposal, and built-in null safety checks.

Why is explicit type casting mentioned for PostgreSQL?

PostgreSQL treats VARCHAR without a length differently than VARCHAR(n). The skill provides the specific syntax (e.g., ::VARCHAR(15)) required to prevent function signature mismatches in Npgsql.

C# Multi-Database Integration

Name: C# Multi-Database Integration
Author: lawless-m

bylawless-m

0•

Database Management

Provides standardized C# access patterns and best practices for interacting with DuckDB, PostgreSQL, MySQL, SQL Server, and DBISAM.

This skill acts as a comprehensive implementation guide for developers working with diverse database environments in .NET. It offers proven patterns for both modern high-performance drivers like Npgsql and legacy ODBC connections used by systems like Sage1000 and Exportmaster. By formalizing connection management, type-safe mapping via the ExecuteAndMap pattern, and specific workarounds for PostgreSQL type-casting and DuckDB Parquet queries, this skill ensures robust and maintainable data access layers across heterogeneous RDBMS platforms.

Key Features

01Standardized access patterns for DuckDB, PostgreSQL, MySQL, SQL Server, and DBISAM

02Type-safe result mapping using the ServiceLib ExecuteAndMap lambda pattern

03Optimized DuckDB configuration for direct Parquet file querying

040 GitHub stars

05Pre-defined schemas and query patterns for X3 and Sage1000 ERP systems

06Deep-dive guidance on PostgreSQL native array support and explicit type casting

Use Cases

01Implementing robust, null-safe database repositories with standardized connection handling

02Building data migration tools to extract legacy ERP data into modern Parquet-based analytics stores

03Developing high-performance .NET backends that require native PostgreSQL or MySQL integration

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add lawless-m/doctordot Databases

For use in Claude.ai and ChatGPT

Download Skill