KDBC — Unified C Database Connectivity

A lightweight C11 library that provides a single API for multiple database backends. Libraries are loaded at runtime via dlopen, so missing backends are handled gracefully — only the drivers you actually use need to be installed.

Supported Databases

Database	Driver	Native Library
SQLite	KDBC_SQLITE	libsqlite3
PostgreSQL	KDBC_POSTGRES	libpq
MariaDB / MySQL	KDBC_MARIADB	libmariadb
Oracle	KDBC_ORACLE	ODPI-C
MS SQL Server	KDBC_MSSQL	FreeTDS

Quick Example

#include "kdbc.h"
#include <stdio.h>
 
int main(void) {
    kdbc_conn *conn = kdbc_connect(KDBC_SQLITE, ":memory:", NULL, NULL);
 
    kdbc_execute_update(conn,
        "CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
 
    kdbc_stmt *stmt = kdbc_prepare(conn, "INSERT INTO users (name) VALUES (?)");
    kdbc_bind_string(stmt, 1, "Alice");
    kdbc_execute_update_stmt(stmt);
    kdbc_stmt_close(stmt);
 
    kdbc_result *rs = kdbc_execute_query(conn, "SELECT id, name FROM users");
    while (kdbc_next(rs) == 1)
        printf("%lld: %s\n", (long long)kdbc_get_long(rs, 1), kdbc_get_string(rs, 2));
    kdbc_result_close(rs);
 
    kdbc_close(conn);
}

Key Design Points

• Opaque handles: kdbc_conn, kdbc_stmt, kdbc_result
• Runtime driver loading: no link-time dependency on any database client
• JDBC-style ? placeholders: auto-translated to $1 (PostgreSQL), :1 (Oracle), or native ?
• 1-indexed column and parameter indices
• Per-handle error buffers with thread-local global fallback

API Groups

Browse the API by section using the navigation on the left, or see the complete reference for kdbc.h.