Feature: support sql.NullString/sql.NullInt64 in Scan()

[bwish71]

Summary

gorqlite's Scan() supports custom nullable types (gorqlite.NullString, gorqlite.NullInt64, etc.) but does not support the standard library equivalents (sql.NullString, sql.NullInt64, sql.NullFloat64, sql.NullBool).

Attempting to scan into *sql.NullString returns:

unknown destination type (*sql.NullString) to scan into in variable #1

Motivation

Many Go codebases use database/sql nullable types as their standard pattern for handling NULL columns. When migrating to rqlite/gorqlite, users must rewrite all nullable field handling to use gorqlite-specific types or COALESCE workarounds. Supporting sql.Null* types natively would make gorqlite a drop-in replacement for more database/sql patterns.

Proposed Change

Add cases to the type switch in Scan() (query.go) for each sql.Null* type. For example:

case *sql.NullString:
    switch src := src.(type) {
    case string:
        *d = sql.NullString{Valid: true, String: src}
    case nil:
        *d = sql.NullString{Valid: false}
    default:
        return fmt.Errorf("invalid string col:%d type:%T val:%v", n, src, src)
    }

This would be ~30 lines of additions, fully backward-compatible, and follows the same pattern already used for gorqlite.NullString.

Types to add

• *sql.NullString
• *sql.NullInt64
• *sql.NullInt32
• *sql.NullInt16
• *sql.NullFloat64
• *sql.NullBool
• *sql.NullTime

Environment

• gorqlite commit: ac86a4a (2025-06-09)
• Go 1.21+

[otoolep]

This appears to be a AI-generated issue, which are known to find issues where none exist. Please provide example code using this library showing this issue occurring, or this issue may closed.