Hope someone finds this well:

# Fixing D1 Local Persistence with Wrangler Pages Dev

## Issue

Local D1 persistence with `wrangler pages dev` may not work as expected, even when `preview_database_id` is set in `wrangler.toml` and `--persist-to` is used in the `dev` script. Runtime operations (e.g., API calls creating new data) might connect to a new, blank D1 instance instead of the schema-initialized, persisted one. This leads to "no such table" errors and data loss between development server restarts.

While `wrangler d1 execute --local ...` correctly applies the schema to the persisted file, Pages Functions at runtime might fail to use this persisted database.

## Solution

The fix involves making the D1 binding in the `wrangler pages dev` command more explicit by specifying both the binding name and the `database_name` from your `wrangler.toml`.

### 1. `wrangler.toml` Configuration

Ensure your D1 database configuration includes `preview_database_id`:

```toml
[[d1_databases]]
binding = "DB"                            # Binding used in Functions (e.g., context.env.DB)
database_name = "your-actual-db-name"     # The name of your D1 on Cloudflare
database_id = "your-remote-database-id"   # ID of your remote D1
preview_database_id = "your-db-preview"   # ID for the local persistent file
```

### 2. `package.json` `dev` script

Modify your `dev` script to use the `BINDING_NAME:DATABASE_NAME_FROM_TOML` format for the `--d1` flag.

**Original (potentially problematic for some setups):**
```json
{
  "scripts": {
    "dev": "wrangler pages dev <options> --d1=DB --persist-to=.wrangler/state"
  }
}
```

**Fixed (more explicit and reliable):**
```json
{
  "scripts": {
    "dev": "wrangler pages dev <options> --d1=DB:your-actual-db-name --persist-to=.wrangler/state"
  }
}
```
*(Replace `DB` with your specific binding name and `your-actual-db-name` with the `database_name` from your `wrangler.toml`.)*

This explicit linking helps ensure `wrangler pages dev` correctly uses the D1 configuration associated with the `preview_database_id` for runtime operations, enabling local persistence to function as intended. This has been observed as a fix with Wrangler v4.14.4 and v4.15.2.