Val Town Code SearchReturn to Val Town

1# Database
2
3This app uses [Val Town SQLite](https://docs.val.town/std/sqlite/) to manage data. Every Val Town account comes with a free SQLite database, hosted on [Turso](https://turso.tech/). This folder is broken up into two files:
4
5* `migrations.ts` - code to set up the database tables the app needs
6* `queries.ts` - functions to run queries against those tables, which are imported and used in the main Hono server in `/backend/index.ts`
7
8## Migrations
9
10In `backend/database/migrations.ts`, this app creates a new SQLite table `reactHonoStarter_messages` to store messages. 
11
12This "migration" runs once on every app startup because it's imported in `index.ts`. You can comment this line out for a slight (30ms) performance improvement on cold starts. It's left in so that users who fork this project will have the migration run correctly.
13
14SQLite has much more limited support for altering existing tables as compared to other databases. Often it's easier to create new tables with the schema you want, and then copy the data over. Happily LLMs are quite good at those sort of database operations, but please reach out in the [Val Town Discord](https://discord.com/invite/dHv45uN5RY) if you need help.
15
16## Queries
17
18The queries file is where running the migrations happen in this app. It'd also be reasonable for that to happen in index.ts, or as is said above, for that line to be commented out, and only run when actual changes are made to your database schema.
19
20The queries file exports functions to get and write data. It relies on shared types and data imported from the `/shared` directory.

3import { createTables, tableName } from "./migrations.ts";
4
5// This will create the database table if it doesn't exist.
6// This will run every time the app starts up. You can
7// comment out this line for a modest (30ms) perforamnce improvement
8// on cold starts. It's left in to ensure the database tables are
9// automatically set up correctly for users who fork this app.
10await createTables();

13
14       However, you should know that SQLite has much more limited
15       support for altering existing tables as compared to other databases.
16       Often it's easier to create new tables with the schema you want, and then
17       copy the data over. */

1import { parseProject, readFile, serveFile } from "https://esm.town/v/std/utils/index.ts";
2import { Hono } from "npm:hono";
3import { getMessages, insertMessage } from "./database/queries.ts";
4
5const app = new Hono();

9export function calculateEstimatedDuration(steps: any[]): number {
10  const baseDuration = steps.length * 2;
11  const complexSteps = steps.filter(s => ["make_api_call", "database_operation"].includes(s.type)).length;
12  return baseDuration + (complexSteps * 5);
13}
38        permissions.add("network_access");
39        break;
40      case "database_operation":
41        permissions.add("database_access");
42        break;
43      case "collect_user_input":
63      dependencies.add("http_client");
64    }
65    if (step.type === "database_operation") {
66      dependencies.add("database_driver");
67    }
68  });

507                input: { label: "Entrada", icon: "📝", color: "#9C27B0", subtypes: ["Texto", "Número", "Arquivo", "Seleção"] },
508                output: { label: "Saída", icon: "📤", color: "#FF5722", subtypes: ["Exibir", "Arquivo", "Notificação", "Resposta API"] },
509                api: { label: "API", icon: "🌐", color: "#673AB7", subtypes: ["REST API", "GraphQL", "Webhook", "Database"] },
510                end: { label: "Fim", icon: "⏹️", color: "#F4436", subtypes: [] },
511            };

5function calculateEstimatedDuration(steps) {
6  const baseDuration = steps.length * 2;
7  const complexSteps = steps.filter(s => ["api_call", "database_operation"].includes(s.action)).length;
8  return baseDuration + (complexSteps * 5);
9}
24        permissions.add("network_access");
25        break;
26      case "database_operation":
27        permissions.add("database_access");
28        break;
29      case "collect_user_input":
44      dependencies.add("http_client");
45    }
46    if (step.action === "database_operation") {
47      dependencies.add("database_driver");
48    }
49  });

48| **Entrada** | 📝 | Coletar dados | Texto, Número, Arquivo, Seleção |
49| **Saída** | 📤 | Exibir resultados | Exibir, Arquivo, Notificação, Resposta API |
50| **API** | 🌐 | Chamadas externas | REST API, GraphQL, Webhook, Database |
51| **Fim** | ⏹️ | Ponto de término | - |
52
121- `display_output`: Exibição de resultados
122- `make_api_call`: Chamadas para APIs
123- `database_operation`: Operações de banco de dados
124- `iterate`: Loops e iterações
125- `terminate_agent`: Finalização do agente

32    'output': 'system_output',
33    'api': 'api_call',
34    'database': 'data_operation',
35    'loop': 'iteration'
36  };
127          break;
128
129        case 'database':
130          step.action = "database_operation";
131          step.parameters = {
132            operation: node.operation || "select",

507                input: { label: "Entrada", icon: "📝", color: "#9C27B0", subtypes: ["Texto", "Número", "Arquivo", "Seleção"] },
508                output: { label: "Saída", icon: "📤", color: "#FF5722", subtypes: ["Exibir", "Arquivo", "Notificação", "Resposta API"] },
509                api: { label: "API", icon: "🌐", color: "#673AB7", subtypes: ["REST API", "GraphQL", "Webhook", "Database"] },
510                end: { label: "Fim", icon: "⏹️", color: "#F4436", subtypes: [] },
511            };