backend/db/migrations/20260615000001_create_conversations_table.cjs

exports.up = function (knex) {
  return knex.schema
    .createTable("conversations", (t) => {
      t.increments("Id");
      t.integer("UsuarioId").unsigned().notNullable();
      t.string("Title", 255).notNullable().defaultTo("Nova conversa");
      t.timestamp("CreatedAt").notNullable().defaultTo(knex.fn.now());
      t.timestamp("UpdatedAt").notNullable().defaultTo(knex.fn.now());

      t.foreign("UsuarioId").references("usuarios.Id").onDelete("CASCADE");
      t.index(["UsuarioId"]);
      t.index(["UpdatedAt"]);
    })
    .createTable("messages", (t) => {
      t.increments("Id");
      t.integer("ConversationId").unsigned().notNullable();
      t.string("Role", 10).notNullable();
      t.text("Content").notNullable();
      t.json("Sources").nullable();
      t.timestamp("SentAt").notNullable().defaultTo(knex.fn.now());

      t.foreign("ConversationId").references("conversations.Id").onDelete("CASCADE");
      t.index(["ConversationId"]);
    });
};

exports.down = function (knex) {
  return knex.schema.dropTable("messages").dropTable("conversations");
};