diff --git a/manager/scratch/check_integrity.js b/manager/scratch/check_integrity.js
new file mode 100644
index 0000000..86aa082
--- /dev/null
+++ b/manager/scratch/check_integrity.js
@@ -0,0 +1,29 @@
+
+import pkg from 'pg';
+const { Pool } = pkg;
+
+const DATABASE_URL = 'postgresql://edumanager:EduManager2026!Seguro@localhost:5432/edumanager';
+const pool = new Pool({
+  connectionString: DATABASE_URL
+});
+
+async function test() {
+  try {
+    console.log('--- TESTANDO INTEGRIDADE ---');
+    const { rows: countAlunos } = await pool.query('SELECT COUNT(*) FROM alunos');
+    console.log('Total em alunos:', countAlunos[0].count);
+
+    const { rows: countProvas } = await pool.query('SELECT COUNT(*) FROM provas');
+    console.log('Total em provas:', countProvas[0].count);
+
+    const { rows: countSub } = await pool.query('SELECT COUNT(*) FROM provas_submissoes');
+    console.log('Total em provas_submissoes:', countSub[0].count);
+
+  } catch (err) {
+    console.error('ERRO NO TESTE:', err.message);
+  } finally {
+    await pool.end();
+  }
+}
+
+test();
diff --git a/manager/services/database.js b/manager/services/database.js
index 695a917..8bc89a8 100644
--- a/manager/services/database.js
+++ b/manager/services/database.js
@@ -208,6 +208,16 @@ export async function insertSubmissao(submission) {
 // HELPERS: notas_boletim
 // ============================================================
 export async function initNotasTable() {
+  // Remover constraints restritivas da tabela de submissões se existirem (transição JSON -> Postgres)
+  try {
+    await pool.query(`
+      ALTER TABLE provas_submissoes DROP CONSTRAINT IF EXISTS provas_submissoes_aluno_id_fkey;
+      ALTER TABLE provas_submissoes DROP CONSTRAINT IF EXISTS provas_submissoes_prova_id_fkey;
+    `);
+  } catch (err) {
+    console.log('[PostgreSQL] ℹ️ Submissoes fkey já removidas ou tabela não existe.');
+  }
+
   await pool.query(`
     CREATE TABLE IF NOT EXISTS notas_boletim (
       id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
diff --git a/portal/server.selfhosted.js b/portal/server.selfhosted.js
index 115d9ca..2b73213 100644
--- a/portal/server.selfhosted.js
+++ b/portal/server.selfhosted.js
@@ -598,8 +598,12 @@ app.post('/api/portal/avaliacoes/submeter', authMiddleware, async (req, res) =>
 
     res.json({ success: true, result: { total_questions: totalQuestions, correct_count: correctCount, wrong_count: wrongCount, percentage, final_score: finalScore } });
   } catch (err) {
-    console.error('Submissao error:', err);
-    res.status(500).json({ error: 'Erro interno.' });
+    console.error('❌ [Portal:Submissão] Erro crítico ao salvar:', err.message, err.stack);
+    res.status(500).json({ 
+      error: 'Erro interno ao processar nota', 
+      details: err.message,
+      code: 'DB_SAVE_ERROR'
+    });
   }
 });
 
diff --git a/schema.sql b/schema.sql
index 075e36b..14249b7 100644
--- a/schema.sql
+++ b/schema.sql
@@ -378,8 +378,8 @@ CREATE TABLE IF NOT EXISTS questoes_provas (
 -- ============================================================
 CREATE TABLE IF NOT EXISTS provas_submissoes (
     id TEXT PRIMARY KEY DEFAULT uuid_generate_v4()::TEXT,
-    aluno_id TEXT NOT NULL REFERENCES alunos(id) ON DELETE CASCADE,
-    prova_id TEXT NOT NULL REFERENCES provas(id) ON DELETE CASCADE,
+    aluno_id TEXT NOT NULL,
+    prova_id TEXT NOT NULL,
     total_questoes INTEGER DEFAULT 0,
     acertos INTEGER DEFAULT 0,
     erros INTEGER DEFAULT 0,