diff --git a/lib/group.js b/lib/group.js
index d29c823..6aec64d 100644
--- a/lib/group.js
+++ b/lib/group.js
@@ -36,6 +36,20 @@ class Group {
     )
   }
 
+  async put(args) {
+    if (!args.id) return false
+    const id = args.id
+    delete args.id
+    // Mysql.debug(1)
+    const r = await Mysql.update(
+      `UPDATE nt_group SET`,
+      `WHERE nt_group_id=${id}`,
+      Util.mapToDbColumn(args, groupDbMap),
+    )
+    // console.log(r)
+    return r.changedRows === 1
+  }
+
   async delete(args, val) {
     const g = await this.getAdmin(args)
     if (g.length !== 1) return false
diff --git a/lib/group.test.js b/lib/group.test.js
index 14abab2..0946f1d 100644
--- a/lib/group.test.js
+++ b/lib/group.test.js
@@ -24,6 +24,17 @@ describe('group', function () {
     })
   })
 
+  it('changes a group', async () => {
+    assert.ok(await group.put({ id: 4096, name: 'example.net' }))
+    assert.deepEqual(await group.get({ id: 4096 }), [
+      {
+        id: 4096,
+        name: 'example.net',
+      },
+    ])
+    assert.ok(await group.put({ id: 4096, name: 'example.com' }))
+  })
+
   it('delete a group', async () => {
     assert.ok(await group.delete({ id: 4096 }))
     let u = await group.getAdmin({ id: 4096 })
diff --git a/lib/mysql.js b/lib/mysql.js
index 35516b4..81d6e00 100644
--- a/lib/mysql.js
+++ b/lib/mysql.js
@@ -42,11 +42,19 @@ class MySQL {
   }
 
   async insert(query, params = {}) {
+    const skipExecute = params.skipExecute ?? false
+    delete params.skipExecute
+
     query += `(${Object.keys(params).join(',')}) VALUES(${Object.keys(params).map(() => '?')})`
+
+    if (skipExecute) return query
     return await this.execute(query, Object.values(params))
   }
 
   async select(query, params = {}) {
+    const skipExecute = params.skipExecute ?? false
+    delete params.skipExecute
+
     let paramsArray = []
     if (Array.isArray(params)) {
       paramsArray = [...params]
@@ -61,9 +69,20 @@ class MySQL {
       }
     }
 
+    if (skipExecute) return query
     return await this.execute(query, paramsArray)
   }
 
+  async update(query, where, params = {}) {
+    const skipExecute = params.skipExecute ?? false
+    delete params.skipExecute
+
+    query += ` ${Object.keys(params).join('=?,')}=? ${where}`
+
+    if (skipExecute) return { q: query, p: Object.values(params) }
+    return await this.execute(query, Object.values(params))
+  }
+
   async disconnect(dbh) {
     const d = dbh || this.dbh
     if (this._debug)
diff --git a/lib/mysql.test.js b/lib/mysql.test.js
index 3edebe2..6ff9186 100644
--- a/lib/mysql.test.js
+++ b/lib/mysql.test.js
@@ -18,9 +18,58 @@ describe('mysql', () => {
     })
   }
 
-  it.todo('SQL: formats SELECT queries', async () => {})
+  it('SQL: formats SELECT queries', async () => {
+    const r = await mysql.select(`SELECT * FROM nt_user WHERE`, {
+      last_name: 'Test',
+      skipExecute: true,
+    })
+    assert.equal(r, `SELECT * FROM nt_user WHERE last_name=?`)
+  })
+
+  it('SQL: formats INSERT queries', async () => {
+    const r = await mysql.select(`INSERT INTO nt_user SET`, {
+      first_name: 'uNite',
+      last_name: 'Test',
+      skipExecute: true,
+    })
+    assert.equal(r, `INSERT INTO nt_user SET first_name=? AND last_name=?`)
+  })
 
-  it.todo('SQL: formats INSERT queries', async () => {})
+  it('SQL: formats UPDATE queries, 1', async () => {
+    const { q, p } = await mysql.update(
+      `UPDATE nt_user SET`,
+      `WHERE nt_user_id=4096`,
+      { first_name: 'uNite', skipExecute: true },
+    )
+    assert.equal(q, `UPDATE nt_user SET first_name=? WHERE nt_user_id=4096`)
+    assert.deepEqual(p, ['uNite'])
+  })
+
+  it('SQL: formats UPDATE queries, 2', async () => {
+    const { q, p } = await mysql.update(
+      `UPDATE nt_user SET`,
+      `WHERE nt_user_id=4096`,
+      { last_name: 'Teste', is_admin: 1, skipExecute: true },
+    )
+    assert.equal(
+      q,
+      `UPDATE nt_user SET last_name=?,is_admin=? WHERE nt_user_id=4096`,
+    )
+    assert.deepEqual(p, ['Teste', 1])
+  })
+
+  it('SQL: formats UPDATE queries, 3', async () => {
+    const { q, p } = await mysql.update(
+      `UPDATE nt_user SET`,
+      `WHERE nt_user_id=4096`,
+      { first_name: 'Unit', last_name: 'Test', is_admin: 0, skipExecute: true },
+    )
+    assert.equal(
+      q,
+      `UPDATE nt_user SET first_name=?,last_name=?,is_admin=? WHERE nt_user_id=4096`,
+    )
+    assert.deepEqual(p, ['Unit', 'Test', 0])
+  })
 
   it('disconnects', async () => {
     assert.ok(this.dbh.connection.connectionId)
diff --git a/lib/user.js b/lib/user.js
index d0c7b3f..b0a7f9e 100644
--- a/lib/user.js
+++ b/lib/user.js
@@ -108,14 +108,26 @@ class User {
     )
   }
 
+  async put(args) {
+    if (!args.id) return false
+    const id = args.id
+    delete args.id
+    const r = await Mysql.update(
+      `UPDATE nt_user SET`,
+      `WHERE nt_user_id=${id}`,
+      Util.mapToDbColumn(args, userDbMap),
+    )
+    return r.changedRows === 1
+  }
+
   async delete(args, val) {
     const u = await this.getAdmin(args)
     if (u.length !== 1) return false
-    await Mysql.execute(`UPDATE nt_user SET deleted=? WHERE nt_user_id=?`, [
-      val ?? 1,
-      u[0].id,
-    ])
-    return true
+    const r = await Mysql.execute(
+      `UPDATE nt_user SET deleted=? WHERE nt_user_id=?`,
+      [val ?? 1, u[0].id],
+    )
+    return r.changedRows === 1
   }
 
   async destroy(args) {
diff --git a/lib/user.test.js b/lib/user.test.js
index 9e927e2..65d47f4 100644
--- a/lib/user.test.js
+++ b/lib/user.test.js
@@ -37,6 +37,10 @@ describe('user', function () {
       })
     })
 
+    it.todo('modifies existing user', async () => {
+      //
+    })
+
     it('deletes a user', async () => {
       assert.ok(await user.delete({ id: 4096 }))
       let u = await user.getAdmin({ id: 4096 })