diff --git a/php/src/db/Capacitor.php b/php/src/db/Capacitor.php
index 6177bc4..743cfd7 100644
--- a/php/src/db/Capacitor.php
+++ b/php/src/db/Capacitor.php
@@ -34,16 +34,20 @@ class Capacitor {
     return $this->storage->_charge($this->channel, $item, $func, $args);
   }
 
+  function discharge($filter=null, ?bool $reset=null): iterable {
+    return $this->storage->_discharge($this->channel, $reset);
+  }
+
   function count($filter=null): int {
     return $this->storage->_count($this->channel, $filter);
   }
 
-  function discharge($filter=null, ?bool $reset=null): iterable {
-    return $this->storage->_discharge($this->channel, $filter, $reset);
+  function one($filter): ?array {
+    return $this->storage->_one($this->channel, $filter);
   }
 
-  function get($filter) {
-    return $this->storage->_get($this->channel, $filter);
+  function all($filter): iterable {
+    return $this->storage->_all($this->channel, $filter);
   }
 
   function each($filter, ?callable $func=null, ?array $args=null): int {
diff --git a/php/src/db/CapacitorChannel.php b/php/src/db/CapacitorChannel.php
index b14308c..82620a3 100644
--- a/php/src/db/CapacitorChannel.php
+++ b/php/src/db/CapacitorChannel.php
@@ -56,9 +56,17 @@ class CapacitorChannel {
    * retourner un ensemble de définitions pour des colonnes supplémentaires à
    * insérer lors du chargement d'une valeur
    *
-   * la colonne "_id" de définition "integer primary key autoincrement" est la
-   * clé primaire par défaut. elle peut être redéfinie, et dans ce cas la valeur
-   * à utiliser doit être retournée par {@link getKeyValues()}
+   * la clé primaire "id_" a pour définition "integer primary key autoincrement".
+   * elle peut être redéfinie, et dans ce cas la valeur à utiliser doit être
+   * retournée par {@link getKeyValues()}
+   *
+   * la colonne "item__" contient la valeur sérialisée de l'élément chargé. bien
+   * que ce soit possible techniquement, cette colonne n'a pas à être redéfinie
+   *
+   * les colonnes dont le nom se termine par "_" sont réservées.
+   * les colonnes dont le nom se termine par "__" sont automatiquement sérialisées
+   * lors de l'insertion dans la base de données, et automatiquement désérialisées
+   * avant d'être retournées à l'utilisateur (sans le suffixe "__")
    */
   function getKeyDefinitions(): ?array {
     return null;
@@ -68,28 +76,38 @@ class CapacitorChannel {
    * calculer les valeurs des colonnes supplémentaires à insérer pour le
    * chargement de $item
    *
-   * Si "_id" est retourné, la ligne existante est mise à jour le cas échéant.
+   * Cette méthode est utilisée par {@link Capacitor::charge()}. Si une valeur
+   * "id_" est retourné, la ligne correspondate existante est mise à jour
    */
   function getKeyValues($item): ?array {
     return null;
   }
 
+  /**
+   * Avant d'utiliser un id pour rechercher dans la base de donnée, corriger sa
+   * valeur le cas échéant.
+   */
+  function verifixId(string &$id): void {
+  }
+
   /**
    * méthode appelée lors du chargement d'un élément avec
    * {@link Capacitor::charge()}
    *
    * @param mixed $item l'élément à charger
-   * @param array $values les valeurs calculées par {@link getKeyValues()}
+   * @param array $updates les valeurs calculées par {@link getKeyValues()}
    * @param ?array $row la ligne à mettre à jour. vaut null s'il faut insérer
    * une nouvelle ligne
-   * @return ?array le cas échéant, un tableau non null à marger dans $values et
-   * utiliser pour provisionner la ligne nouvelle créée, ou mettre à jour la
-   * ligne existante
+   * @return ?array le cas échéant, un tableau non null à merger dans $updates
+   * et utilisé pour provisionner la ligne nouvellement créée, ou mettre à jour
+   * la ligne existante
    *
    * Si $item est modifié dans cette méthode, il est possible de le retourner
-   * avec la clé "_item" pour mettre à jour la ligne correspondante
+   * avec la clé "item" pour mettre à jour la ligne correspondante.
+   * La colonne "id_" ne peut pas être modifiée: si "id_" est retourné, il est
+   * ignoré
    */
-  function onCharge($item, array $values, ?array $row): ?array {
+  function onCharge($item, array $updates, ?array $row): ?array {
     return null;
   }
 
@@ -98,12 +116,14 @@ class CapacitorChannel {
    * {@link Capacitor::each()}
    *
    * @param mixed $item l'élément courant
-   * @param ?array $row la ligne à mettre à jour
+   * @param ?array $row la ligne à mettre à jour.
    * @return ?array le cas échéant, un tableau non null utilisé pour mettre à
    * jour la ligne courante
    *
    * Si $item est modifié dans cette méthode, il est possible de le retourner
-   * avec la clé "_item" pour mettre à jour la ligne correspondante
+   * avec la clé "item" pour mettre à jour la ligne correspondante
+   * La colonne "id_" ne peut pas être modifiée: si "id_" est retourné, il est
+   * ignoré
    */
   function onEach($item, array $row): ?array {
     return null;
diff --git a/php/src/db/CapacitorStorage.php b/php/src/db/CapacitorStorage.php
index ed71dbd..110cb29 100644
--- a/php/src/db/CapacitorStorage.php
+++ b/php/src/db/CapacitorStorage.php
@@ -1,6 +1,9 @@
 <?php
 namespace nulib\db;
 
+use nulib\cl;
+use nulib\php\func;
+
 /**
  * Class CapacitorStorage: objet permettant d'accumuler des données pour les
  * réutiliser plus tard
@@ -47,6 +50,13 @@ abstract class CapacitorStorage {
     return $this->_charge($this->getChannel($channel), $item, $func, $args);
   }
 
+  abstract function _discharge(CapacitorChannel $channel, bool $reset=true): iterable;
+
+  /** décharger les données du canal spécifié */
+  function discharge(?string $channel, bool $reset=true): iterable {
+    return $this->_discharge($this->getChannel($channel), $reset);
+  }
+
   abstract function _count(CapacitorChannel $channel, $filter): int;
 
   /** indiquer le nombre d'éléments du canal spécifié */
@@ -54,22 +64,26 @@ abstract class CapacitorStorage {
     return $this->_count($this->getChannel($channel), $filter);
   }
 
-  abstract function _discharge(CapacitorChannel $channel, $filter, ?bool $reset): iterable;
-
-  /** décharger les données du canal spécifié */
-  function discharge(?string $channel, $filter=null, ?bool $reset=null): iterable {
-    return $this->_discharge($this->getChannel($channel), $filter, $reset);
-  }
-
-  abstract function _get(CapacitorChannel $channel, $filter);
+  abstract function _one(CapacitorChannel $channel, $filter): ?array;
 
   /**
-   * obtenir l'élément identifié par les clés spécifiées sur le canal spécifié
+   * obtenir la ligne correspondant au filtre sur le canal spécifié
    *
-   * si $filter n'est pas un tableau, il est transformé en ["_id" => $filter]
+   * si $filter n'est pas un tableau, il est transformé en ["id_" => $filter]
    */
-  function get(?string $channel, $filter) {
-    return $this->_get($this->getChannel($channel), $filter);
+  function one(?string $channel, $filter): ?array {
+    return $this->_one($this->getChannel($channel), $filter);
+  }
+
+  abstract function _all(CapacitorChannel $channel, $filter): iterable;
+
+  /**
+   * obtenir les lignes correspondant au filtre sur le canal spécifié
+   *
+   * si $filter n'est pas un tableau, il est transformé en ["id_" => $filter]
+   */
+  function all(?string $channel, $filter): iterable {
+    return $this->_one($this->getChannel($channel), $filter);
   }
 
   abstract function _each(CapacitorChannel $channel, $filter, ?callable $func, ?array $args): int;
diff --git a/php/src/db/sqlite/SqliteCapacitor.php b/php/src/db/sqlite/SqliteCapacitor.php
deleted file mode 100644
index fed1b16..0000000
--- a/php/src/db/sqlite/SqliteCapacitor.php
+++ /dev/null
@@ -1,242 +0,0 @@
-<?php
-namespace nulib\db\sqlite;
-
-use nulib\cl;
-use nulib\db\CapacitorChannel;
-use nulib\db\CapacitorStorage;
-use nulib\php\func;
-use nulib\ValueException;
-
-/**
- * Class SqliteCapacitor
- */
-class SqliteCapacitor extends CapacitorStorage {
-  function __construct($sqlite) {
-    $this->sqlite = Sqlite::with($sqlite);
-  }
-
-  /** @var Sqlite */
-  protected $sqlite;
-
-  function sqlite(): Sqlite {
-    return $this->sqlite;
-  }
-
-  protected function _create(CapacitorChannel $channel): void {
-    if (!$channel->isCreated()) {
-      $columns = cl::merge([
-        "_id" => "integer primary key autoincrement",
-        "_item" => "text",
-        "_sum" => "varchar(40)",
-        "_created" => "datetime",
-        "_modified" => "datetime",
-      ], $channel->getKeyDefinitions());
-      $this->sqlite->exec([
-        "create table if not exists",
-        "table" => $channel->getTableName(),
-        "cols" => $columns,
-      ]);
-      $channel->setCreated();
-    }
-  }
-
-  /** @var CapacitorChannel[] */
-  protected $channels;
-
-  function addChannel(CapacitorChannel $channel): CapacitorChannel {
-    $this->_create($channel);
-    $this->channels[$channel->getName()] = $channel;
-    return $channel;
-  }
-
-  protected function getChannel(?string $name): CapacitorChannel {
-    $name = CapacitorChannel::verifix_name($name);
-    $channel = $this->channels[$name] ?? null;
-    if ($channel === null) {
-      $channel = $this->addChannel(new CapacitorChannel($name));
-    }
-    return $channel;
-  }
-
-  function _exists(CapacitorChannel $channel): bool {
-    $tableName = $this->sqlite->get([
-      "select name from sqlite_schema",
-      "where" => [
-        "name" => $channel->getTableName(),
-      ],
-    ]);
-    return $tableName !== null;
-  }
-
-  function _ensureExists(CapacitorChannel $channel): void {
-    $this->_create($channel);
-  }
-
-  function _reset(CapacitorChannel $channel): void {
-    $this->sqlite->exec([
-      "drop table if exists",
-      $channel->getTableName(),
-    ]);
-    $channel->setCreated(false);
-  }
-
-  function _charge(CapacitorChannel $channel, $item, ?callable $func, ?array $args): int {
-    $this->_create($channel);
-    $now = date("Y-m-d H:i:s");
-    $_item = serialize($item);
-    $_sum = sha1($_item);
-    $values = cl::merge([
-      "_item" => $_item,
-      "_sum" => $_sum,
-    ], $channel->getKeyValues($item));
-    $row = null;
-    $id = $values["_id"] ?? null;
-    if ($id !== null) {
-      # modification
-      $row = $this->sqlite->one([
-        "select _item, _sum, _created, _modified",
-        "from" => $channel->getTableName(),
-        "where" => ["_id" => $id],
-      ]);
-    }
-    $insert = null;
-    if ($row === null) {
-      # création
-      $values = cl::merge($values, [
-        "_created" => $now,
-        "_modified" => $now,
-      ]);
-      $insert = true;
-    } elseif ($_sum !== $row["_sum"]) {
-      # modification
-      $values = cl::merge($values, [
-        "_modified" => $now,
-      ]);
-      $insert = false;
-    }
-
-    if ($func === null) $func = [$channel, "onCharge"];
-    $onCharge = func::_prepare($func);
-    $args ??= [];
-    $updates = func::_call($onCharge, [$item, $values, $row, ...$args]);
-    if (is_array($updates)) {
-      if (array_key_exists("_item", $updates)) {
-        $_item = serialize($updates["_item"]);
-        $updates["_item"] = $_item;
-        $updates["_sum"] = sha1($_item);
-        if (!array_key_exists("_modified", $updates)) {
-          $updates["_modified"] = $now;
-        }
-      }
-      $values = cl::merge($values, $updates);
-    }
-
-    if ($insert === null) {
-      # aucune modification
-      return 0;
-    } elseif ($insert) {
-      $this->sqlite->exec([
-        "insert",
-        "into" => $channel->getTableName(),
-        "values" => $values,
-      ]);
-    } else {
-      $this->sqlite->exec([
-        "update",
-        "table" => $channel->getTableName(),
-        "values" => $values,
-        "where" => ["_id" => $id],
-      ]);
-    }
-    return 1;
-  }
-
-  function _count(CapacitorChannel $channel, $filter): int {
-    if ($filter !== null && !is_array($filter)) $filter = ["_id" => $filter];
-    return $this->sqlite->get([
-      "select count(*)",
-      "from" => $channel->getTableName(),
-      "where" => $filter,
-    ]);
-  }
-
-  function _discharge(CapacitorChannel $channel, $filter, ?bool $reset): iterable {
-    if ($filter !== null && !is_array($filter)) $filter = ["_id" => $filter];
-    if ($reset === null) $reset = $filter === null;
-    $rows = $this->sqlite->all([
-      "select _item",
-      "from" => $channel->getTableName(),
-      "where" => $filter,
-    ]);
-    foreach ($rows as $row) {
-      $item = unserialize($row['_item']);
-      yield $item;
-    }
-    if ($reset) $this->_reset($channel);
-  }
-
-  function _get(CapacitorChannel $channel, $filter) {
-    if ($filter === null) throw ValueException::null("keys");
-    if (!is_array($filter)) $filter = ["_id" => $filter];
-    $row = $this->sqlite->one([
-      "select _item",
-      "from" => $channel->getTableName(),
-      "where" => $filter,
-    ]);
-    if ($row === null) return null;
-    else return unserialize($row["_item"]);
-  }
-
-  function _each(CapacitorChannel $channel, $filter, ?callable $func, ?array $args): int {
-    if ($func === null) $func = [$channel, "onEach"];
-    $onEach = func::_prepare($func);
-    if ($filter !== null && !is_array($filter)) $filter = ["_id" => $filter];
-    $sqlite = $this->sqlite;
-    $tableName = $channel->getTableName();
-    $commited = false;
-    $count = 0;
-    $sqlite->beginTransaction();
-    $commitThreshold = $channel->getEachCommitThreshold();
-    try {
-      $rows = $sqlite->all([
-        "select",
-        "from" => $tableName,
-        "where" => $filter,
-      ]);
-      $args ??= [];
-      foreach ($rows as $row) {
-        $item = unserialize($row['_item']);
-        $updates = func::_call($onEach, [$item, $row, ...$args]);
-        if (is_array($updates)) {
-          if (array_key_exists("_item", $updates)) {
-            $updates["_item"] = serialize($updates["_item"]);
-          }
-          $sqlite->exec([
-            "update",
-            "table" => $tableName,
-            "values" => $updates,
-            "where" => ["_id" => $row["_id"]],
-          ]);
-          if ($commitThreshold !== null) {
-            $commitThreshold--;
-            if ($commitThreshold == 0) {
-              $sqlite->commit();
-              $sqlite->beginTransaction();
-              $commitThreshold = $channel->getEachCommitThreshold();
-            }
-          }
-        }
-        $count++;
-      }
-      $sqlite->commit();
-      $commited = true;
-      return $count;
-    } finally {
-      if (!$commited) $sqlite->rollback();
-    }
-  }
-
-  function close(): void {
-    $this->sqlite->close();
-  }
-}
diff --git a/php/src/db/sqlite/SqliteStorage.php b/php/src/db/sqlite/SqliteStorage.php
new file mode 100644
index 0000000..ca23c88
--- /dev/null
+++ b/php/src/db/sqlite/SqliteStorage.php
@@ -0,0 +1,309 @@
+<?php
+namespace nulib\db\sqlite;
+
+use nulib\cl;
+use nulib\db\CapacitorChannel;
+use nulib\db\CapacitorStorage;
+use nulib\php\func;
+use nulib\str;
+use nulib\ValueException;
+
+/**
+ * Class SqliteStorage
+ */
+class SqliteStorage extends CapacitorStorage {
+  function __construct($sqlite) {
+    $this->sqlite = Sqlite::with($sqlite);
+  }
+
+  /** @var Sqlite */
+  protected $sqlite;
+
+  function sqlite(): Sqlite {
+    return $this->sqlite;
+  }
+
+  const KEY_DEFINITIONS = [
+    "id_" => "integer primary key autoincrement",
+    "item__" => "text",
+    "sum_" => "varchar(40)",
+    "created_" => "datetime",
+    "modified_" => "datetime",
+  ];
+
+  /** sérialiser les valeurs qui doivent l'être dans $values */
+  protected function serialize(CapacitorChannel $channel, ?array $values): ?array {
+    if ($values === null) return null;
+    $columns = cl::merge(self::KEY_DEFINITIONS, $channel->getKeyDefinitions());
+    $index = 0;
+    $row = [];
+    foreach (array_keys($columns) as $column) {
+      $key = $column;
+      if ($key === $index) {
+        $index++;
+        continue;
+      } elseif (str::del_suffix($key, "__")) {
+        if (!array_key_exists($key, $values)) continue;
+        $value = $values[$key];
+        if ($value !== null) $value = serialize($value);
+      } else {
+        if (!array_key_exists($key, $values)) continue;
+        $value = $values[$key];
+      }
+      $row[$column] = $value;
+    }
+    return $row;
+  }
+
+  /** désérialiser les valeurs qui doivent l'être dans $values */
+  protected function unserialize(CapacitorChannel $channel, ?array $row): ?array {
+    if ($row === null) return null;
+    $columns = cl::merge(self::KEY_DEFINITIONS, $channel->getKeyDefinitions());
+    $index = 0;
+    $values = [];
+    foreach (array_keys($columns) as $column) {
+      $key = $column;
+      if ($key === $index) {
+        $index++;
+        continue;
+      } elseif (!array_key_exists($column, $row)) {
+        continue;
+      } elseif (str::del_suffix($key, "__")) {
+        $value = $row[$column];
+        if ($value !== null) $value = unserialize($value);
+      } else {
+        $value = $row[$column];
+      }
+      $values[$key] = $value;
+    }
+    return $values;
+  }
+
+  protected function _create(CapacitorChannel $channel): void {
+    if (!$channel->isCreated()) {
+      $columns = cl::merge(self::KEY_DEFINITIONS, $channel->getKeyDefinitions());
+      $this->sqlite->exec([
+        "create table if not exists",
+        "table" => $channel->getTableName(),
+        "cols" => $columns,
+      ]);
+      $channel->setCreated();
+    }
+  }
+
+  /** @var CapacitorChannel[] */
+  protected $channels;
+
+  function addChannel(CapacitorChannel $channel): CapacitorChannel {
+    $this->_create($channel);
+    $this->channels[$channel->getName()] = $channel;
+    return $channel;
+  }
+
+  protected function getChannel(?string $name): CapacitorChannel {
+    $name = CapacitorChannel::verifix_name($name);
+    $channel = $this->channels[$name] ?? null;
+    if ($channel === null) {
+      $channel = $this->addChannel(new CapacitorChannel($name));
+    }
+    return $channel;
+  }
+
+  function _exists(CapacitorChannel $channel): bool {
+    $tableName = $this->sqlite->get([
+      "select name from sqlite_schema",
+      "where" => [
+        "name" => $channel->getTableName(),
+      ],
+    ]);
+    return $tableName !== null;
+  }
+
+  function _ensureExists(CapacitorChannel $channel): void {
+    $this->_create($channel);
+  }
+
+  function _reset(CapacitorChannel $channel): void {
+    $this->sqlite->exec([
+      "drop table if exists",
+      $channel->getTableName(),
+    ]);
+    $channel->setCreated(false);
+  }
+
+  function _charge(CapacitorChannel $channel, $item, ?callable $func, ?array $args): int {
+    $this->_create($channel);
+    $now = date("Y-m-d H:i:s");
+    $item__ = serialize($item);
+    $sum_ = sha1($item__);
+    $row = cl::merge([
+      "item__" => $item__,
+      "sum_" => $sum_,
+    ], $this->unserialize($channel, $channel->getKeyValues($item)));
+    $prow = null;
+    $id_ = $row["id_"] ?? null;
+    if ($id_ !== null) {
+      # modification
+      $prow = $this->sqlite->one([
+        "select id_, item__, sum_, created_, modified_",
+        "from" => $channel->getTableName(),
+        "where" => ["id_" => $id_],
+      ]);
+    }
+    $insert = null;
+    if ($prow === null) {
+      # création
+      $row = cl::merge($row, [
+        "created_" => $now,
+        "modified_" => $now,
+      ]);
+      $insert = true;
+    } elseif ($sum_ !== $prow["sum_"]) {
+      # modification
+      $row = cl::merge($row, [
+        "modified_" => $now,
+      ]);
+      $insert = false;
+    }
+
+    if ($func === null) $func = [$channel, "onCharge"];
+    $onCharge = func::_prepare($func);
+    $args ??= [];
+    $values = $this->unserialize($channel, $row);
+    $pvalues = $this->unserialize($channel, $prow);
+    $updates = func::_call($onCharge, [$item, $values, $pvalues, ...$args]);
+    if (is_array($updates)) {
+      $updates = $this->serialize($channel, $updates);
+      if (array_key_exists("item__", $updates)) {
+        # si item a été mis à jour, il faut mettre à jour sum_
+        $updates["sum_"] = sha1($updates["item__"]);
+        if (!array_key_exists("modified_", $updates)) {
+          $updates["modified_"] = $now;
+        }
+      }
+      $row = cl::merge($row, $updates);
+    }
+
+    if ($insert === null) {
+      # aucune modification
+      return 0;
+    } elseif ($insert) {
+      $this->sqlite->exec([
+        "insert",
+        "into" => $channel->getTableName(),
+        "values" => $row,
+      ]);
+    } else {
+      $this->sqlite->exec([
+        "update",
+        "table" => $channel->getTableName(),
+        "values" => $row,
+        "where" => ["id_" => $id_],
+      ]);
+    }
+    return 1;
+  }
+
+  function _discharge(CapacitorChannel $channel, bool $reset=true): iterable {
+    $rows = $this->sqlite->all([
+      "select item__",
+      "from" => $channel->getTableName(),
+    ]);
+    foreach ($rows as $row) {
+      yield unserialize($row['item__']);
+    }
+    if ($reset) $this->_reset($channel);
+  }
+
+  protected function verifixFilter(CapacitorChannel $channel, &$filter): void {
+    if ($filter !== null && !is_array($filter)) {
+      $id = $filter;
+      $channel->verifixId($id);
+      $filter = ["id_" => $id];
+    }
+    $filter = $this->serialize($channel, $filter);
+  }
+
+  function _count(CapacitorChannel $channel, $filter): int {
+    $this->verifixFilter($channel, $filter);
+    return $this->sqlite->get([
+      "select count(*)",
+      "from" => $channel->getTableName(),
+      "where" => $filter,
+    ]);
+  }
+
+  function _one(CapacitorChannel $channel, $filter): ?array {
+    if ($filter === null) throw ValueException::null("filter");
+    $this->verifixFilter($channel, $filter);
+    $row = $this->sqlite->one([
+      "select",
+      "from" => $channel->getTableName(),
+      "where" => $filter,
+    ]);
+    return $this->unserialize($channel, $row);
+  }
+
+  function _all(CapacitorChannel $channel, $filter): iterable {
+    $this->verifixFilter($channel, $filter);
+    $rows = $this->sqlite->all([
+      "select",
+      "from" => $channel->getTableName(),
+      "where" => $filter,
+    ]);
+    foreach ($rows as $row) {
+      yield $this->unserialize($channel, $row);
+    }
+  }
+
+  function _each(CapacitorChannel $channel, $filter, ?callable $func, ?array $args): int {
+    if ($func === null) $func = [$channel, "onEach"];
+    $onEach = func::_prepare($func);
+    $sqlite = $this->sqlite;
+    $tableName = $channel->getTableName();
+    $commited = false;
+    $count = 0;
+    $sqlite->beginTransaction();
+    $commitThreshold = $channel->getEachCommitThreshold();
+    try {
+      $args ??= [];
+      foreach ($this->_all($channel, $filter) as $row) {
+        $updates = func::_call($onEach, [$row["item"], $row, ...$args]);
+        if (is_array($updates)) {
+          $updates = $this->serialize($channel, $updates);
+          if (array_key_exists("item__", $updates)) {
+            # si item a été mis à jour, il faut mettre à jour sum_
+            $updates["sum_"] = sha1($updates["item__"]);
+            if (!array_key_exists("modified_", $updates)) {
+              $updates["modified_"] = date("Y-m-d H:i:s");
+            }
+          }
+          $sqlite->exec([
+            "update",
+            "table" => $tableName,
+            "values" => $updates,
+            "where" => ["id_" => $row["id_"]],
+          ]);
+          if ($commitThreshold !== null) {
+            $commitThreshold--;
+            if ($commitThreshold == 0) {
+              $sqlite->commit();
+              $sqlite->beginTransaction();
+              $commitThreshold = $channel->getEachCommitThreshold();
+            }
+          }
+        }
+        $count++;
+      }
+      $sqlite->commit();
+      $commited = true;
+      return $count;
+    } finally {
+      if (!$commited) $sqlite->rollback();
+    }
+  }
+
+  function close(): void {
+    $this->sqlite->close();
+  }
+}
diff --git a/php/src/db/sqlite/_query.php b/php/src/db/sqlite/_query.php
index 647cd6b..9f4f038 100644
--- a/php/src/db/sqlite/_query.php
+++ b/php/src/db/sqlite/_query.php
@@ -109,9 +109,12 @@ class _query {
             $value = $cond[$condkeys[$condkey]];
             $condkey++;
           }
-        } else {
+        } elseif ($cond !== null) {
           $op = "=";
           $value = $cond;
+        } else {
+          $op = "is null";
+          $value = null;
         }
         $cond = [$key, $op];
         if ($value !== null) {
diff --git a/php/src/file/app/RunFile.php b/php/src/file/app/RunFile.php
index 501930d..52679be 100644
--- a/php/src/file/app/RunFile.php
+++ b/php/src/file/app/RunFile.php
@@ -39,6 +39,8 @@ class RunFile {
     $dateStart = $withDateStart? new DateTime(): null;
     return [
       "name" => $this->name,
+      "id" => bin2hex(random_bytes(16)),
+      "pid" => posix_getpid(),
       "serial" => 0,
       "date_start" => $dateStart,
       "date_stop" => null,
diff --git a/php/src/text/Word.php b/php/src/text/Word.php
index b514872..4c73019 100644
--- a/php/src/text/Word.php
+++ b/php/src/text/Word.php
@@ -44,7 +44,7 @@ class Word {
       $spec = substr($spec, strlen($ms[0]));
     } elseif (preg_match('/^m(asc(ulin)?)?\s*:\s*/i', $spec, $ms)) {
       $fem = false;
-      $spec = substr($spec, $ms[0]);
+      $spec = substr($spec, strlen($ms[0]));
     } elseif (preg_match('/\s*\|f(?:[eé]m(?:inin)?)?\s*$/iu', $spec, $ms, PREG_OFFSET_CAPTURE)) {
       $fem = true;
       $spec = substr($spec, 0, $ms[0][1]);
diff --git a/php/tests/db/sqlite/SqliteCapacitorTest.php b/php/tests/db/sqlite/SqliteStorageTest.php
similarity index 61%
rename from php/tests/db/sqlite/SqliteCapacitorTest.php
rename to php/tests/db/sqlite/SqliteStorageTest.php
index 1d324c7..65ac92f 100644
--- a/php/tests/db/sqlite/SqliteCapacitorTest.php
+++ b/php/tests/db/sqlite/SqliteStorageTest.php
@@ -5,32 +5,32 @@ use nulib\tests\TestCase;
 use nulib\db\Capacitor;
 use nulib\db\CapacitorChannel;
 
-class SqliteCapacitorTest extends TestCase {
-  function _testChargeStrings(SqliteCapacitor $capacitor, ?string $channel) {
-    $capacitor->reset($channel);
-    $capacitor->charge($channel, "first");
-    $capacitor->charge($channel, "second");
-    $capacitor->charge($channel, "third");
-    $items = iterator_to_array($capacitor->discharge($channel, null, false));
+class SqliteStorageTest extends TestCase {
+  function _testChargeStrings(SqliteStorage $storage, ?string $channel) {
+    $storage->reset($channel);
+    $storage->charge($channel, "first");
+    $storage->charge($channel, "second");
+    $storage->charge($channel, "third");
+    $items = iterator_to_array($storage->discharge($channel, false));
     self::assertSame(["first", "second", "third"], $items);
   }
 
-  function _testChargeArrays(SqliteCapacitor $capacitor, ?string $channel) {
-    $capacitor->reset($channel);
-    $capacitor->charge($channel, ["id" => 10, "name" => "first"]);
-    $capacitor->charge($channel, ["name" => "second", "id" => 20]);
-    $capacitor->charge($channel, ["name" => "third", "id" => "30"]);
+  function _testChargeArrays(SqliteStorage $storage, ?string $channel) {
+    $storage->reset($channel);
+    $storage->charge($channel, ["id" => 10, "name" => "first"]);
+    $storage->charge($channel, ["name" => "second", "id" => 20]);
+    $storage->charge($channel, ["name" => "third", "id" => "30"]);
   }
 
   function testChargeStrings() {
-    $capacitor = new SqliteCapacitor(__DIR__.'/capacitor.db');
-    $this->_testChargeStrings($capacitor, null);
-    $capacitor->close();
+    $storage = new SqliteStorage(__DIR__.'/capacitor.db');
+    $this->_testChargeStrings($storage, null);
+    $storage->close();
   }
 
   function testChargeArrays() {
-    $capacitor = new SqliteCapacitor(__DIR__.'/capacitor.db');
-    $capacitor->addChannel(new class extends CapacitorChannel {
+    $storage = new SqliteStorage(__DIR__.'/capacitor.db');
+    $storage->addChannel(new class extends CapacitorChannel {
       const NAME = "arrays";
       function getKeyDefinitions(): ?array {
         return ["id" => "integer"];
@@ -40,14 +40,14 @@ class SqliteCapacitorTest extends TestCase {
       }
     });
 
-    $this->_testChargeStrings($capacitor, "strings");
-    $this->_testChargeArrays($capacitor, "arrays");
-    $capacitor->close();
+    $this->_testChargeStrings($storage, "strings");
+    $this->_testChargeArrays($storage, "arrays");
+    $storage->close();
   }
 
   function testEach() {
-    $capacitor = new SqliteCapacitor(__DIR__.'/capacitor.db');
-    $capacitor = new Capacitor($capacitor, new class extends CapacitorChannel {
+    $storage = new SqliteStorage(__DIR__.'/capacitor.db');
+    $capacitor = new Capacitor($storage, new class extends CapacitorChannel {
       const NAME = "each";
 
       function getKeyDefinitions(): ?array {
@@ -73,7 +73,7 @@ class SqliteCapacitorTest extends TestCase {
       $updates = ["done" => 1];
       if ($suffix !== null) {
         $item["name"] .= $suffix;
-        $updates["_item"] = $item;
+        $updates["item"] = $item;
       }
       return $updates;
     };
@@ -86,19 +86,19 @@ class SqliteCapacitorTest extends TestCase {
   }
 
   function testPrimayKey() {
-    $capacitor = new SqliteCapacitor(__DIR__.'/capacitor.db');
-    $capacitor = new Capacitor($capacitor, new class extends CapacitorChannel {
+    $storage = new SqliteStorage(__DIR__.'/capacitor.db');
+    $capacitor = new Capacitor($storage, new class extends CapacitorChannel {
       const NAME = "pk";
 
       function getKeyDefinitions(): ?array {
         return [
-          "_id" => "varchar primary key",
+          "id_" => "varchar primary key",
           "done" => "integer default 0",
         ];
       }
       function getKeyValues($item): ?array {
         return [
-          "_id" => $item["numero"],
+          "id_" => $item["numero"],
         ];
       }
     });
diff --git a/php/tests/db/sqlite/_queryTest.php b/php/tests/db/sqlite/_queryTest.php
index 30290de..92c232d 100644
--- a/php/tests/db/sqlite/_queryTest.php
+++ b/php/tests/db/sqlite/_queryTest.php
@@ -15,6 +15,11 @@ class _queryTest extends TestCase {
     self::assertNull($sql);
     self::assertNull($params);
 
+    $sql = $params = null;
+    _query::parse_conds(["col" => null], $sql, $params);
+    self::assertSame(["col is null"], $sql);
+    self::assertNull($params);
+
     $sql = $params = null;
     _query::parse_conds(["col = 'value'"], $sql, $params);
     self::assertSame(["col = 'value'"], $sql);