diff --git a/php/src/db/Capacitor.php b/php/src/db/Capacitor.php
index aa5da52..5528a68 100644
--- a/php/src/db/Capacitor.php
+++ b/php/src/db/Capacitor.php
@@ -39,6 +39,12 @@ class Capacitor implements ITransactor {
     return $this->getChannel()->getTableName();
   }
 
+  function getCreateSql(): string {
+    $storage = $this->storage;
+    $channel = $this->channel;
+    return $storage->_getMigration($channel)->getSql(get_class($channel), $this->db());
+  }
+
   /** @var CapacitorChannel[]  */
   protected ?array $subChannels = null;
 
diff --git a/php/src/db/CapacitorChannel.php b/php/src/db/CapacitorChannel.php
index b0649ae..c7265bb 100644
--- a/php/src/db/CapacitorChannel.php
+++ b/php/src/db/CapacitorChannel.php
@@ -66,26 +66,47 @@ class CapacitorChannel implements ITransactor {
     $columnDefinitions = cl::withn(static::COLUMN_DEFINITIONS);
     $primaryKeys = cl::withn(static::PRIMARY_KEYS);
     $migration = cl::withn(static::MIGRATION);
+    $lastMkey = 1;
     if ($columnDefinitions !== null) {
       # mettre à jour la liste des clés primaires et des migrations
       $index = 0;
       foreach ($columnDefinitions as $col => $def) {
         if ($col === $index) {
-          # si définition séquentielle, seules les définitions de clé
-          # primaires sont supportées
           $index++;
-          if (preg_match('/\bprimary\s+key\s+\((.+)\)/i', $def, $ms)) {
-            $primaryKeys = preg_split('/\s*,\s*/', trim($ms[1]));
-          }
-        } elseif (is_array($def)) {
-          # tableau: c'est une migration
-          $def = implode(" ", $def);
-          if ($def) {
-            $migration["add_$col"] = "alter table $tableName add column $col $def";
+          if (is_array($def)) {
+            # tableau: c'est une migration
+            $mkey = null;
+            $mvalues = null;
+            $mdefs = $def;
+            $mindex = 0;
+            foreach ($mdefs as $mcol => $mdef) {
+              if ($mindex === 0 && $mcol === 0) {
+                $mindex++;
+                $mkey = $mdef;
+              } elseif ($mcol === $mindex) {
+                # si définition séquentielle, prendre la migration telle quelle
+                $mindex++;
+                $mvalues[] = $mdef;
+              } elseif ($mdef) {
+                # mise à jour d'une colonne
+                $mvalues[] = "alter table $tableName add column $mcol $mdef";
+              } else {
+                # suppression d'une colonne
+                $mvalues[] = "alter table $tableName drop column $mcol";
+              }
+            }
+            if ($mvalues !== null) {
+              if ($mkey === null) $mkey = $lastMkey++;
+              $migration[$mkey] = $mvalues;
+            }
           } else {
-            $migration["drop_$col"] = "alter table $tableName drop column $col";
+            # si définition séquentielle, seules les définitions de clé
+            # primaires sont supportées
+            if (preg_match('/\bprimary\s+key\s+\((.+)\)/i', $def, $ms)) {
+              $primaryKeys = preg_split('/\s*,\s*/', trim($ms[1]));
+            }
           }
-        } elseif (is_scalar($def)) {
+        } else {
           # chaine: c'est une définition
           $def = strval($def);
           if (preg_match('/\bprimary\s+key\b/i', $def)) {
diff --git a/php/src/db/CapacitorStorage.php b/php/src/db/CapacitorStorage.php
index 1773198..e7ff6af 100644
--- a/php/src/db/CapacitorStorage.php
+++ b/php/src/db/CapacitorStorage.php
@@ -40,6 +40,16 @@ abstract class CapacitorStorage {
   const SERSUM_DEFINITION = "varchar(40)";
   const SERTS_DEFINITION = "datetime";
 
+  protected static function sercol($def): string {
+    if (!is_string($def)) $def = strval($def);
+    switch ($def) {
+    case "serdata": $def = static::SERDATA_DEFINITION; break;
+    case "sersum": $def = static::SERSUM_DEFINITION; break;
+    case "serts": $def = static::SERTS_DEFINITION; break;
+    }
+    return $def;
+  }
+
   const COLUMN_DEFINITIONS = [
     "item__" => "serdata",
     "item__sum_" => "sersum",
@@ -61,22 +71,29 @@ abstract class CapacitorStorage {
     $constraints = [];
     $index = 0;
     foreach ($tmp as $col => $def) {
-      switch ($def) {
-      case "serdata": $def = static::SERDATA_DEFINITION; break;
-      case "sersum": $def = static::SERSUM_DEFINITION; break;
-      case "serts": $def = static::SERTS_DEFINITION; break;
-      }
       if ($col === $index) {
         $index++;
-        $constraints[] = $def;
-      } elseif (is_array($def)) {
-        # éventuellement, ignorer les migrations
-        $def = implode(" ", $def);
-        if ($def && !$ignoreMigrations) {
-          $definitions[$col] = $def;
+        if (is_array($def)) {
+          if (!$ignoreMigrations) {
+            $mdefs = $def;
+            $mindex = 0;
+            foreach ($mdefs as $mcol => $mdef) {
+              if ($mcol === $mindex) {
+                $mindex++;
+              } else {
+                if ($mdef) {
+                  $definitions[$mcol] = self::sercol($mdef);
+                } else {
+                  unset($definitions[$mcol]);
+                }
+              }
+            }
+          }
+        } else {
+          $constraints[] = $def;
         }
-      } elseif (is_scalar($def)) {
-        $definitions[$col] = strval($def);
+      } else {
+        $definitions[$col] = self::sercol($def);
       }
     }
     return cl::merge($definitions, $constraints);
@@ -155,17 +172,6 @@ abstract class CapacitorStorage {
     ];
   }
 
-  protected static function format_sql(CapacitorChannel $channel, string $sql): string {
-    $class = get_class($channel);
-    return <<<EOT
--- -*- coding: utf-8 mode: sql -*- vim:sw=4:sts=4:et:ai:si:sta:fenc=utf-8
--- autogénéré à partir de $class
-
-$sql;
-
-EOT;
-  }
-
   abstract protected function tableExists(string $tableName): bool;
 
   const METADATA_TABLE = "_metadata";
@@ -183,7 +189,7 @@ EOT;
       ]);
       $db->exec([
         "drop table if exists",
-        "table" => _migration::MIGRATION_TABLE
+        "table" => _migration::MIGRATION_TABLE,
       ]);
       $db->exec([
         "create table",
diff --git a/php/src/db/IDatabase.php b/php/src/db/IDatabase.php
index dc71720..1383c9a 100644
--- a/php/src/db/IDatabase.php
+++ b/php/src/db/IDatabase.php
@@ -2,6 +2,9 @@
 namespace nulib\db;
 
 interface IDatabase extends ITransactor {
+  /** obtenir la requête SQL correspondant à $query */
+  function getSql($query, ?array $params=null): string;
+
   /**
    * - si c'est un insert, retourner l'identifiant autogénéré de la ligne
    * - sinon retourner le nombre de lignes modifiées en cas de succès, ou false
diff --git a/php/src/db/_private/_base.php b/php/src/db/_private/_base.php
index 5e366e6..2ca42f9 100644
--- a/php/src/db/_private/_base.php
+++ b/php/src/db/_private/_base.php
@@ -1,8 +1,6 @@
 <?php
 namespace nulib\db\_private;
 
-use nulib\cl;
-use nulib\str;
 use nulib\ValueException;
 
 abstract class _base extends _common {
diff --git a/php/src/db/_private/_generic.php b/php/src/db/_private/_generic.php
index dea829c..d71e157 100644
--- a/php/src/db/_private/_generic.php
+++ b/php/src/db/_private/_generic.php
@@ -1,9 +1,7 @@
 <?php
 namespace nulib\db\_private;
 
-use nulib\cl;
 use nulib\str;
-use nulib\ValueException;
 
 class _generic extends _common {
   const SCHEMA = [
diff --git a/php/src/db/_private/_migration.php b/php/src/db/_private/_migration.php
index f11cbb8..79d8686 100644
--- a/php/src/db/_private/_migration.php
+++ b/php/src/db/_private/_migration.php
@@ -1,6 +1,7 @@
 <?php
 namespace nulib\db\_private;
 
+use nulib\cl;
 use nulib\db\IDatabase;
 use nulib\php\func;
 
@@ -61,12 +62,38 @@ abstract class _migration {
     foreach ($this->migrations as $name => $migration) {
       if ($this->isMigrated($name)) continue;
       $this->setMigrated($name, false);
-      if (is_string($migration) || !func::is_callable($migration)) {
-        $db->exec($migration);
-      } else {
+      if (func::is_callable($migration)) {
         func::with($migration)->bind($this)->invoke([$db, $name]);
+      } else {
+        foreach (cl::with($migration) as $query) {
+          $db->exec($query);
+        }
       }
       $this->setMigrated($name, true);
     }
   }
+
+  protected static function sql_prefix(?string $source=null): string {
+    $prefix = "-- -*- coding: utf-8 mode: sql -*- vim:sw=4:sts=4:et:ai:si:sta:fenc=utf-8\n";
+    if ($source !== null) $prefix .= "-- autogénéré à partir de $source\n";
+    return $prefix;
+  }
+
+  function getSql(?string $source=null, ?IDatabase $db=null): string {
+    $db = ($this->db ??= $db);
+    $lines = [self::sql_prefix($source)];
+    foreach ($this->migrations as $name => $migration) {
+      $lines[] = "-- $name";
+      if (func::is_callable($migration)) {
+        $lines[] = "-- <fonction PHP>";
+      } else {
+        foreach (cl::with($migration) as $query) {
+          $sql = $db->getSql($query);
+          $lines[] = "$sql;";
+        }
+      }
+      $lines[] = "";
+    }
+    return implode("\n", $lines);
+  }
 }
diff --git a/php/src/db/mysql/MysqlStorage.php b/php/src/db/mysql/MysqlStorage.php
index 4f27f1a..ace8beb 100644
--- a/php/src/db/mysql/MysqlStorage.php
+++ b/php/src/db/mysql/MysqlStorage.php
@@ -41,14 +41,10 @@ class MysqlStorage extends CapacitorStorage {
   ];
 
   function _getMigration(CapacitorChannel $channel): _mysqlMigration {
-    return new _mysqlMigration(cl::merge([
-      $this->_createSql($channel),
-    ], $channel->getMigration()), $channel->getName());
-  }
-
-  function _getCreateSql(CapacitorChannel $channel): string {
-    $query = new _mysqlQuery($this->_createSql($channel));
-    return self::format_sql($channel, $query->getSql());
+    $migrations = cl::merge([
+      "0init" => [$this->_createSql($channel)],
+    ], $channel->getMigration());
+    return new _mysqlMigration($migrations, $channel->getName());
   }
 
   const CHANNELS_COLS = [
diff --git a/php/src/db/pdo/Pdo.php b/php/src/db/pdo/Pdo.php
index 78e38db..f34ff69 100644
--- a/php/src/db/pdo/Pdo.php
+++ b/php/src/db/pdo/Pdo.php
@@ -1,7 +1,6 @@
 <?php
 namespace nulib\db\pdo;
 
-use Generator;
 use nulib\cl;
 use nulib\db\_private\_config;
 use nulib\db\_private\Tvalues;
@@ -115,6 +114,11 @@ class Pdo implements IDatabase {
 
   protected ?\PDO $db = null;
 
+  function getSql($query, ?array $params=null): string {
+    $query = new _pdoQuery($query, $params);
+    return $query->getSql();
+  }
+
   function open(): self {
     if ($this->db === null) {
       $dbconn = $this->dbconn;
diff --git a/php/src/db/pgsql/Pgsql.php b/php/src/db/pgsql/Pgsql.php
index 34d82dc..dbcbedf 100644
--- a/php/src/db/pgsql/Pgsql.php
+++ b/php/src/db/pgsql/Pgsql.php
@@ -117,6 +117,11 @@ class Pgsql implements IDatabase {
   /** @var resource */
   protected $db = null;
 
+  function getSql($query, ?array $params=null): string {
+    $query = new _pgsqlQuery($query, $params);
+    return $query->getSql();
+  }
+
   function open(): self {
     if ($this->db === null) {
       $dbconn = $this->dbconn;
diff --git a/php/src/db/pgsql/PgsqlException.php b/php/src/db/pgsql/PgsqlException.php
index afd21c4..f9a500e 100644
--- a/php/src/db/pgsql/PgsqlException.php
+++ b/php/src/db/pgsql/PgsqlException.php
@@ -3,7 +3,6 @@ namespace nulib\db\pgsql;
 
 use Exception;
 use RuntimeException;
-use SQLite3;
 
 class PgsqlException extends RuntimeException {
   static final function last_error($db): self {
diff --git a/php/src/db/pgsql/PgsqlStorage.php b/php/src/db/pgsql/PgsqlStorage.php
index 0dc93b7..dd89e2a 100644
--- a/php/src/db/pgsql/PgsqlStorage.php
+++ b/php/src/db/pgsql/PgsqlStorage.php
@@ -42,14 +42,10 @@ class PgsqlStorage extends CapacitorStorage {
   }
 
   function _getMigration(CapacitorChannel $channel): _pgsqlMigration {
-    return new _pgsqlMigration(cl::merge([
-      $this->_createSql($channel),
-    ], $channel->getMigration()), $channel->getName());
-  }
-
-  function _getCreateSql(CapacitorChannel $channel): string {
-    $query = new _pgsqlQuery($this->_createSql($channel));
-    return self::format_sql($channel, $query->getSql());
+    $migrations = cl::merge([
+      "0init" => [$this->_createSql($channel)],
+    ], $channel->getMigration());
+    return new _pgsqlMigration($migrations, $channel->getName());
   }
 
   protected function _addToChannelsSql(CapacitorChannel $channel): array {
diff --git a/php/src/db/sqlite/Sqlite.php b/php/src/db/sqlite/Sqlite.php
index fffb8f1..ae4ea99 100644
--- a/php/src/db/sqlite/Sqlite.php
+++ b/php/src/db/sqlite/Sqlite.php
@@ -146,6 +146,11 @@ class Sqlite implements IDatabase {
 
   protected bool $inTransaction;
 
+  function getSql($query, ?array $params=null): string {
+    $query = new _sqliteQuery($query, $params);
+    return $query->getSql();
+  }
+
   function open(): self {
     if ($this->db === null) {
       $this->db = new SQLite3($this->file, $this->flags, $this->encryptionKey);
diff --git a/php/src/db/sqlite/SqliteStorage.php b/php/src/db/sqlite/SqliteStorage.php
index f031a56..4621cb2 100644
--- a/php/src/db/sqlite/SqliteStorage.php
+++ b/php/src/db/sqlite/SqliteStorage.php
@@ -34,14 +34,10 @@ class SqliteStorage extends CapacitorStorage {
   }
 
   function _getMigration(CapacitorChannel $channel): _sqliteMigration {
-    return new _sqliteMigration(cl::merge([
-      $this->_createSql($channel),
-    ], $channel->getMigration()), $channel->getName());
-  }
-
-  function _getCreateSql(CapacitorChannel $channel): string {
-    $query = new _sqliteQuery($this->_createSql($channel));
-    return self::format_sql($channel, $query->getSql());
+    $migrations = cl::merge([
+      "0init" => [$this->_createSql($channel)],
+    ], $channel->getMigration());
+    return new _sqliteMigration($migrations, $channel->getName());
   }
 
   function channelExists(string $name): bool {
diff --git a/php/src/db/sqlite/_sqliteQuery.php b/php/src/db/sqlite/_sqliteQuery.php
index 14fb1b0..04e6f1c 100644
--- a/php/src/db/sqlite/_sqliteQuery.php
+++ b/php/src/db/sqlite/_sqliteQuery.php
@@ -2,15 +2,8 @@
 namespace nulib\db\sqlite;
 
 use nulib\db\_private\_base;
-use nulib\db\_private\_create;
-use nulib\db\_private\_delete;
-use nulib\db\_private\_generic;
-use nulib\db\_private\_insert;
-use nulib\db\_private\_select;
-use nulib\db\_private\_update;
 use nulib\db\_private\Tbindings;
 use nulib\output\msg;
-use nulib\ValueException;
 use SQLite3;
 use SQLite3Stmt;
 
diff --git a/php/src/php/func.php b/php/src/php/func.php
index 90a1cff..675d359 100644
--- a/php/src/php/func.php
+++ b/php/src/php/func.php
@@ -3,7 +3,6 @@ namespace nulib\php;
 
 use Closure;
 use Exception;
-use Generator;
 use nulib\A;
 use nulib\cl;
 use nulib\cv;
@@ -268,6 +267,8 @@ class func {
           $reason = "$c::$f: method not found";
           return false;
         }
+        $method = new ReflectionMethod($c, $f);
+        if (!$method->isStatic()) return false;
       } else {
         $reason = "$c::$f: not bound";
       }
@@ -402,6 +403,8 @@ class func {
           $reason = "$c::$f: method not found";
           return false;
         }
+        $method = new ReflectionMethod($c, $f);
+        if ($method->isStatic()) return false;
       } else {
         $reason = "$c::$f: not bound";
       }
diff --git a/php/tests/db/sqlite/ChannelMigrationTest.php b/php/tests/db/sqlite/ChannelMigrationTest.php
new file mode 100644
index 0000000..1946179
--- /dev/null
+++ b/php/tests/db/sqlite/ChannelMigrationTest.php
@@ -0,0 +1,75 @@
+<?php
+namespace nulib\db\sqlite;
+
+use nulib\db\Capacitor;
+use nulib\db\sqlite\impl\MyChannel;
+use nulib\db\sqlite\impl\MyChannelV2;
+use nulib\db\sqlite\impl\MyChannelV3;
+use nulib\output\msg;
+use nulib\output\std\StdMessenger;
+use nulib\php\time\DateTime;
+use nulib\tests\TestCase;
+
+class ChannelMigrationTest extends TestCase {
+  static function setUpBeforeClass(): void {
+    parent::setUpBeforeClass();
+    msg::set_messenger_class(StdMessenger::class);
+  }
+
+  protected function addData(MyChannel $channel, array $data): void {
+    foreach ($data as [$name, $value, $dateCre, $dateMod, $age]) {
+      $channel->charge([
+        "name" => $name,
+        "value" => $value,
+        "date_cre" => $dateCre,
+        "date_mod" => $dateMod,
+        "age" => $age,
+      ]);
+    }
+  }
+
+  function testMigration() {
+    $storage = new SqliteStorage(__DIR__.'/capacitor.db');
+    $data = [
+      ["first", "premier", new DateTime(), new DateTime(), 15],
+      ["second", "deuxieme", new DateTime(), new DateTime(), 15],
+    ];
+
+    new Capacitor($storage, $channel = new MyChannel());
+    $channel->reset(true);
+    $this->addData($channel, $data);
+
+    new Capacitor($storage, $channel = new MyChannelV2());
+    $this->addData($channel, $data);
+
+    new Capacitor($storage, $channel = new MyChannelV3());
+    $this->addData($channel, $data);
+
+    $sql = $channel->getCapacitor()->getCreateSql();
+    $class = MyChannelV3::class;
+    $expected = <<<EOT
+-- -*- coding: utf-8 mode: sql -*- vim:sw=4:sts=4:et:ai:si:sta:fenc=utf-8
+-- autogénéré à partir de $class
+
+-- 0init
+create table  if not exists my (
+  id_ integer primary key autoincrement
+, name varchar
+, value varchar
+, item__ mediumtext
+, item__sum_ varchar(40)
+, created_ datetime
+, modified_ datetime
+);
+
+-- dates
+alter table my add column date_cre datetime;
+alter table my add column date_mod datetime;
+
+-- infos
+alter table my add column age integer;
+
+EOT;
+    self::assertSame($expected, $sql);
+  }
+}
diff --git a/php/tests/db/sqlite/impl/MyChannel.php b/php/tests/db/sqlite/impl/MyChannel.php
new file mode 100644
index 0000000..3cf5b69
--- /dev/null
+++ b/php/tests/db/sqlite/impl/MyChannel.php
@@ -0,0 +1,33 @@
+<?php
+namespace nulib\db\sqlite\impl;
+
+use nulib\db\CapacitorChannel;
+
+class MyChannel extends CapacitorChannel {
+  const NAME = "my";
+  const TABLE_NAME = "my";
+  const COLUMN_DEFINITIONS = [
+    "name" => "varchar not null primary key",
+    "value" => "varchar",
+  ];
+
+  const VERSION = 1;
+
+  function __construct() {
+    parent::__construct();
+    $this->version = static::VERSION;
+  }
+
+  protected int $version;
+
+  function getItemValues($item): ?array {
+
+    return [
+      "name" => "{$item["name"]}$this->version",
+      "value" => "{$item["value"]} v$this->version",
+      "date_cre" => $item["date_cre"] ?? null,
+      "date_mod" => $item["date_mod"] ?? null,
+      "age" => $item["age"] ?? null,
+    ];
+  }
+}
diff --git a/php/tests/db/sqlite/impl/MyChannelV2.php b/php/tests/db/sqlite/impl/MyChannelV2.php
new file mode 100644
index 0000000..68f18bf
--- /dev/null
+++ b/php/tests/db/sqlite/impl/MyChannelV2.php
@@ -0,0 +1,14 @@
+<?php
+namespace nulib\db\sqlite\impl;
+
+class MyChannelV2 extends MyChannel {
+  const VERSION = 2;
+  const COLUMN_DEFINITIONS = [
+    "name" => "varchar",
+    "value" => "varchar",
+    ["dates",
+      "date_cre" => "datetime",
+      "date_mod" => "datetime",
+    ],
+  ];
+}
diff --git a/php/tests/db/sqlite/impl/MyChannelV3.php b/php/tests/db/sqlite/impl/MyChannelV3.php
new file mode 100644
index 0000000..e6e2170
--- /dev/null
+++ b/php/tests/db/sqlite/impl/MyChannelV3.php
@@ -0,0 +1,17 @@
+<?php
+namespace nulib\db\sqlite\impl;
+
+class MyChannelV3 extends MyChannel {
+  const VERSION = 3;
+  const COLUMN_DEFINITIONS = [
+    "name" => "varchar",
+    "value" => "varchar",
+    ["dates",
+      "date_cre" => "datetime",
+      "date_mod" => "datetime",
+    ],
+    ["infos",
+      "age" => "integer",
+    ],
+  ];
+}
diff --git a/php/tests/php/funcTest.php b/php/tests/php/funcTest.php
index 22fa882..f15ce27 100644
--- a/php/tests/php/funcTest.php
+++ b/php/tests/php/funcTest.php
@@ -562,7 +562,7 @@ namespace nulib\php {
         true, true, [SC::class, "tstatic"],
       ],
       [[SC::class, "tmethod"],
-        true, true, [SC::class, "tmethod"],
+        false, true, [SC::class, "tmethod"],
         true, true, [SC::class, "tmethod"],
       ],
       [[SC::class, "->tmethod"],