add dropColumn schema migration feature

src/DB2Connection.php

@@ -2,15 +2,16 @@
 
 namespace Cooperl\Database\DB2;
 
-use Cooperl\Database\DB2\Query\Processors\DB2ZOSProcessor;
 use PDO;
 
 use Illuminate\Database\Connection;
 
 use Cooperl\Database\DB2\Schema\Builder;
 use Cooperl\Database\DB2\Query\Processors\DB2Processor;
+use Cooperl\Database\DB2\Query\Processors\DB2ZOSProcessor;
 use Cooperl\Database\DB2\Query\Grammars\DB2Grammar as QueryGrammar;
 use Cooperl\Database\DB2\Schema\Grammars\DB2Grammar as SchemaGrammar;
+use Cooperl\Database\DB2\Schema\Grammars\DB2ExpressCGrammar;
 
 /**
  * Class DB2Connection
@@ -67,14 +68,25 @@ public function resetCurrentSchema()
      */
     public function setCurrentSchema($schema)
     {
-        //$this->currentSchema = $schema;
         $this->statement('SET SCHEMA ?', [strtoupper($schema)]);
     }
 
+    /**
+     * Execute a system command on IBMi.
+     *
+     * @param $command
+     *
+     * @return string
+     */
+    public function executeCommand($command)
+    {
+        $this->statement('CALL QSYS2.QCMDEXC(?)', [$command]);
+    }
+
     /**
      * Get a schema builder instance for the connection.
      *
-     * @return \Illuminate\Database\Schema\MySqlBuilder
+     * @return \Cooperl\Database\DB2\Schema\Builder
      */
     public function getSchemaBuilder()
     {
@@ -121,7 +133,7 @@ protected function getDefaultSchemaGrammar()
     /**
      * Get the default post processor instance.
      *
-     * @return \Illuminate\Database\Query\Processors\PostgresProcessor
+     * @return \Cooperl\Database\DB2\Query\Processors\DB2Processor|\Cooperl\Database\DB2\Query\Processors\DB2ZOSProcessor
      */
     protected function getDefaultPostProcessor()
     {

src/Query/Grammars/DB2Grammar.php

@@ -104,7 +104,7 @@ protected function compileAnsiOffset(Builder $query, $components)
         }
 
         $components['columns'] = $this->compileOver($orderings, $columns);
-        
+
         // if there are bindings in the order, we need to move them to the select since we are moving the parameter
         // markers there with the OVER statement
         if(isset($query->getRawBindings()['order'])){
@@ -198,7 +198,7 @@ public function compileExists(Builder $query)
 
         $existsQuery->columns = [];
 
-        return $this->compileSelect($existsQuery->selectRaw('1')->limit(1));
+        return $this->compileSelect($existsQuery->selectRaw('1 exists')->limit(1));
     }
 
     /**

src/Schema/Blueprint.php

@@ -2,6 +2,9 @@
 
 namespace Cooperl\Database\DB2\Schema;
 
+use Illuminate\Database\Connection;
+use Illuminate\Database\Schema\Grammars\Grammar;
+
 /**
  * Class Blueprint
  *
@@ -10,27 +13,62 @@
 class Blueprint extends \Illuminate\Database\Schema\Blueprint
 {
 
-    public function synchro($index, $masterizable = false)
+   /**
+     * The sequence number of reply list entries.
+     *
+     * @var int
+     */
+    private $replyListSequenceNumber;
+
+    /**
+     * Get the sequence number of reply list entries.
+     *
+     * @return int
+     */
+    public function getReplyListSequenceNumber()
     {
+        return $this->replyListSequenceNumber;
+    }
 
-        $this->string('id_sync', 20)
-             ->index($index);
-        $this->string('hashcode', 32);
+    /**
+     * Set the sequence number of reply list entries.
+     *
+     * @param int $replyListSequenceNumber
+     * @return void
+     */
+    public function setReplyListSequenceNumber(int $replyListSequenceNumber)
+    {
+        return $this->replyListSequenceNumber = $replyListSequenceNumber;
+    }
 
-        if (true === $masterizable) {
-            $this->boolean('data_master')
-                 ->default(true);
-        }
+    /**
+     * Get the raw SQL statements for the blueprint.
+     *
+     * @param  \Illuminate\Database\Connection  $connection
+     * @param  \Illuminate\Database\Schema\Grammars\Grammar  $grammar
+     * @return array
+     */
+    public function toSql(Connection $connection, Grammar $grammar)
+    {
+        $this->addReplyListEntryCommands($connection);
+
+        return parent::toSql($connection, $grammar);
     }
 
     /**
-     * @param string $index
+     * Add the commands that are necessary to DROP and Rename statements on IBMi.
+     *
+     * @param  \Illuminate\Database\Connection  $connection
+     * @return void
      */
-    public function dropSynchro($index)
+    protected function addReplyListEntryCommands(Connection $connection)
     {
-        $this->dropColumn('id_sync', 'hashcode');
-        $this->dropIndex($index);
+        if ($this->commandsNamed(['dropColumn', 'renameColumn'])->count() > 0) {
+            array_unshift($this->commands, $this->createCommand('addReplyListEntry'), $this->createCommand('changeJob'));
+            array_push($this->commands, $this->createCommand('removeReplyListEntry'));
+        }
     }
+
     /**
      * Specify a system name for the table.
      *
@@ -124,4 +162,26 @@ public function numeric($column, $total = 8, $places = 2)
     {
         return $this->addColumn('numeric', $column, compact('total', 'places'));
     }
+
+    public function synchro($index, $masterizable = false)
+    {
+
+        $this->string('id_sync', 20)
+             ->index($index);
+        $this->string('hashcode', 32);
+
+        if (true === $masterizable) {
+            $this->boolean('data_master')
+                 ->default(true);
+        }
+    }
+
+    /**
+     * @param string $index
+     */
+    public function dropSynchro($index)
+    {
+        $this->dropColumn('id_sync', 'hashcode');
+        $this->dropIndex($index);
+    }
 }

src/Schema/Grammars/DB2Grammar.php

@@ -831,4 +831,83 @@ protected function getDefaultValue($value)
 
         return "'" . strval($value) . "'";
     }
+
+    /**
+     * Compile a executeCommand command.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint $blueprint
+     * @param  \Illuminate\Support\Fluent            $command
+     *
+     * @return string
+     */
+    private function compileExecuteCommand(Blueprint $blueprint, Fluent $command)
+    {
+        return "CALL QSYS2.QCMDEXC('" . $command->command . "')";
+    }
+
+    /**
+     * Compile an addReplyListEntry command.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint $blueprint
+     * @param  \Illuminate\Support\Fluent            $command
+     * @param  \Illuminate\Database\Connection  $connection
+     *
+     * @return string
+     */
+    public function compileAddReplyListEntry(Blueprint $blueprint, Fluent $command, Connection $connection)
+    {
+        $sequenceNumberQuery = <<<EOT
+            with reply_list_info(sequence_number) as (
+                values(1)
+                union all
+                select sequence_number + 1
+                from reply_list_info
+                where sequence_number + 1 between 2 and 9999
+            )
+            select min(sequence_number) sequence_number
+            from reply_list_info
+            where not exists (
+                select 1
+                from qsys2.reply_list_info rli
+                where rli.sequence_number = reply_list_info.sequence_number
+            )
+EOT;
+
+        $blueprint->setReplyListSequenceNumber($sequenceNumber = $connection->selectOne($sequenceNumberQuery)->sequence_number);
+        $command->command = "ADDRPYLE SEQNBR($sequenceNumber) MSGID(CPA32B2) RPY(''I'')";
+
+        return $this->compileExecuteCommand($blueprint, $command);
+    }
+
+    /**
+     * Compile a removeReplyListEntry command.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint $blueprint
+     * @param  \Illuminate\Support\Fluent            $command
+     *
+     * @return string
+     */
+    public function compileRemoveReplyListEntry(Blueprint $blueprint, Fluent $command)
+    {
+        $sequenceNumber = $blueprint->getReplyListSequenceNumber();
+        $command->command = "RMVRPYLE SEQNBR($sequenceNumber)";
+
+        return $this->compileExecuteCommand($blueprint, $command);
+    }
+
+    /**
+     * Compile a changeJob command.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint $blueprint
+     * @param  \Illuminate\Support\Fluent            $command
+     *
+     * @return string
+     */
+    public function compileChangeJob(Blueprint $blueprint, Fluent $command)
+    {
+        $command->command = 'CHGJOB INQMSGRPY(*SYSRPYL)';
+
+        return $this->compileExecuteCommand($blueprint, $command);
+    }
+
 }