Fix AlterTable::dropConstraint() by allowing the use of decorator

docs/book/sql-ddl.md

@@ -102,8 +102,32 @@ $table->changeColumn('name', Column\Varchar('new_name', 50));
 You may also *drop* existing columns or constraints:
 
 ```php
+use \Zend\Db\Metadata\Object\ConstraintObject;
+
 $table->dropColumn('foo');
-$table->dropConstraint('my_index');
+
+$constraint = new ConstraintObject('my_index', null);
+$table->dropConstraint($constraint);
+```
+
+Notice: On MySQL, you need to specify the type of constraint you want to drop.
+To do so you may use a `\Zend\Db\Metadata\Object\ConstraintObject` and set its
+type accordingly or directly a subclass of
+`\Zend\Db\Sql\Ddl\Constraint\ConstraintInterface`.
+```php
+use \Zend\Db\Metadata\Object\ConstraintObject;
+
+$fkConstraint = new ConstraintObject('my_fk', null);
+$fkConstraint->setType('FOREIGN KEY');
+$table->dropConstraint($fkConstraint);
+```
+
+```php
+use \Zend\Db\Sql\Ddl\Constraint\UniqueKey;
+$idxConstraint = new \Zend\Db\Sql\Ddl\Constraint\UniqueKey(
+    null, 'my_unique_index'
+);
+$table->dropConstraint($idxConstraint);
 ```
 
 ## Dropping Tables

src/Sql/Ddl/AlterTable.php

@@ -10,6 +10,7 @@
 namespace Zend\Db\Sql\Ddl;
 
 use Zend\Db\Adapter\Platform\PlatformInterface;
+use Zend\Db\Metadata\Object\ConstraintObject;
 use Zend\Db\Sql\AbstractSql;
 use Zend\Db\Sql\TableIdentifier;
 
@@ -28,7 +29,7 @@ class AlterTable extends AbstractSql implements SqlInterface
     protected $addColumns = [];
 
     /**
-     * @var array
+     * @var Constraint\ConstraintInterface[]
      */
     protected $addConstraints = [];
 
@@ -43,7 +44,7 @@ class AlterTable extends AbstractSql implements SqlInterface
     protected $dropColumns = [];
 
     /**
-     * @var array
+     * @var Constraint\ConstraintInterface[]|ConstraintObject[]
      */
     protected $dropConstraints = [];
 
@@ -75,7 +76,7 @@ class AlterTable extends AbstractSql implements SqlInterface
         ],
         self::DROP_CONSTRAINTS  => [
             "%1\$s" => [
-                [1 => "DROP CONSTRAINT %1\$s,\n", 'combinedby' => ""],
+                [1 => "DROP CONSTRAINT %1\$s,\n", 'combinedby' => " "],
             ]
         ]
     ];
@@ -139,12 +140,12 @@ public function dropColumn($name)
     }
 
     /**
-     * @param  string $name
+     * @param  Constraint\ConstraintInterface|ConstraintObject $constraint
      * @return self Provides a fluent interface
      */
-    public function dropConstraint($name)
+    public function dropConstraint($constraint)
     {
-        $this->dropConstraints[] = $name;
+        $this->dropConstraints[] = $constraint;
 
         return $this;
     }
@@ -230,7 +231,7 @@ protected function processDropConstraints(PlatformInterface $adapterPlatform = n
     {
         $sqls = [];
         foreach ($this->dropConstraints as $constraint) {
-            $sqls[] = $adapterPlatform->quoteIdentifier($constraint);
+            $sqls[] = $adapterPlatform->quoteIdentifier($constraint->getName());
         }
 
         return [$sqls];

src/Sql/Ddl/Constraint/ConstraintInterface.php

@@ -14,4 +14,6 @@
 interface ConstraintInterface extends ExpressionInterface
 {
     public function getColumns();
+
+    public function getName();
 }

src/Sql/Platform/Mysql/Ddl/AlterTableDecorator.php

@@ -10,7 +10,11 @@
 namespace Zend\Db\Sql\Platform\Mysql\Ddl;
 
 use Zend\Db\Adapter\Platform\PlatformInterface;
+use Zend\Db\Metadata\Object\ConstraintObject;
 use Zend\Db\Sql\Ddl\AlterTable;
+use Zend\Db\Sql\Ddl\Constraint\ForeignKey;
+use Zend\Db\Sql\Ddl\Constraint\PrimaryKey;
+use Zend\Db\Sql\Ddl\Index\AbstractIndex;
 use Zend\Db\Sql\Platform\PlatformDecoratorInterface;
 
 class AlterTableDecorator extends AlterTable implements PlatformDecoratorInterface
@@ -43,6 +47,11 @@ class AlterTableDecorator extends AlterTable implements PlatformDecoratorInterfa
     public function setSubject($subject)
     {
         $this->subject = $subject;
+        $this->subject->specifications[self::DROP_CONSTRAINTS] = [
+            "%1\$s" => [
+                [2 => "DROP %1\$s %2\$s,\n", 'combinedby' => " "],
+            ]
+        ];
 
         return $this;
     }
@@ -248,4 +257,37 @@ private function compareColumnOptions($columnA, $columnB)
 
         return $columnA - $columnB;
     }
+
+    protected function processDropConstraints(PlatformInterface $adapterPlatform = null)
+    {
+        $sqls = [];
+        foreach ($this->dropConstraints as $constraint) {
+            $sqls[] = [
+                $this->getConstraintType($constraint),
+                $adapterPlatform->quoteIdentifier($constraint->getName())
+            ];
+        }
+
+        return [$sqls];
+    }
+
+    /**
+     * @param $constraint
+     * @return string
+     */
+    protected function getConstraintType($constraint)
+    {
+        if ($constraint instanceof ConstraintObject) {
+            return $constraint->getType();
+        }
+        if ($constraint instanceof PrimaryKey) {
+            return 'PRIMARY KEY';
+        } elseif ($constraint instanceof ForeignKey) {
+            return 'FOREIGN KEY';
+        } elseif ($constraint instanceof AbstractIndex) {
+            return 'INDEX';
+        } else {
+            return 'KEY';
+        }
+    }
 }

test/unit/Sql/Ddl/AlterTableTest.php

@@ -10,6 +10,7 @@
 namespace ZendTest\Db\Sql\Ddl;
 
 use PHPUnit\Framework\TestCase;
+use Zend\Db\Metadata\Object\ConstraintObject;
 use Zend\Db\Sql\Ddl\AlterTable;
 use Zend\Db\Sql\Ddl\Column;
 use Zend\Db\Sql\Ddl\Constraint;
@@ -68,8 +69,9 @@ public function testDropColumn()
     public function testDropConstraint()
     {
         $at = new AlterTable();
-        self::assertSame($at, $at->dropConstraint('foo'));
-        self::assertEquals(['foo'], $at->getRawState($at::DROP_CONSTRAINTS));
+        $constraint = new ConstraintObject('foo', null);
+        $this->assertSame($at, $at->dropConstraint($constraint));
+        $this->assertEquals([$constraint], $at->getRawState($at::DROP_CONSTRAINTS));
     }
 
     /**
@@ -95,14 +97,16 @@ public function testGetSqlString()
         $at->changeColumn('name', new Column\Varchar('new_name', 50));
         $at->dropColumn('foo');
         $at->addConstraint(new Constraint\ForeignKey('my_fk', 'other_id', 'other_table', 'id', 'CASCADE', 'CASCADE'));
-        $at->dropConstraint('my_index');
+        $at->dropConstraint(new ConstraintObject('my_index', null));
+        $at->dropConstraint(new Constraint\UniqueKey(null, 'my_unique_index'));
         $expected = <<<EOS
 ALTER TABLE "foo"
  ADD COLUMN "another" VARCHAR(255) NOT NULL,
  CHANGE COLUMN "name" "new_name" VARCHAR(50) NOT NULL,
  DROP COLUMN "foo",
  ADD CONSTRAINT "my_fk" FOREIGN KEY ("other_id") REFERENCES "other_table" ("id") ON DELETE CASCADE ON UPDATE CASCADE,
- DROP CONSTRAINT "my_index"
+ DROP CONSTRAINT "my_index",
+ DROP CONSTRAINT "my_unique_index"
 EOS;
 
         $actual = $at->getSqlString();

test/unit/Sql/Platform/Mysql/Ddl/AlterTableDecoratorTest.php

@@ -11,9 +11,11 @@
 
 use PHPUnit\Framework\TestCase;
 use Zend\Db\Adapter\Platform\Mysql;
+use Zend\Db\Metadata\Object\ConstraintObject;
 use Zend\Db\Sql\Ddl\AlterTable;
 use Zend\Db\Sql\Ddl\Column\Column;
 use Zend\Db\Sql\Ddl\Constraint\PrimaryKey;
+use Zend\Db\Sql\Ddl\Constraint\UniqueKey;
 use Zend\Db\Sql\Platform\Mysql\Ddl\AlterTableDecorator;
 
 class AlterTableDecoratorTest extends TestCase
@@ -46,9 +48,17 @@ public function testGetSqlString()
         $col->addConstraint(new PrimaryKey());
         $ct->addColumn($col);
 
-        self::assertEquals(
+        $fk = new ConstraintObject('my_fk', null);
+        $fk->setType('FOREIGN KEY');
+        $ct->dropConstraint($fk);
+
+        $ct->dropConstraint(new UniqueKey(null, 'my_unique_index'));
+
+        $this->assertEquals(
             "ALTER TABLE `foo`\n ADD COLUMN `bar` INTEGER UNSIGNED ZEROFILL " .
-            "NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'baz' AFTER `bar`",
+            "NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'baz' AFTER `bar`,\n" .
+            "    DROP FOREIGN KEY `my_fk`,\n" .
+            " DROP KEY `my_unique_index`",
             @$ctd->getSqlString(new Mysql())
         );
     }