Support for Partial Indexes for PostgreSql and Sqlite

Support for Partial Indexes was available in Doctrine 1 following
http://www.doctrine-project.org/jira/browse/DC-82. This commit
reintroduce support for Doctrine 2. We use the same syntax with an
optionnal "where" attribute for Index and UniqueConstraint.

lib/Doctrine/DBAL/Platforms/AbstractPlatform.php

@@ -1745,11 +1745,25 @@ abstract class AbstractPlatform
         }
 
         $query = 'CREATE ' . $this->getCreateIndexSQLFlags($index) . 'INDEX ' . $name . ' ON ' . $table;
-        $query .= ' (' . $this->getIndexFieldDeclarationListSQL($columns) . ')';
+        $query .= ' (' . $this->getIndexFieldDeclarationListSQL($columns) . ')' . $this->getPartialIndexSQL($index);
 
         return $query;
     }
 
+    /**
+     * Adds condition for partial index.
+     *
+     * @param \Doctrine\DBAL\Schema\Index $index
+     *
+     * @return string
+     */
+    protected function getPartialIndexSQL(Index $index)
+    {
+        $where = $index->getWhere();
+
+        return $this->supportsPartialIndexes() && $where ? ' WHERE ' . $where : '';
+    }
+
     /**
      * Adds additional flags for index generation.
      *
@@ -2302,7 +2316,7 @@ abstract class AbstractPlatform
 
         return 'CONSTRAINT ' . $name . ' UNIQUE ('
              . $this->getIndexFieldDeclarationListSQL($columns)
-             . ')';
+             . ')' . $this->getPartialIndexSQL($index);
     }
 
     /**
@@ -2326,7 +2340,7 @@ abstract class AbstractPlatform
 
         return $this->getCreateIndexSQLFlags($index) . 'INDEX ' . $name . ' ('
                 . $this->getIndexFieldDeclarationListSQL($columns)
-             . ')';
+                . ')' . $this->getPartialIndexSQL($index);
     }
 
     /**
@@ -3008,6 +3022,16 @@ abstract class AbstractPlatform
         return true;
     }
 
+    /**
+     * Whether the platform supports partial indexes.
+     *
+     * @return boolean
+     */
+    public function supportsPartialIndexes()
+    {
+        return false;
+    }
+
     /**
      * Whether the platform supports altering tables.
      *

lib/Doctrine/DBAL/Platforms/PostgreSqlPlatform.php

@@ -174,6 +174,16 @@ class PostgreSqlPlatform extends AbstractPlatform
         return true;
     }
 
+    /**
+     * Whether the platform supports partial indexes.
+     *
+     * @return boolean
+     */
+    public function supportsPartialIndexes()
+    {
+        return true;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -314,7 +324,8 @@ class PostgreSqlPlatform extends AbstractPlatform
     public function getListTableIndexesSQL($table, $currentDatabase = null)
     {
         return "SELECT quote_ident(relname) as relname, pg_index.indisunique, pg_index.indisprimary,
-                       pg_index.indkey, pg_index.indrelid
+                       pg_index.indkey, pg_index.indrelid,
+                       TRIM(BOTH '()' FROM pg_get_expr(indpred, indrelid)) AS where
                  FROM pg_class, pg_index
                  WHERE oid IN (
                     SELECT indexrelid

lib/Doctrine/DBAL/Platforms/SqlitePlatform.php

@@ -463,6 +463,16 @@ class SqlitePlatform extends AbstractPlatform
         return true;
     }
 
+    /**
+     * Whether the platform supports partial indexes.
+     *
+     * @return boolean
+     */
+    public function supportsPartialIndexes()
+    {
+        return true;
+    }
+
     /**
      * {@inheritDoc}
      */

lib/Doctrine/DBAL/Schema/AbstractSchemaManager.php

@@ -819,6 +819,7 @@ abstract class AbstractSchemaManager
                     'unique' => $tableIndex['non_unique'] ? false : true,
                     'primary' => $tableIndex['primary'],
                     'flags' => isset($tableIndex['flags']) ? $tableIndex['flags'] : array(),
+                    'where' => isset($tableIndex['where']) ? $tableIndex['where'] : null,
                 );
             } else {
                 $result[$keyName]['columns'][] = $tableIndex['column_name'];
@@ -841,7 +842,7 @@ abstract class AbstractSchemaManager
             }
 
             if ( ! $defaultPrevented) {
-                $index = new Index($data['name'], $data['columns'], $data['unique'], $data['primary'], $data['flags']);
+                $index = new Index($data['name'], $data['columns'], $data['unique'], $data['primary'], $data['flags'], $data['where']);
             }
 
             if ($index) {

lib/Doctrine/DBAL/Schema/Index.php

@@ -49,20 +49,29 @@ class Index extends AbstractAsset implements Constraint
      */
     protected $_flags = array();
 
+    /**
+     * Platform specific condition for partial indexes
+     *
+     * @var string|null
+     */
+    protected $_where = null;
+
     /**
      * @param string   $indexName
      * @param string[] $columns
      * @param boolean  $isUnique
      * @param boolean  $isPrimary
      * @param string[] $flags
+     * @param string|null $where
      */
-    public function __construct($indexName, array $columns, $isUnique = false, $isPrimary = false, array $flags = array())
+    public function __construct($indexName, array $columns, $isUnique = false, $isPrimary = false, array $flags = array(), $where = null)
     {
         $isUnique = $isUnique || $isPrimary;
 
         $this->_setName($indexName);
         $this->_isUnique = $isUnique;
         $this->_isPrimary = $isPrimary;
+        $this->_where = $where;
 
         foreach ($columns as $column) {
             $this->_addColumn($column);
@@ -199,7 +208,9 @@ class Index extends AbstractAsset implements Constraint
         $sameColumns = $this->spansColumns($other->getColumns());
 
         if ($sameColumns) {
-            if ( ! $this->isUnique() && !$this->isPrimary()) {
+            if ($other->getWhere() != $this->getWhere()) {
+                return false;
+            } elseif ( ! $this->isUnique() && !$this->isPrimary()) {
                 // this is a special case: If the current key is neither primary or unique, any uniqe or
                 // primary key will always have the same effect for the index and there cannot be any constraint
                 // overlaps. This means a primary or unique index can always fulfill the requirements of just an
@@ -232,7 +243,7 @@ class Index extends AbstractAsset implements Constraint
             return false;
         }
 
-        if ($this->spansColumns($other->getColumns()) && ($this->isPrimary() || $this->isUnique())) {
+        if ($this->spansColumns($other->getColumns()) && ($this->isPrimary() || $this->isUnique()) && $this->getWhere() == $other->getWhere()) {
             return true;
         }
 
@@ -288,4 +299,13 @@ class Index extends AbstractAsset implements Constraint
     {
         unset($this->_flags[strtolower($flag)]);
     }
+
+    /**
+     * Returns the where condition for partial indexes, if any
+     * @return string|null
+     */
+    public function getWhere()
+    {
+        return $this->_where;
+    }
 }

lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php

@@ -239,7 +239,8 @@ class PostgreSqlSchemaManager extends AbstractSchemaManager
                             'key_name' => $row['relname'],
                             'column_name' => trim($colRow['attname']),
                             'non_unique' => !$row['indisunique'],
-                            'primary' => $row['indisprimary']
+                            'primary' => $row['indisprimary'],
+                            'where' => $row['where'],
                         );
                     }
                 }

lib/Doctrine/DBAL/Schema/Table.php

@@ -146,10 +146,11 @@ class Table extends AbstractAsset
      * @param array       $columnNames
      * @param string|null $indexName
      * @param array       $flags
+     * @param string|null $where
      *
      * @return self
      */
-    public function addIndex(array $columnNames, $indexName = null, array $flags = array())
+    public function addIndex(array $columnNames, $indexName = null, array $flags = array(), $where = null)
     {
         if ($indexName == null) {
             $indexName = $this->_generateIdentifierName(
@@ -157,7 +158,7 @@ class Table extends AbstractAsset
             );
         }
 
-        return $this->_addIndex($this->_createIndex($columnNames, $indexName, false, false, $flags));
+        return $this->_addIndex($this->_createIndex($columnNames, $indexName, false, false, $flags, $where));
     }
 
     /**
@@ -192,10 +193,11 @@ class Table extends AbstractAsset
     /**
      * @param array       $columnNames
      * @param string|null $indexName
+     * @param string|null $where
      *
      * @return self
      */
-    public function addUniqueIndex(array $columnNames, $indexName = null)
+    public function addUniqueIndex(array $columnNames, $indexName = null, $where = null)
     {
         if ($indexName === null) {
             $indexName = $this->_generateIdentifierName(
@@ -203,7 +205,7 @@ class Table extends AbstractAsset
             );
         }
 
-        return $this->_addIndex($this->_createIndex($columnNames, $indexName, true, false));
+        return $this->_addIndex($this->_createIndex($columnNames, $indexName, true, false, array(), $where));
     }
 
     /**
@@ -277,12 +279,13 @@ class Table extends AbstractAsset
      * @param boolean $isUnique
      * @param boolean $isPrimary
      * @param array   $flags
+     * @param string|null $where
      *
      * @return Index
      *
      * @throws SchemaException
      */
-    private function _createIndex(array $columnNames, $indexName, $isUnique, $isPrimary, array $flags = array())
+    private function _createIndex(array $columnNames, $indexName, $isUnique, $isPrimary, array $flags = array(), $where = null)
     {
         if (preg_match('(([^a-zA-Z0-9_]+))', $indexName)) {
             throw SchemaException::indexNameInvalid($indexName);
@@ -298,7 +301,7 @@ class Table extends AbstractAsset
             }
         }
 
-        return new Index($indexName, $columnNames, $isUnique, $isPrimary, $flags);
+        return new Index($indexName, $columnNames, $isUnique, $isPrimary, $flags, $where);
     }
 
     /**

tests/Doctrine/Tests/DBAL/Platforms/AbstractPlatformTestCase.php

@@ -136,6 +136,27 @@ abstract class AbstractPlatformTestCase extends \Doctrine\Tests\DbalTestCase
 
     abstract public function getGenerateUniqueIndexSql();
 
+    public function testGeneratesPartialIndexesSqlOnlyWhenSupportingPartialIndexes()
+    {
+        $where = 'test IS NULL AND test2 IS NOT NULL';
+        $indexDef = new \Doctrine\DBAL\Schema\Index('name', array('test', 'test2'), false, false, array(), $where);
+
+        $expected = ' WHERE ' . $where;
+
+        $actuals = array();
+        $actuals []= $this->_platform->getIndexDeclarationSQL('name', $indexDef);
+        $actuals []= $this->_platform->getUniqueConstraintDeclarationSQL('name', $indexDef);
+        $actuals []= $this->_platform->getCreateIndexSQL($indexDef, 'table');
+
+        foreach ($actuals as $actual) {
+            if ($this->_platform->supportsPartialIndexes()) {
+                $this->assertStringEndsWith($expected, $actual, 'WHERE clause should be present');
+            } else {
+                $this->assertStringEndsNotWith($expected, $actual, 'WHERE clause should NOT be present');
+            }
+        }
+    }
+
     public function testGeneratesForeignKeyCreationSql()
     {
         $fk = new \Doctrine\DBAL\Schema\ForeignKeyConstraint(array('fk_name_id'), 'other_table', array('id'), '');

tests/Doctrine/Tests/DBAL/Platforms/PostgreSqlPlatformTest.php

@@ -10,4 +10,9 @@ class PostgreSqlPlatformTest extends AbstractPostgreSqlPlatformTestCase
     {
         return new PostgreSqlPlatform;
     }
+
+    public function testSupportsPartialIndexes()
+    {
+        $this->assertTrue($this->_platform->supportsPartialIndexes());
+    }
 }

tests/Doctrine/Tests/DBAL/Platforms/SQLAnywherePlatformTest.php

@@ -845,6 +845,10 @@ class SQLAnywherePlatformTest extends AbstractPlatformTestCase
             'ALTER TABLE mytable RENAME quoted3 TO "baz"',
         );
     }
+    public function testGeneratesPartialIndexesSqlOnlyWhenSupportingPartialIndexes()
+    {
+        $this->markTestSkipped('Index declaration in statements like CREATE TABLE is not supported.');
+    }
 
     /**
      * @group DBAL-807

tests/Doctrine/Tests/DBAL/Platforms/SqlitePlatformTest.php

@@ -497,6 +497,11 @@ class SqlitePlatformTest extends AbstractPlatformTestCase
         );
     }
 
+    public function testSupportsPartialIndexes()
+    {
+        $this->assertTrue($this->_platform->supportsPartialIndexes());
+    }
+
     /**
      * @group DBAL-807
      */

tests/Doctrine/Tests/DBAL/Schema/IndexTest.php

@@ -79,6 +79,36 @@ class IndexTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue($idx1->isFullfilledBy($uniq));
     }
 
+    public function testFullfilledWithPartial()
+    {
+        $without = new Index('without', array('col1', 'col2'), true, false, array(), null);
+        $partial = new Index('partial', array('col1', 'col2'), true, false, array(), 'col1 IS NULL');
+        $another = new Index('another', array('col1', 'col2'), true, false, array(), 'col1 IS NULL');
+
+        $this->assertFalse($partial->isFullfilledBy($without));
+        $this->assertFalse($without->isFullfilledBy($partial));
+
+        $this->assertTrue($partial->isFullfilledBy($partial));
+
+        $this->assertTrue($partial->isFullfilledBy($another));
+        $this->assertTrue($another->isFullfilledBy($partial));
+    }
+
+    public function testOverrulesWithPartial()
+    {
+        $without = new Index('without', array('col1', 'col2'), true, false, array(), null);
+        $partial = new Index('partial', array('col1', 'col2'), true, false, array(), 'col1 IS NULL');
+        $another = new Index('another', array('col1', 'col2'), true, false, array(), 'col1 IS NULL');
+
+        $this->assertFalse($partial->overrules($without));
+        $this->assertFalse($without->overrules($partial));
+
+        $this->assertTrue($partial->overrules($partial));
+
+        $this->assertTrue($partial->overrules($another));
+        $this->assertTrue($another->overrules($partial));
+    }
+
     /**
      * @group DBAL-220
      */