Introspect foreign key constraint deferrability on Oracle

src/Platforms/AbstractPlatform.php

@@ -1652,6 +1652,32 @@ public function getAdvancedForeignKeyOptionsSQL(ForeignKeyConstraint $foreignKey
         return $query;
     }
 
+    /**
+     * Returns the SQL fragment representing the deferrability of a constraint.
+     */
+    protected function getConstraintDeferrabilitySQL(ForeignKeyConstraint $foreignKey): string
+    {
+        $sql = '';
+
+        if ($foreignKey->hasOption('deferrable')) {
+            if ($foreignKey->getOption('deferrable') !== false) {
+                $sql .= ' DEFERRABLE';
+            } else {
+                $sql .= ' NOT DEFERRABLE';
+            }
+        }
+
+        if ($foreignKey->hasOption('deferred')) {
+            if ($foreignKey->getOption('deferred') !== false) {
+                $sql .= ' INITIALLY DEFERRED';
+            } else {
+                $sql .= ' INITIALLY IMMEDIATE';
+            }
+        }
+
+        return $sql;
+    }
+
     /**
      * Returns the given referential action in uppercase if valid, otherwise throws an exception.
      *

src/Platforms/OraclePlatform.php

@@ -483,17 +483,23 @@ public function getDropForeignKeySQL(string $foreignKey, string $table): string
     /** @internal The method should be only used from within the {@see AbstractPlatform} class hierarchy. */
     public function getAdvancedForeignKeyOptionsSQL(ForeignKeyConstraint $foreignKey): string
     {
-        $referentialAction = '';
+        $sql = '';
 
         if ($foreignKey->hasOption('onDelete')) {
             $referentialAction = $this->getForeignKeyReferentialActionSQL($foreignKey->getOption('onDelete'));
+
+            if ($referentialAction !== '') {
+                $sql .= ' ON DELETE ' . $referentialAction;
+            }
         }
 
-        if ($referentialAction !== '') {
-            return ' ON DELETE ' . $referentialAction;
+        $deferrabilitySQL = $this->getConstraintDeferrabilitySQL($foreignKey);
+
+        if ($deferrabilitySQL !== '') {
+            $sql .= $deferrabilitySQL;
         }
 
-        return '';
+        return $sql;
     }
 
     /** @internal The method should be only used from within the {@see AbstractPlatform} class hierarchy. */

src/Platforms/PostgreSQLPlatform.php

@@ -182,20 +182,10 @@ public function getAdvancedForeignKeyOptionsSQL(ForeignKeyConstraint $foreignKey
 
         $query .= parent::getAdvancedForeignKeyOptionsSQL($foreignKey);
 
-        if ($foreignKey->hasOption('deferrable')) {
-            if ($foreignKey->getOption('deferrable') !== false) {
-                $query .= ' DEFERRABLE';
-            } else {
-                $query .= ' NOT DEFERRABLE';
-            }
-        }
+        $deferrabilitySQL = $this->getConstraintDeferrabilitySQL($foreignKey);
 
-        if ($foreignKey->hasOption('deferred')) {
-            if ($foreignKey->getOption('deferred') !== false) {
-                $query .= ' INITIALLY DEFERRED';
-            } else {
-                $query .= ' INITIALLY IMMEDIATE';
-            }
+        if ($deferrabilitySQL !== '') {
+            $query .= $deferrabilitySQL;
         }
 
         return $query;

src/Schema/OracleSchemaManager.php

@@ -207,6 +207,8 @@ protected function _getPortableTableForeignKeysList(array $tableForeignKeys): ar
                     'foreign' => [],
                     'foreignTable' => $value['references_table'],
                     'onDelete' => $value['delete_rule'],
+                    'deferrable' => $value['deferrable'] === 'DEFERRABLE',
+                    'deferred' => $value['deferred'] === 'DEFERRED',
                 ];
             }
 
@@ -230,7 +232,11 @@ protected function _getPortableTableForeignKeyDefinition(array $tableForeignKey)
             $this->getQuotedIdentifierName($tableForeignKey['foreignTable']),
             $tableForeignKey['foreign'],
             $this->getQuotedIdentifierName($tableForeignKey['name']),
-            ['onDelete' => $tableForeignKey['onDelete']],
+            [
+                'onDelete' => $tableForeignKey['onDelete'],
+                'deferrable' => $tableForeignKey['deferrable'],
+                'deferred' => $tableForeignKey['deferred'],
+            ],
         );
     }
 
@@ -412,6 +418,8 @@ protected function selectForeignKeyColumns(string $databaseName, ?string $tableN
         $sql .= <<<'SQL'
                  ALC.CONSTRAINT_NAME,
                  ALC.DELETE_RULE,
+                 ALC.DEFERRABLE,
+                 ALC.DEFERRED,
                  COLS.COLUMN_NAME LOCAL_COLUMN,
                  COLS.POSITION,
                  R_COLS.TABLE_NAME REFERENCES_TABLE,

tests/Functional/Schema/ForeignKeyConstraintTest.php

@@ -311,7 +311,7 @@ public function testDeferrabilityIntrospection(array $options, array $expectedOp
 
         if ($platform instanceof SQLitePlatform) {
             self::markTestIncomplete('Not all combinations of options are currently properly introspected on SQLite.');
-        } elseif (! $platform instanceof PostgreSQLPlatform) {
+        } elseif (! $platform instanceof PostgreSQLPlatform && ! $platform instanceof OraclePlatform) {
             self::markTestSkipped(sprintf(
                 'Introspection of constraint deferrability is currently unsupported on %s.',
                 $platform::class,