Added Hyperf\Database\Schema\Schema::getForeignKeys(). (#7059)

Co-authored-by: 李铭昕 <715557344@qq.com>

Author: zds-s

src/Query/Processors/PostgresProcessor.php

@@ -79,4 +79,38 @@ public function processIndexes(array $results): array
             ];
         }, $results);
     }
+
+    /**
+     * Process the results of a foreign keys query.
+     */
+    public function processForeignKeys(array $results): array
+    {
+        return array_map(function ($result) {
+            $result = (object) $result;
+
+            return [
+                'name' => $result->name,
+                'columns' => explode(',', $result->columns),
+                'foreign_schema' => $result->foreign_schema,
+                'foreign_table' => $result->foreign_table,
+                'foreign_columns' => explode(',', $result->foreign_columns),
+                'on_update' => match (strtolower($result->on_update)) {
+                    'a' => 'no action',
+                    'r' => 'restrict',
+                    'c' => 'cascade',
+                    'n' => 'set null',
+                    'd' => 'set default',
+                    default => null,
+                },
+                'on_delete' => match (strtolower($result->on_delete)) {
+                    'a' => 'no action',
+                    'r' => 'restrict',
+                    'c' => 'cascade',
+                    'n' => 'set null',
+                    'd' => 'set default',
+                    default => null,
+                },
+            ];
+        }, $results);
+    }
 }

src/Schema/Grammars/PostgresGrammar.php

@@ -509,6 +509,32 @@ public function typeMultiLineString(Fluent $column)
         return $this->formatPostGisType('multilinestring', $column);
     }
 
+    /**
+     * Compile the query to determine the foreign keys.
+     */
+    public function compileForeignKeys(string $schema, string $table): string
+    {
+        return sprintf(
+            'select c.conname as name, '
+            . "string_agg(la.attname, ',' order by conseq.ord) as columns, "
+            . 'fn.nspname as foreign_schema, fc.relname as foreign_table, '
+            . "string_agg(fa.attname, ',' order by conseq.ord) as foreign_columns, "
+            . 'c.confupdtype as on_update, c.confdeltype as on_delete '
+            . 'from pg_constraint c '
+            . 'join pg_class tc on c.conrelid = tc.oid '
+            . 'join pg_namespace tn on tn.oid = tc.relnamespace '
+            . 'join pg_class fc on c.confrelid = fc.oid '
+            . 'join pg_namespace fn on fn.oid = fc.relnamespace '
+            . 'join lateral unnest(c.conkey) with ordinality as conseq(num, ord) on true '
+            . 'join pg_attribute la on la.attrelid = c.conrelid and la.attnum = conseq.num '
+            . 'join pg_attribute fa on fa.attrelid = c.confrelid and fa.attnum = c.confkey[conseq.ord] '
+            . "where c.contype = 'f' and tc.relname = %s and tn.nspname = %s "
+            . 'group by c.conname, fn.nspname, fc.relname, c.confupdtype, c.confdeltype',
+            $this->quoteString($table),
+            $this->quoteString($schema)
+        );
+    }
+
     /**
      * Create the column definition for a char type.
      *

src/Schema/PostgresBuilder.php

@@ -214,6 +214,20 @@ public function getColumnListing($table): array
         return $this->connection->getPostProcessor()->processColumnListing($results);
     }
 
+    /**
+     * Get the foreign keys for a given table.
+     */
+    public function getForeignKeys(string $table): array
+    {
+        [$schema, $table] = $this->parseSchemaAndTable($table);
+
+        $table = $this->connection->getTablePrefix() . $table;
+
+        return $this->connection->getPostProcessor()->processForeignKeys(
+            $this->connection->selectFromWriteConnection($this->grammar->compileForeignKeys($schema, $table))
+        );
+    }
+
     /**
      * Get the column type listing for a given table.
      */

tests/Cases/SchemaBuilderTest.php

@@ -217,4 +217,24 @@ public function index(): void
         $this->assertTrue(collect($indexes)->contains(fn ($index) => $index['columns'] === ['id'] && $index['primary']));
         $this->assertTrue(collect($indexes)->contains('name', 'articles_body_title_fulltext'));
     }
+
+    public function testGetForeignKeys()
+    {
+        Schema::create('users_copy', function (Blueprint $table) {
+            $table->id();
+        });
+
+        Schema::create('posts_copy', function (Blueprint $table) {
+            $table->foreignId('user_id')->nullable()->constrained('users_copy')->cascadeOnUpdate()->nullOnDelete();
+        });
+
+        $foreignKeys = Schema::getForeignKeys('posts_copy');
+
+        $this->assertCount(1, $foreignKeys);
+        $this->assertTrue(collect($foreignKeys)->contains(
+            fn ($foreign) => $foreign['columns'] === ['user_id']
+                && $foreign['foreign_table'] === 'users_copy' && $foreign['foreign_columns'] === ['id']
+                && $foreign['on_update'] === 'cascade' && $foreign['on_delete'] === 'set null'
+        ));
+    }
 }