Fixed issue #762

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 2.0.0 under development
 
+- Enh #762: Add methods `SchemaInterface::hasSchema()`, `SchemaInterface::hasTable()`, `SchemaInterface::hasView()` (@evil1)
 - Enh #820: Support `Traversable` values for `AbstractDMLQueryBuilder::batchInsert()` method with empty columns (@Tigrov)
 - Enh #815: Refactor `Query::column()` method (@Tigrov) 
 - Enh #816: Allow scalar values for `$columns` parameter of `Query::select()` and `Query::addSelect()` methods (@Tigrov)

src/Schema/AbstractSchema.php

@@ -574,4 +574,34 @@ public function getViewNames(string $schema = '', bool $refresh = false): array
 
         return (array) $this->viewNames[$schema];
     }
+
+    /**
+     * @throws Throwable
+     */
+    public function hasTable(string $tableName, string $schema = '', bool $refresh = false): bool
+    {
+        $tables = $this->getTableNames($schema, $refresh);
+
+        return in_array($tableName, $tables);
+    }
+
+    /**
+     * @throws Throwable
+     */
+    public function hasSchema(string $schema, bool $refresh = false): bool
+    {
+        $schemas = $this->getSchemaNames($refresh);
+
+        return in_array($schema, $schemas);
+    }
+
+    /**
+     * @throws Throwable
+     */
+    public function hasView(string $viewName, string $schema = '', bool $refresh = false): bool
+    {
+        $views = $this->getViewNames($schema, $refresh);
+
+        return in_array($viewName, $views);
+    }
 }

src/Schema/SchemaInterface.php

@@ -416,4 +416,41 @@ public function enableCache(bool $value): void;
      * @return array All view names in the database.
      */
     public function getViewNames(string $schema = '', bool $refresh = false): array;
+
+    /**
+     * Determines if a specified table exists in the database.
+     *
+     * @param string $tableName The table name to search for
+     * @param string $schema The schema of the tables. Defaults to empty string, meaning the current or default schema
+     * name. If not empty, the table will be searched in the specified schema.
+     * @param bool $refresh Whether to fetch the latest available table names. If this is false, view names fetched
+     * before (if available) will be returned.
+     *
+     * @return bool Whether table exists.
+     */
+    public function hasTable(string $tableName, string $schema = '', bool $refresh = false): bool;
+
+    /**
+     * Determines if a specified schema exists in the database.
+     *
+     * @param string $schema The schema name to search for
+     * @param bool $refresh Whether to fetch the latest available schema names. If this is false, view names fetched
+     * before (if available) will be returned.
+     *
+     * @return bool Whether schema exists.
+     */
+    public function hasSchema(string $schema, bool $refresh = false): bool;
+
+    /**
+     * Determines if a specified view exists in the database.
+     *
+     * @param string $viewName The view name to search for
+     * @param string $schema The schema of the tables. Defaults to empty string, meaning the current or default schema
+     * name. If not empty, the table will be searched in the specified schema.
+     * @param bool $refresh Whether to fetch the latest available view names. If this is false, view names fetched
+     * before (if available) will be returned.
+     *
+     * @return bool Whether view exists.
+     */
+    public function hasView(string $viewName, string $schema = '', bool $refresh = false): bool;
 }

tests/Common/CommonSchemaTest.php

@@ -405,6 +405,28 @@ public function testGetTableNames(array $pdoAttributes): void
         $db->close();
     }
 
+    public function testHasTable(): void
+    {
+        $db = $this->getConnection(true);
+
+        $schema = $db->getSchema();
+
+        $this->assertTrue($schema->hasTable('customer'));
+        $this->assertTrue($schema->hasTable('category'));
+        $this->assertFalse($schema->hasTable('no_such_table'));
+
+        $this->assertTrue($schema->hasTable('customer', '', true));
+        $this->assertTrue($schema->hasTable('category', '', true));
+        $this->assertFalse($schema->hasTable('no_such_table', '', true));
+
+        if ($db->getDriverName() !== 'sqlite') {
+            $this->assertFalse($schema->hasTable('customer', 'no_such_schema', true));
+            $this->assertFalse($schema->hasTable('category', 'no_such_schema', true));
+        }
+
+        $db->close();
+    }
+
     /**
      * @dataProvider \Yiisoft\Db\Tests\Provider\SchemaProvider::tableSchema
      */
@@ -482,6 +504,25 @@ public function testGetViewNames(): void
         $db->close();
     }
 
+    public function testHasView(): void
+    {
+        $db = $this->getConnection(true);
+
+        $schema = $db->getSchema();
+
+        $this->assertTrue($schema->hasView('animal_view'));
+        $this->assertFalse($schema->hasView('no_such_view'));
+
+        $this->assertTrue($schema->hasView('animal_view', '', true));
+        $this->assertFalse($schema->hasView('no_such_view', '', true));
+
+        if ($db->getDriverName() !== 'sqlite') {
+            $this->assertFalse($schema->hasView('animal_view', 'no_such_schema', true));
+        }
+
+        $db->close();
+    }
+
     public function testNegativeDefaultValues(): void
     {
         $db = $this->getConnection(true);

tests/Db/Schema/SchemaTest.php

@@ -202,6 +202,20 @@ public function testGetSchemaNamesWithSchema(): void
         $this->assertSame(['dbo', 'public'], $schema->getSchemaNames());
     }
 
+    public function testHasSchema(): void
+    {
+        $db = $this->getConnection();
+
+        $schema = $db->getSchema();
+        Assert::setInaccessibleProperty($schema, 'schemaNames', ['dbo', 'public']);
+
+        $this->assertTrue($schema->hasSchema('dbo'));
+        $this->assertTrue($schema->hasSchema('public'));
+        $this->assertFalse($schema->hasSchema('no_such_schema'));
+
+        $db->close();
+    }
+
     /**
      * @throws NotSupportedException
      */