Merge pull request #18297 from frappe/mergify/bp/version-14-hotfix/pr-18262

fix: correct index syncing (backport #18262)

frappe/database/mariadb/database.py

@@ -301,6 +301,7 @@ class MariaDBDatabase(MariaDBConnectionUtil, MariaDBExceptionUtil, Database):
 				where table_name="{table_name}"
 					and column_name=columns.column_name
 					and NON_UNIQUE=1
+					and Seq_in_index = 1
 					limit 1
 			), 0) as 'index',
 			column_key = 'UNI' as 'unique'
@@ -319,6 +320,37 @@ class MariaDBDatabase(MariaDBConnectionUtil, MariaDBExceptionUtil, Database):
 			)
 		)
 
+	def get_column_index(
+		self, table_name: str, fieldname: str, unique: bool = False
+	) -> frappe._dict | None:
+		"""Check if column exists for a specific fields in specified order.
+
+		This differs from db.has_index because it doesn't rely on index name but columns inside an
+		index.
+		"""
+
+		indexes = self.sql(
+			f"""SHOW INDEX FROM `{table_name}`
+				WHERE Column_name = "{fieldname}"
+					AND Seq_in_index = 1
+					AND Non_unique={int(not unique)}
+				""",
+			as_dict=True,
+		)
+
+		# Same index can be part of clustered index which contains more fields
+		# We don't want those.
+		for index in indexes:
+			clustered_index = self.sql(
+				f"""SHOW INDEX FROM `{table_name}`
+					WHERE Key_name = "{index.Key_name}"
+						AND Seq_in_index = 2
+					""",
+				as_dict=True,
+			)
+			if not clustered_index:
+				return index
+
 	def add_index(self, doctype: str, fields: list, index_name: str = None):
 		"""Creates an index with given fields if not already created.
 		Index name will be `fieldname1_fieldname2_index`"""

frappe/database/mariadb/schema.py

@@ -84,45 +84,23 @@ class MariaDBTable(DBTable):
 
 		for col in self.add_index:
 			# if index key does not exists
-			if not frappe.db.has_index(self.table_name, col.fieldname + "_index"):
+			if not frappe.db.get_column_index(self.table_name, col.fieldname, unique=False):
 				add_index_query.append(f"ADD INDEX `{col.fieldname}_index`(`{col.fieldname}`)")
 
 		for col in self.drop_index + self.drop_unique:
-			if col.fieldname != "name":  # primary key
-				current_column = self.current_columns.get(col.fieldname.lower())
-				unique_constraint_changed = current_column.unique != col.unique
-				if unique_constraint_changed and not col.unique:
-					# nosemgrep
-					unique_index_record = frappe.db.sql(
-						"""
-						SHOW INDEX FROM `{}`
-						WHERE Key_name=%s
-						AND Non_unique=0
-					""".format(
-							self.table_name
-						),
-						(col.fieldname),
-						as_dict=1,
-					)
-					if unique_index_record:
-						drop_index_query.append(f"DROP INDEX `{unique_index_record[0].Key_name}`")
-				index_constraint_changed = current_column.index != col.set_index
-				# if index key exists
-				if index_constraint_changed and not col.set_index:
-					# nosemgrep
-					index_record = frappe.db.sql(
-						"""
-						SHOW INDEX FROM `{}`
-						WHERE Key_name=%s
-						AND Non_unique=1
-					""".format(
-							self.table_name
-						),
-						(col.fieldname + "_index"),
-						as_dict=1,
-					)
-					if index_record:
-						drop_index_query.append(f"DROP INDEX `{index_record[0].Key_name}`")
+			if col.fieldname == "name":
+				continue
+
+			current_column = self.current_columns.get(col.fieldname.lower())
+			unique_constraint_changed = current_column.unique != col.unique
+			if unique_constraint_changed and not col.unique:
+				if unique_index := frappe.db.get_column_index(self.table_name, col.fieldname, unique=True):
+					drop_index_query.append(f"DROP INDEX `{unique_index.Key_name}`")
+
+			index_constraint_changed = current_column.index != col.set_index
+			if index_constraint_changed and not col.set_index:
+				if index_record := frappe.db.get_column_index(self.table_name, col.fieldname, unique=False):
+					drop_index_query.append(f"DROP INDEX `{index_record.Key_name}`")
 
 		try:
 			for query_parts in [add_column_query, modify_column_query, add_index_query, drop_index_query]: