An apparatus, a method, and a storage medium for database query. The apparatus, method, and storage medium are configured to: determine a syntax tree corresponding to an SQL query statement includes a preset subtree, wherein the preset subtree is used to indicate a query mode for querying vector data; determine a query mode according to the preset subtree and the SQL query statement; query data in a database based on the query mode to determine query results. By using an SQL query statement including a preset subtree to query a vector database, to realize an efficient approximate query, so as to avoid high access costs caused by accessing the database by using an API. Moreover, it can reduce user's understanding costs on unstructured query.