Techniques for object relational mapping in database technologies are described herein. According to one embodiment, in response to a query statement for accessing a relational database, a syntax tree is generated to represent semantic information of the query statement, where the query statement includes a wildcard parameter and is implemented as an object of a SQL. A data type of the wildcard parameter is predicted based on the semantic information obtained from the syntax tree in view of a structure representing the syntax tree. The predicted data type of the wildcard parameter is used to access the corresponding entry of the relational database. Other methods and apparatuses are also described.