Hi Kai,
By Models if you mean HANA Artifacts in terms of Attribute View, Analytic Views,etc. these are available under the SCHEMA _SYS_BIC as Column Views, you can import that Schema.
However I will suggest you to use the functionality provided by HANA Studio for importing/exporting models. Quick Launch->Import(Under Content)->SAP HANA Content->Developer Mode/Support Mode. From here you can choose which models to import/export.
Have you tried the SAP HANA Reference[http://help.sap.com/hana/html/sql_import.html]
It will give details about the SQL statements that you can use.
Also if you are trying to import/export models into/from a local machine(client) you cannot use SQL. You will have to use HANA Studio functionality.
BR/Shreepad