I believe the behavior is correct. Let's go through all the cases you described.

First of all, the default varchar (that is one without lenght) has syntax: "varchar" or "character varying". You can write it this way in "Type" field and you get no error:

tests=> CREATE TABLE def_varchar (
tests(>    id int  NOT NULL,
tests(>    code varchar  NOT NULL,
tests(>    CONSTRAINT def_varchar_pk PRIMARY KEY (id)
tests(> );
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "def_varchar_pk" for table "def_varchar"
CREATE TABLE

Then, if you try either "varchar()" or "varchar(%)", both Vertabelo and PostgreSQL will raise an error:

tests=> CREATE TABLE def_varchar (
tests(>    id int  NOT NULL,
tests(>    code varchar()  NOT NULL,
tests(>    CONSTRAINT def_varchar_pk PRIMARY KEY (id)
tests(> );
ERROR:  syntax error at or near ")"
LINE 3:    code varchar()  NOT NULL,
                        ^

tests=> CREATE TABLE def_varchar (
tests(>    id int  NOT NULL,
tests(>    code varchar(%)  NOT NULL,
tests(>    CONSTRAINT def_varchar_pk PRIMARY KEY (id)
tests(> );
ERROR:  syntax error at or near "%"
LINE 3:    code varchar(%)  NOT NULL,
                        ^

Please note that the list of data types is only a helper to choose the most common ones. You can provide any text you want into the "Type" field. Vertabelo either warns you or raises an error if it doesn't recognize the type, but you can ignore it if you like.

Hope this helps.

Hello,

Please send your XML file to our email address: contact@vertabelo.com

Best regards,

Adam

Yes, you can do this with 3 clicks. Just go to "Documents", then right-click on the model you want to duplicate and choose "Make a copy" option.

Another way to do the same is to select the model as before and click on "copy" icon on the top bar.

Vertabelo operates on a physical model, not logical. You need to create an association table on your own.