Functions to coerce an object to a data model if possible.
as.data_model(x)Object (list or data frame) to be coerced to data model object
If possible it returns a data model object. It is a list of data frames with at least the following columns:
A name of the column in a table
A boolean value indicating this column is a primary key or NA.
A character string with a referenced table name. Not being NA means the column is a foreign key.
Function accepts a data frame with columns info. Data frame must have 'table' and 'column' elements. Optional element 'key' (boolean) marks a column as a primary key. Optional element 'ref' (character string) defines referenced table name. Optional element 'ref_col' (character string) defines a column in a referenced table name primary key (only necessery when referenced table has a compound primary key).