Oracle Database Discussions

I have a situation where I would like to append data in one table to data in another (say A->B), using INSERT INTO. The two tables have the same field names, but several of the data types are inconsistent between the two. For example, some of the data fields in Table A are of data type "VarChar2", and corresponding fields in Table B are of "Date" type.

I am currently not able to run this to check the outcome to a problem with my database connection, but will this mismatch in data type cause an error or will it just cause a warning? Would the same be true of appending data of type "VarChar2" to data of type "Boolean", for example - i.e. if Boolean data is stored in a VarChar2 data type field, will this destroy the information, or is it preserved and revealed as Boolean when appended with a Boolean field in another table?

Many thanks