I am creating a program that is connected to an access database. My question is, if in the future the user wants to add some new fields to the database, when I install the new version of the program how will I update the modified database with the information that the user has already entered.
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Updating database design
- Thread starter bjarvis
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NO, data will not automatically transfer from one database to another!
1) If you are updating the code elements and maintaining the same database (and they are not the same file, e.g. a single Access database with both forms and data):
When you install a new version of your program, you also run a database update routine, that modifies the existing tables by adding new fields. These fields must either have a default value or allow nulls.
2) If you must replace the physical database, then:
First rename it the database.
Move your new empty database to the directory.
Run a series of queries to append all of the records from each data table in the old database to the new one. (If referential integrity is set, you will have to do this in a specific order)
1) If you are updating the code elements and maintaining the same database (and they are not the same file, e.g. a single Access database with both forms and data):
When you install a new version of your program, you also run a database update routine, that modifies the existing tables by adding new fields. These fields must either have a default value or allow nulls.
2) If you must replace the physical database, then:
First rename it the database.
Move your new empty database to the directory.
Run a series of queries to append all of the records from each data table in the old database to the new one. (If referential integrity is set, you will have to do this in a specific order)
Sorry, I went home shortly after writing my last bit. If I had have been here I would have written NO too!
As hirick says, you will need to import the existing data into the modified tables.
If you have a copy of Access this can help - attach the original tables, then write an append query to copy the data into the relevant fields.
If any of your new fields do not allow nulls you will have to provide some default data.
As hirick says, you will need to import the existing data into the modified tables.
If you have a copy of Access this can help - attach the original tables, then write an append query to copy the data into the relevant fields.
If any of your new fields do not allow nulls you will have to provide some default data.
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