Support multiple databases / tables

[kennytm]

Feature Request

Describe your feature request related problem:

Support backing up multiple tables in a single command without needing the --backupts trick.

Describe the feature you'd like:

A simplified version of #173. We support the following commands to backup/restore multiple databases or tables.

./br backup database --db firstdb --db seconddb 
#                                 ^~~~~~~~~~~~~
./br backup table --???? 'firstdb.firsttable' --???? '`second.db`.`2,tbl`'

Because the table name can contain a ., we need to support quoting by `.

Unresolved question:

• Should we change the behavior of database --db 'db1,db2'? (currently backing up a single database named "db1,db2"
• Should we change the behavior of database --db '`db`'? (currently backing up a single database named "`db`"
• What should the --???? parameter be named?
• Should we keep the table --db db1 --table tbl1 form?
• Do we want to support table --???? 'db1.tbl1,db2.tbl2'?
• Do we want to support table --db db1 --???? tbl1 --???? tbl2?
• Do we want to support table --db db1 --db db2 --???? tbl1 --???? tbl2?
• Should we support ANSI quotes table --???? '"db1,db2"."tbl1,tbl2"'?
• Should we reject if the inputs aren't proper identifiers table --???? '!@#$.%^&*'?

Describe alternatives you've considered:

Don't support this and go straight to #173.

Teachability, Documentation, Adoption, Migration Strategy:

If we decide to name --???? as --table we'll need to rewrite all documentations.

[3pointer]

I suggest add new flag like --dbs and --tables to backup mutliple tables

[IANTHEREAL]

My suggestions are based on two principles

• The simpler the better, let the user choose as little as possible while keeping it as easy to use
• Be consistent with other tools, do not design separately

• Should we change the behavior of database --db 'db1,db2'? (currently backing up a single database named "db1,db2"
• Should we change the behavior of database --db '`db`'? (currently backing up a single database named "`db`"
• What should the --???? parameter be named? **I suggest tables **
• Should we keep the table --db db1 --table tbl1 form? ** it is not clear **
• Do we want to support table --???? 'db1.tbl1,db2.tbl2'?
• Do we want to support table --db db1 --???? tbl1 --???? tbl2?
• Do we want to support table --db db1 --db db2 --???? tbl1 --???? tbl2?
• Should we support ANSI quotes table --???? '"db1,db2"."tbl1,tbl2"'?
• Should we reject if the inputs aren't proper identifiers table --???? '!@#$.%^&*'?

[kennytm]

@3pointer If we don't convert --db 'db1,db2' to --db db1 --db db2, adding a new --dbs seems pointless.

@GregoryIan If we support --db db1 --db db2 --db db3 --tables tbl1 --tables tbl2 --tables tbl3 it means we back up 9 (3×3) tables. Does that match what you mean? And what do you mean by

• Should we keep the table --db db1 --table tbl1 form? ** it is not clear **

?

[IANTHEREAL]

one example: --db db1 --tables tbl1 --tables tbl2 -db db2 --tables tbl2 --db db3 --tables tbl3 , means to backupdb1.tbl1, db1.tbl2,db2.tbl2, db3.tbl3, can we achieve it？

[kennytm]

@GregoryIan No, --abc def-style arguments are unordered.

[kennytm]

we may want to make --db a --db b and --table a --table b an error, this currently confuses some users.