[sqlite] Opening database file from within SQLite command-line shell

I'm using the SQLite Command Line Shell. As documented, I can open a database by supplying it as an argument to the executable:

sqlite3 data.db

I cannot figure out how to open a database file from within the tool after having invoked it without supplying the file as a command-line argument (if I, say, double-click sqlite3.exe in Windows).

What is the command within the SQLite shell tool to specify a database file?

create different db files using
      >sqlite3 test1.db
sqlite> create table test1 (name text);
sqlite> insert into test1 values('sourav');
sqlite>.exit
      >sqlite3 test2.db
sqlite> create table test2 (eid integer);
sqlite> insert into test2 values (6);
sqlite>.exit
      >sqlite
SQLite version 3.8.5 2014-06-04 14:06:34
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> .open test1.db
sqlite> select * from test1;
sourav
sqlite> .open test2.db
sqlite> select * from test1;
Error: no such table: test1
sqlite> select * from test2;
6
sqlite> .exit
      >

Thank YOU.

I think the simplest way to just open a single database and start querying is:

sqlite> .open "test.db"
sqlite> SELECT * FROM table_name ... ;

Notice: This works only for versions 3.8.2+

The same way you do it in other db system, you can use the name of the db for identifying double named tables. unique tablenames can used directly.

select * from ttt.table_name;

or if table name in all attached databases is unique

select * from my_unique_table_name;

But I think the of of sqlite-shell is only for manual lookup or manual data manipulation and therefor this way is more inconsequential

normally you would use sqlite-command-line in a script

Older SQLite command-line shells (sqlite3.exe) do not appear to offer the .open command or any readily identifiable alternative.

Although I found no definitive reference it seems that the .open command was introduced around version 3.15. The SQLite Release History first mentions the .open command with 2016-10-14 (3.15.0).

I wonder why no one was able to get what the question actually asked. It stated What is the command within the SQLite shell tool to specify a database file?

A sqlite db is on my hard disk E:\ABCD\efg\mydb.db. How do I access it with sqlite3 command line interface? .open E:\ABCD\efg\mydb.db does not work. This is what question asked.

I found the best way to do the work is

• copy-paste all your db files in 1 directory (say E:\ABCD\efg\mydbs)
• switch to that directory in your command line
• now open sqlite3 and then .open mydb.db

This way you can do the join operation on different tables belonging to different databases as well.

You can simply specify the database file name in the command line:

bash-3.2 # sqlite3 UserDb.sqlite
SQLite version 3.16.2 2017-01-06 16:32:41
Enter ".help" for usage hints.

sqlite> .databases
main: /db/UserDb.sqlite

sqlite> .tables
accountLevelSettings  genres               syncedThumbs
collectionActivity    recordingFilter      thumbs
contentStatus         syncedContentStatus 

sqlite> select count(*) from genres;
10

Moreover, you can execute your query from the command line:

bash-3.2 # sqlite3 UserDb.sqlite 'select count(*) from genres'
10

You could attach another database file from the SQLite shell:

sqlite> attach database 'RelDb.sqlite' as RelDb;

sqlite> .databases
main: /db/UserDb.sqlite
RelDb: /db/RelDb_1.sqlite

sqlite> .tables
RelDb.collectionRelationship  contentStatus               
RelDb.contentRelationship     genres                      
RelDb.leagueRelationship      recordingFilter             
RelDb.localizedString         syncedContentStatus         
accountLevelSettings          syncedThumbs                
collectionActivity            thumbs                      

The tables from this 2nd database will be accessible via prefix of the database:

sqlite> select count(*) from RelDb.localizedString;
2442

But who knows how to specify multiple database files from the command line to execute the query from the command line?

The command within the Sqlite shell to open a database is .open

The syntax is,

sqlite> .open dbasename.db

If it is a new database that you would like to create and open, it is

sqlite> .open --new dbasename.db

If the database is existing in a different folder, the path has to be mentioned like this:

sqlite> .open D:/MainFolder/SubFolder/...database.db

In Windows Command shell, you should use '\' to represent a directory, but in SQLite directories are represented by '/'. If you still prefer to use the Windows notation, you should use an escape sequence for every '\'