1.7. SQLite creates a database

1.7.1. Grammar ¶

The basic syntax of the sqlite3 command is as follows:

$ sqlite3 DatabaseName.db 

In general, database names should be unique within RDBMS.

We can also use .open to create a new database file:

sqlite>.open test.db 

The above command creates the database file test.db, which is located in the same directory as the sqlite3 command.

The. Open command is also used to open an existing database. If the above command test.db If it exists, it will be opened directly, and if it does not exist, create it.

1.7.2. Example ¶

If you want to create a new database < testDB.db >, the SQLITE3 statement looks like this:

$ sqlite3 testDB.db SQLite version 3.7.15.2 2013-01-09 11:53:05 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> 

The above command will create a file in the current directory testDB.db . This file will be used as a database by the SQLite engine. If you have noticed that after the sqlite3 command successfully creates the database file, it provides a sqlite> Prompt.

Once the database is created, you can use SQLite’s .databases Command to check if it is in the database list, as follows:

sqlite>.databases seq name file --- --------------- ---------------------- 0 main /home/sqlite/testDB.db 

You can use SQLite .quit The command exits the sqlite prompt, as follows:

sqlite>.quit $ 

1.7.3. .dump command ¶

You can use SQLite from a command prompt .dump Click the command to export the complete database in a text file, as follows:

$sqlite3 testDB.db .dump > testDB.sql 

The above command will convert the entire testDB.db Put the contents of the database into the statement of SQLite and dump it to the ASCII text file testDB.sql Medium. You can recover from the generated testDB.sql in a simple way, as follows:

$sqlite3 testDB.db < testDB.sql 

At this time, the database is empty, once there are tables and data in the database, you can try the above two programs. Now, let’s move on to the next chapter.