SQLite - Commands

This chapter will take you through simple and useful commands used by SQLite programmers. These commands are called SQLite dot commands and exception with these commands is that they should not be terminated by a semi-colon (;).

Let's start with typing a simple sqlite3 command at command prompt which will provide you with SQLite command prompt where you will issue various SQLite commands.

$sqlite3
SQLite version 3.3.6
Enter ".help" for instructions
sqlite>

For a listing of the available dot commands, you can enter ".help" any time. For example −

sqlite>.help

The above command will display a list of various important SQLite dot commands, which are listed in the following table.

Let's try .show command to see default setting for your SQLite command prompt.

sqlite>.show
     echo: off
  explain: off
  headers: off
     mode: column
nullvalue: ""
   output: stdout
separator: "|"
    width:
sqlite>

Make sure there is no space in between sqlite> prompt and dot command, otherwise it will not work.

Formatting Output

You can use the following sequence of dot commands to format your output.

sqlite>.header on
sqlite>.mode column
sqlite>.timer on
sqlite>

The above setting will produce the output in the following format.

ID          NAME        AGE         ADDRESS     SALARY
----------  ----------  ----------  ----------  ----------
1           Paul        32          California  20000.0
2           Allen       25          Texas       15000.0
3           Teddy       23          Norway      20000.0
4           Mark        25          Rich-Mond   65000.0
5           David       27          Texas       85000.0
6           Kim         22          South-Hall  45000.0
7           James       24          Houston     10000.0
CPU Time: user 0.000000 sys 0.000000

The sqlite_master Table

The master table holds the key information about your database tables and it is called sqlite_master. You can see its schema as follows −

sqlite>.schema sqlite_master

This will produce the following result.

CREATE TABLE sqlite_master (
   type text,
   name text,
   tbl_name text,
   rootpage integer,
   sql text
);