SQLite list ALL foreign keys in a database

With the SQLite shell, use the .schema instruction, and use GREP to filter lines containing REFERENCES.

From shell.c in the SQLite repository, today's version in the trunk, two queries:

SELECT sql
  FROM (
        SELECT sql sql, type type, tbl_name tbl_name, name name
          FROM sqlite_master
         UNION ALL
        SELECT sql, type, tbl_name, name
          FROM sqlite_temp_master
       )
 WHERE tbl_name LIKE shellstatic()
   AND type != 'meta'
   AND sql NOTNULL
 ORDER BY substr(type, 2, 1), name

and

SELECT sql
  FROM (
        SELECT sql sql, type type, tbl_name tbl_name, name name
          FROM sqlite_master
         UNION ALL
        SELECT sql, type, tbl_name, name
          FROM sqlite_temp_master
       )
 WHERE type != 'meta'
   AND sql NOTNULL
   AND name NOT LIKE 'sqlite_%'
 ORDER BY substr(type, 2, 1), name

The second one is probably what you are looking for.

It seems that all (or many) of the PRAGMA commands can be programatically selected with a little trick;

Usually the are called like:

PRAGMA table_info('my_table');
PRAGMA foreign_key_list('my_table');

But this can also be done:

SELECT * FROM pragma_table_info('my_table');
SELECT * FROM pragma_foreign_key_list('my_table');

And the schema can also be (more or less) obtained:

.schema pragma_table_info
/* pragma_table_info(cid,name,type,"notnull",dflt_value,pk) */;

.schema pragma_foreign_key_list
/* pragma_foreign_key_list(id,seq,"table","from","to",on_update,on_delete,"match") */

So, to get all the fks a JOIN between sqlite_master and pragma_foreign_key_list can do the trick:

SELECT 
    m.name
    , p.*
FROM
    sqlite_master m
    JOIN pragma_foreign_key_list(m.name) p ON m.name != p."table"
WHERE m.type = 'table'
ORDER BY m.name
;

Just take care, that some fields of pragma_foreign_key_list like table, from, ... must be quoted;