database examples compatible with sqlite

Real life use cases.

Commandline SQL changed to apply to SQLite as well.  Unfortunately maths
requires v3.35, so keep psql there even though it requires user setup.

diff --git a/barcat b/barcat
index 2a931c6a55fb92f6be6e09ea13c5a5d45234115e..7fc7f66ca177ea17fb56c7715d90d66241fe602f 100755 (executable)
--- a/barcat
+++ b/barcat
@@ -650,14 +650,21 @@ Number of HTTP requests per day:
 
     cat httpd/access.log | cut -d\  -f4 | cut -d: -f1 | uniq -c | barcat
 
-Any kind of database query with counts, preserving returned alignment:
+Any kind of database query results, preserving returned alignment:
 
-    echo 'SELECT count(*),schemaname FROM pg_tables GROUP BY 2' |
+    echo 'SELECT sin(value * .1) FROM generate_series(0, 30) value' |
     psql -t | barcat -u
 
-In PostgreSQL from within the client:
+In PostgreSQL from within the client; a fancy C<\dt+> perhaps:
 
-    > SELECT sin(generate_series(0, 3, .1)) \g |barcat
+    > SELECT schemaname, relname, pg_total_relation_size(relid)
+      FROM pg_statio_user_tables ORDER BY idx_blks_hit
+      \g |barcat -uHf+
+
+Same thing in SQLite (requires the sqlite3 client):
+
+    > .once |barcat -Hf+
+    > SELECT name, sum(pgsize) FROM dbstat GROUP BY 1;
 
 Earthquakes worldwide magnitude 1+ in the last 24 hours: