postgres-db-diff 0.9.1

Postgres DB diff

Command line tool to compare two PostgreSQL databases. It is based on parsing psql meta commands output. Such as \dt for tables and \dv for views.

https://www.postgresql.org/docs/current/static/app-psql.html

How to install

There are two options:

1. Use any python package installing tool. Recommended pip.

2. Just copy/paste postgresdbdiff.py into your dir and run it using python postgresdbdiff.py

Usage

usage: postgresdbdiff.py [-h] --db1 DB1 --db2 DB2 [--diff-folder DIFF_FOLDER]

optional arguments:
  -h, --help            show this help message and exit
  --db1 DB1             First DB name
  --db2 DB2             Second DB name
  --diff-folder DIFF_FOLDER
                        Directory to output diffs

Example

Create two DBs. One using this SQL:

CREATE TABLE table_a (
  id INTEGER PRIMARY KEY,
  test_unique VARCHAR (100) UNIQUE,
  test_not_null VARCHAR (100) NOT NULL,
  test_checks INTEGER NOT NULL
);

CREATE TABLE table_b (
  id INTEGER PRIMARY KEY,
  table_a_id integer REFERENCES table_a (id)
);

CREATE TABLE table_c (
  id INTEGER PRIMARY KEY
);

CREATE VIEW view_a AS SELECT
  id, test_unique, 42 AS some_number
FROM table_a;

Other using this SQL:

CREATE TABLE table_a (
  id INTEGER PRIMARY KEY,
  test_unique VARCHAR (100),
  test_not_null VARCHAR (100),
  test_checks INTEGER NOT NULL CHECK (test_checks > 0)
);

CREATE TABLE table_b (
  id INTEGER PRIMARY KEY,
  table_a_no integer REFERENCES table_a (id)
);

CREATE VIEW view_a AS SELECT
  id, test_unique
FROM table_a;

Then run this command

python postgresdbdiff.py --db1 diff_a --db2 diff_b --diff-folder diffs

Output should be like this

TABLES: additional in "diff_a"
  table_c

TABLES: not matching
  table_a
  table_b

VIEWS: not matching
  view_a

And there should be the folder named diffs with files looking like this

# diffs/table_a.diff
--- TABLES.diff_a.table_a
+++ TABLES.diff_b.table_a
@@ -1,12 +1,13 @@
                          Table "public.table_a"
     Column     |          Type          | Collation | Nullable | Default
 ---------------+------------------------+-----------+----------+---------
  id            | integer                |           | not null |
  test_checks   | integer                |           | not null |
- test_not_null | character varying(100) |           | not null |
+ test_not_null | character varying(100) |           |          |
  test_unique   | character varying(100) |           |          |
 Indexes:
     "table_a_pkey" PRIMARY KEY, btree (id)
-    "table_a_test_unique_key" UNIQUE CONSTRAINT, btree (test_unique)
+Check constraints:
+    "table_a_test_checks_check" CHECK (test_checks > 0)
 Referenced by:
-    TABLE "table_b" CONSTRAINT "table_b_table_a_id_fkey" FOREIGN KEY (table_a_id) REFERENCES table_a(id)
+    TABLE "table_b" CONSTRAINT "table_b_table_a_no_fkey" FOREIGN KEY (table_a_no) REFERENCES table_a(id)


# diffs/table_b.diff
--- TABLES.diff_a.table_b
+++ TABLES.diff_b.table_b
@@ -1,9 +1,9 @@
                 Table "public.table_b"
    Column   |  Type   | Collation | Nullable | Default
 ------------+---------+-----------+----------+---------
  id         | integer |           | not null |
- table_a_id | integer |           |          |
+ table_a_no | integer |           |          |
 Indexes:
     "table_b_pkey" PRIMARY KEY, btree (id)
 Foreign-key constraints:
-    "table_b_table_a_id_fkey" FOREIGN KEY (table_a_id) REFERENCES table_a(id)
+    "table_b_table_a_no_fkey" FOREIGN KEY (table_a_no) REFERENCES table_a(id)


# diffs/view_a.diff
--- VIEWS.diff_a.view_a
+++ VIEWS.diff_b.view_a
@@ -1,6 +1,5 @@
                          View "public.view_a"
    Column    |          Type          | Collation | Nullable | Default
 -------------+------------------------+-----------+----------+---------
  id          | integer                |           |          |
- some_number | integer                |           |          |
  test_unique | character varying(100) |           |          |