Fix duplicate output when multiple schemas have the same named table

[oohira]

I fixed a bug that two same named tables in diffrent schemas are listed multiple times in the output Markdown file.

Version

• tbls 1.18.0
• PostgreSQL 10.10
• macOS 10.14.6

Steps to reproduce

1. Run PostgreSQL server

   $ cd $GOPATH/src/github.com/k1LoW/tbls
   $ docker-compose up postgres

2. Create a testdata initialization SQL file.

   $ vi init.sql
   CREATE SCHEMA schema1;
   CREATE SCHEMA schema2;
   -------------------------------------------------
   SET search_path TO schema1;
   CREATE TABLE users (
     id serial PRIMARY KEY,
     username varchar (50) UNIQUE NOT NULL CHECK(char_length(username) > 4),
     password varchar (50) NOT NULL,
     email varchar (355) UNIQUE NOT NULL
   );
   -------------------------------------------------
   SET search_path TO schema2;
   CREATE TABLE users (
     id serial PRIMARY KEY,
     username varchar (50) UNIQUE NOT NULL CHECK(char_length(username) > 4),
     password varchar (50) NOT NULL,
     email varchar (355) UNIQUE NOT NULL
   );

3. Execute init.sql via psql command

   $ psql -h localhost -p 55432 -U postgres testdb
   localhost postgres@testdb=# \i init.sql

4. Execute tbls

   $ tbls doc -f pg://postgres:pgpass@localhost:55432/testdb?sslmode=disable result
   $ less result/README.md

Expected behaviour (This PR)

# testdb

## Tables

| Name | Columns | Comment | Type |
| ---- | ------- | ------- | ---- |
| [schema1.users](schema1.users.md) | 4 | Users table | BASE TABLE |
| [schema2.users](schema2.users.md) | 4 | Users table | BASE TABLE |

...

Actual behaviour (Current master branch)

# testdb

## Tables

| Name | Columns | Comment | Type |
| ---- | ------- | ------- | ---- |
| [schema1.users](schema1.users.md) | 4 | Users table | BASE TABLE |
| [schema2.users](schema2.users.md) | 4 | Users table | BASE TABLE |
| [schema1.users](schema1.users.md) | 4 | Users table | BASE TABLE |
| [schema2.users](schema2.users.md) | 4 | Users table | BASE TABLE |

...

Implementation note

Current

localhost postgres@testdb=# SELECT cls.oid, relnamespace, ns.nspname, relname, tbl.table_schema FROM pg_class cls
INNER JOIN pg_namespace ns on cls.relnamespace = ns.oid
INNER JOIN (SELECT table_name, table_type, table_schema FROM information_schema.tables
    WHERE table_schema != 'pg_catalog' AND table_schema != 'information_schema') tbl
    ON cls.relname = tbl.table_name;
  oid  | relnamespace | nspname | relname | table_schema
-------+--------------+---------+---------+--------------
 16404 |        16388 | schema2 | users   | schema1    # <-- schema mismatch
 16391 |        16387 | schema1 | users   | schema1
 16404 |        16388 | schema2 | users   | schema2
 16391 |        16387 | schema1 | users   | schema2    # <-- schema mismatch
(4 rows)

Fixed

localhost postgres@testdb=# SELECT cls.oid, relnamespace, ns.nspname, relname, tbl.table_schema FROM pg_class cls
INNER JOIN pg_namespace ns on cls.relnamespace = ns.oid
INNER JOIN (SELECT table_name, table_type, table_schema FROM information_schema.tables
    WHERE table_schema != 'pg_catalog' AND table_schema != 'information_schema') tbl
    ON cls.relname = tbl.table_name AND ns.nspname = tbl.table_schema;
  oid  | relnamespace | nspname | relname | table_schema                                                     │tax error at or near ")" at character 151
-------+--------------+---------+---------+--------------                                                    │postgres_1  | 2019-08-15 06:53:09.719 UTC [118] STATEMENT: 
 16391 |        16387 | schema1 | users   | schema1                                                          │ SELECT table_name, table_type, table_schema
 16404 |        16388 | schema2 | users   | schema2                                                          │postgres_1  |   FROM information_schema.tables
(2 rows)

[codecov]

Codecov Report

Merging #134 into master will decrease coverage by 1.19%.
The diff coverage is 100%.

@@           Coverage Diff            @@
##           master    #134     +/-   ##
========================================
- Coverage   70.59%   69.4%   -1.2%     
========================================
  Files          12      12             
  Lines        2585    2585             
========================================
- Hits         1825    1794     -31     
- Misses        587     624     +37     
+ Partials      173     167      -6

Impacted Files	Coverage Δ
drivers/postgres/postgres.go	71.35% <100%> (ø)	⬆️
datasource/datasource.go	21.25% <0%> (-19.38%)	⬇️

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[k1LoW]

Hi @oohira !! THANK YOU FOR YOUR FIXXX !!

[k1LoW]

Released as v1.18.1.

[oohira]

Thank you for merging and adding an unit test case. The quick release is really welcomed. Awesome 👍