Merge pull request #34 from varnion/master

Support for EXCEPT and EXCEPT ALL clauses

Author: ukriish

README.md

@@ -23,24 +23,26 @@ Currently honeysql-postgres supports the following postgres specific clauses:
   - rename column
 - insert-into-as
 - pattern matching (ILIKE and NOT ILIKE)
+- except (and except-all)
 
 ## Index
 
-- [Usage](https://github.com/nilenso/honeysql-postgres#usage)
-  - [Leiningen](https://github.com/nilenso/honeysql-postgres#leiningen)
-  - [Maven](https://github.com/nilenso/honeysql-postgres#maven)
-  - [repl](https://github.com/nilenso/honeysql-postgres#repl)
-  - [Breaking Change](https://github.com/nilenso/honeysql-postgres#breaking-change)
-  - [upsert](https://github.com/nilenso/honeysql-postgres#upsert)
-  - [insert into with alias](https://github.com/nilenso/honeysql-postgres#insert-into-with-alias)
-  - [over](https://github.com/nilenso/honeysql-postgres#over)
-  - [create view](https://github.com/nilenso/honeysql-postgres#create-view)
-  - [create table](https://github.com/nilenso/honeysql-postgres#create-table)
-  - [drop table](https://github.com/nilenso/honeysql-postgres#drop-table)
-  - [alter table](https://github.com/nilenso/honeysql-postgres#alter-table)
-  - [pattern matching](https://github.com/nilenso/honeysql-postgres#pattern-matching)
-  - [SQL functions](https://github.com/nilenso/honeysql-postgres#sql-functions)
-- [License](https://github.com/nilenso/honeysql-postgres#license)
+- [Usage](#usage)
+  - [Leiningen](#leiningen)
+  - [Maven](#maven)
+  - [repl](#repl)
+  - [Breaking Change](#breaking-change)
+  - [upsert](#upsert)
+  - [insert into with alias](#insert-into-with-alias)
+  - [over](#over)
+  - [create view](#create-view)
+  - [create table](#create-table)
+  - [drop table](#drop-table)
+  - [alter table](#alter-table)
+  - [pattern matching](#pattern-matching)
+  - [except](#except)
+  - [SQL functions](#sql-functions)
+- [License](#license)
 
 ## Usage
 
@@ -181,6 +183,17 @@ The `ilike` and `not-ilike` operators can be used to query data using a pattern
     sql/format)
 => ["SELECT * FROM products WHERE name NOT ILIKE ?" "%name%"]
 ```
+### except
+
+```clj
+
+(sql/format
+  {:except
+    [{:select [:ip]}
+     {:select [:ip] :from [:ip_location]}]})
+=> ["SELECT ip EXCEPT SELECT ip FROM ip_location"]
+```
+`except-all` works the same way as `except`.
 
 ### SQL functions
 The following are the SQL functions added in `honeysql-postgres`

project.clj

@@ -1,4 +1,4 @@
-(defproject nilenso/honeysql-postgres "0.2.5"
+(defproject nilenso/honeysql-postgres "0.2.6"
   :description "PostgreSQL extension for honeysql"
   :url "https://github.com/nilenso/honeysql-postgres"
   :license {:name "Eclipse Public License"

src/honeysql_postgres/format.cljc

@@ -1,7 +1,8 @@
 (ns ^{:doc "Extension of the honeysql format functions specifically for postgreSQL"}
     honeysql-postgres.format
   (:require [honeysql.format :as sqlf :refer [fn-handler format-clause]] ;; multi-methods
-            [honeysql-postgres.util :as util]))
+            [honeysql-postgres.util :as util]
+            [clojure.string :as string]))
 
 (def ^:private custom-additions
   {:create-table 10
@@ -26,6 +27,8 @@
   "Determines the order that clauses will be placed within generated SQL"
   (merge {:with 30
           :with-recursive 40
+          :except 45
+          :except-all 45
           :select 50
           :insert-into 60
           :update 70
@@ -208,4 +211,12 @@
 (defmethod format-clause :insert-into-as [[_ [table-name table-alias]] _]
   (str  "INSERT INTO " (sqlf/to-sql table-name) " AS " (sqlf/to-sql table-alias)))
 
+(defmethod format-clause :except [[_ maps] _]
+  (binding [sqlf/*subquery?* false]
+    (string/join " EXCEPT " (map sqlf/to-sql maps))))
+
+(defmethod format-clause :except-all [[_ maps] _]
+  (binding [sqlf/*subquery?* false]
+    (string/join " EXCEPT ALL " (map sqlf/to-sql maps))))
+
 (override-default-clause-priority)

test/honeysql_postgres/postgres_test.cljc

@@ -219,3 +219,38 @@
               (from :products)
               (where [:not-ilike :name "%name%"])
               sql/format)))))
+
+(deftest values-except-select
+  (testing "select which values are not not present in a table"
+    (is (= ["VALUES (?), (?), (?) EXCEPT SELECT id FROM images" 4 5 6]
+           (sql/format
+                  {:except
+                   [{:values [[4] [5] [6]]}
+                    {:select [:id] :from [:images]}]})))))
+
+
+(deftest select-except-select
+  (testing "select which rows are not present in another table"
+    (is (= ["SELECT ip EXCEPT SELECT ip FROM ip_location"]
+           (sql/format
+            {:except
+             [{:select [:ip]}
+              {:select [:ip] :from [:ip_location]}]})))))
+
+
+(deftest values-except-all-select
+  (testing "select which values are not not present in a table"
+    (is (= ["VALUES (?), (?), (?) EXCEPT ALL SELECT id FROM images" 4 5 6]
+           (sql/format
+            {:except-all
+             [{:values [[4] [5] [6]]}
+              {:select [:id] :from [:images]}]})))))
+
+
+(deftest select-except-all-select
+  (testing "select which rows are not present in another table"
+    (is (= ["SELECT ip EXCEPT ALL SELECT ip FROM ip_location"]
+           (sql/format
+            {:except-all
+             [{:select [:ip]}
+              {:select [:ip] :from [:ip_location]}]})))))