Fix bugs and document the 'where' clause

README.md

@@ -2,13 +2,13 @@
 
 ## Instant GraphQL API for Rails. Zero code.
 
-Get an instant high-performance GraphQL API for your Rails apps in seconds. Super Graph will auto learn your database structure and relationships. Built in support for Rails authentication and for JWT tokens.
+Get an high-performance GraphQL API for your Rails app in seconds. Super Graph will auto learn your database structure and relationships. Built in support for Rails authentication and JWT tokens.
 
 ## Back story and motivation
 
-I have a Rails app that gets a bit of traffic. Having planned to improve the UI using React or Vue I found that my current APIs didn't have the data I needed. I was too lazy to build new controllers. My controllers were esentially wrappers around database queries and I didn't enjoy having to figure out new REST APIs with paths, names and methods to fetch all this new data.
+I have a Rails app that gets a bit of traffic. Having planned to improve the UI using React or Vue I found that my current APIs didn't have the data I needed and I was too lazy to build new endpoints. My controllers were esentially wrappers around database queries and I didn't enjoy having to figure out new REST APIs with paths, names and methods to fetch all this new data or write the active record code needed.
 
-I always liked GraphQL and how simplifies things for web devs. On the backend however GraphQL seemed overly complex as it still required me to write a lot of the same database query code. I wanted a GraphQL server that just worked the second you deployed it without having to write a line of code.
+I always liked GraphQL and how simple it makes things for web devs. On the backend however GraphQL seemed overly complex as it still required me to write a lot of the same database query code. I wanted a GraphQL server that just worked the second you deployed it without having to write a line of code.
 
 And so after a lot of coffee and some avocado toasts we now have Super Graph, an instant GraphQL API that is high performance and quick to deploy. One service to rule all your database querying needs.
 
@@ -17,9 +17,9 @@ And so after a lot of coffee and some avocado toasts we now have Super Graph, an
 - Belongs-To, One-To-Many and Many-To-Many table relationships
 - Devise, Warden encrypted and signed session cookies
 - Redis, Memcache and Cookie session stores
-- Generates highly optimized Postgres SQL quries
+- Generates highly optimized Postgres SQL queries
 - Customize through a simple config file
-- High performance GoLang codebase
+- High performance GO codebase
 - Tiny docker image and low memory requirements
 
 ### GraphQL (GQL)
@@ -50,7 +50,6 @@ query {
 The above GQL query returns the JSON result below. It handles all
 kinds of complexity without you writing a line of code. For example there is a while greater than `gt` and a limit clause on a child field. And the `avatar` field is renamed to `picture`. The `password` field is blocked and not returned. Finally the relationship between the `users` table and the `products` table is auto discovered and used.
 
-
 #### JSON Result
 
 ```json
@@ -76,18 +75,18 @@ kinds of complexity without you writing a line of code. For example there is a w
   }
 }
 ```
-
 ## Try it out
 
-Please be patient on the first run Go has to download packages and this
-can be a little slow.
-
 ```console
 $ docker-compose run web rake db:create db:migrate db:seed
-$ docker-compose up
+$ docker-compose -f docker-compose.image.yml up
 $ open http://localhost:8080
 ```
 
+The above command will download the latest docker image for Super Graph and use it to run an example that includes a Postgres DB and a simple Rails ecommerce store app. If you want to build and run Super Graph from code then use the following command instead `docker-compose up`
+
+#### How to try with an authenticated user
+
 In development mode you can use the `X-User-ID: 4` header to set a user id so you don't have to worries about cookies etc. This can be set using the *HTTP Headers* tab at the bottom of the web UI you'll see when you visit the above link. You can also directly run quries from the commandline like shown below.
 
 #### Querying the GQL endpoint
@@ -99,11 +98,9 @@ curl 'http://localhost:8080/api/v1/graphql' \
   --data-binary '{"query":"{ products { name price users { email }}}"}'
 ```
 
-## How to GQL
+## How to GraphQL
 
-GQL is a simple query language that is fast replacing REST APIs. GQL is great
+GraphQL / GQL is a simple query syntax that is fast replacing REST APIs. GQL is great since it allows web developers to fetch the exact data that they need without depending on changes to backend code. Also if you squint hard enough it looks a little bit like JSON :)
-since it allows web developers to fetch the exact data that they need without 
-depending on changes to backend code.
 
 The below query will fetch a `users` name, email and avatar image renamed as picture. If you also need the users `id` then just add it to the query.
 
@@ -119,6 +116,39 @@ query {
 
 Super Graph support complex quries where you can add filters, ordering, offsets and limits on the query.
 
+#### Logical Operators
+
+Name | Example | Explained |
+--- | --- | --- |
+and | price : { and : { gt: 10.5, lt: 20 } | price > 10.5 AND price < 20
+or |  or : { price : { greater_than : 20 }, quantity: { gt : 0 } }  | price >= 20 OR quantity > 0
+not | not: { or : { quantity : { eq: 0 }, price : { eq: 0 } } } | NOT (quantity = 0 OR price = 0)
+
+#### Other conditions
+
+Name | Example | Explained |
+--- | --- | --- |
+eq, equals | id : { eq: 100 } | id = 100 
+neq, not_equals | id: { not_equals: 100 } | id != 100
+gt, greater_than | id: { gt: 100 } | id > 100
+lt, lesser_than | id: { gt: 100 } | id < 100
+gte, greater_or_equals | id: { gte: 100 } | id >= 100
+lte, lesser_or_equals | id: { lesser_or_equals: 100 } | id <= 100
+in | status: { in: [ "A", "B", "C" ] } | status IN ('A', 'B', 'C)
+nin, not_in | status: { in: [ "A", "B", "C" ] } | status IN ('A', 'B', 'C)
+like | name: { like "phil%" } | Names starting with 'phil'
+nlike, not_like | name: { nlike "v%m" } | Not names starting with 'v' and ending with 'm'
+ilike | name: { ilike "%wOn" } | Names ending with 'won' case-insensitive
+nilike, not_ilike | name: { nilike "%wOn" } | Not names ending with 'won' case-insensitive
+similar | name: { similar: "%(b\|d)%" } | [Similar Docs](https://www.postgresql.org/docs/9/functions-matching.html#FUNCTIONS-SIMILARTO-REGEXP)
+nsimilar, not_similar | name: { nsimilar: "%(b\|d)%" } | [Not Similar Docs](https://www.postgresql.org/docs/9/functions-matching.html#FUNCTIONS-SIMILARTO-REGEXP)
+has_key | column: { has_key: 'b' } | Does JSON column contain this key
+has_key_any | column: { has_key_any: [ a, b ] } | Does JSON column contain any of these keys
+has_key_all | column: [ a, b ] | Does JSON column contain all of this keys
+contains | column: { contains: [1, 2, 4] } | Is this array/json column a subset of value
+contained_in | column: { contains: "{'a':1, 'b':2}" } | Is this array/json column a subset of these value
+is_null | column: { is_null: true } | Is column value null or not
+
 ```javascript
 query {
   products(

psql/psql.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/dosco/super-graph/qcode"
 	"github.com/dosco/super-graph/util"
@@ -181,7 +182,7 @@ func (v *selectBlock) render(w io.Writer,
 			}
 		}
 
-		io.WriteString(w, ` ) `)
+		io.WriteString(w, `)`)
 	}
 
 	if len(v.sel.Paging.Limit) != 0 {
@@ -246,7 +247,7 @@ type joinClose struct {
 }
 
 func (v *joinClose) render(w io.Writer) error {
-	fmt.Fprintf(w, `) AS "%s_%d.join" ON ('true') `, v.sel.Table, v.sel.ID)
+	fmt.Fprintf(w, `) AS "%s_%d.join" ON ('true')`, v.sel.Table, v.sel.ID)
 	return nil
 }
 
@@ -338,15 +339,15 @@ func (v *selectBlock) renderRelationship(w io.Writer, schema *DBSchema) {
 
 	switch rel.Type {
 	case RelBelongTo:
-		fmt.Fprintf(w, ` (("%s"."%s") = ("%s_%d"."%s"))`,
+		fmt.Fprintf(w, `(("%s"."%s") = ("%s_%d"."%s"))`,
 			v.sel.Table, rel.Col1, v.parent.Table, v.parent.ID, rel.Col2)
 
 	case RelOneToMany:
-		fmt.Fprintf(w, ` (("%s"."%s") = ("%s_%d"."%s"))`,
+		fmt.Fprintf(w, `(("%s"."%s") = ("%s_%d"."%s"))`,
 			v.sel.Table, rel.Col1, v.parent.Table, v.parent.ID, rel.Col2)
 
 	case RelOneToManyThrough:
-		fmt.Fprintf(w, ` (("%s"."%s") = ("%s"."%s"))`,
+		fmt.Fprintf(w, `(("%s"."%s") = ("%s"."%s"))`,
 			v.sel.Table, rel.Col1, rel.Through, rel.Col2)
 
 	}
@@ -379,25 +380,23 @@ func (v *selectBlock) renderWhere(w io.Writer) error {
 			case qcode.OpOr:
 				io.WriteString(w, ` OR `)
 			case qcode.OpNot:
-				io.WriteString(w, ` NOT `)
+				io.WriteString(w, `NOT `)
 			default:
 				return fmt.Errorf("[Where] unexpected value encountered %v", intf)
 			}
 		case *qcode.Exp:
 			switch val.Op {
-			case qcode.OpAnd:
+			case qcode.OpAnd, qcode.OpOr:
-				st.Push(val.Children[1])
+				for i := len(val.Children) - 1; i >= 0; i-- {
-				st.Push(qcode.OpAnd)
+					st.Push(val.Children[i])
-				st.Push(val.Children[0])
+					if i > 0 {
-				continue
+						st.Push(val.Op)
-			case qcode.OpOr:
+					}
-				st.Push(val.Children[1])
+				}
-				st.Push(qcode.OpOr)
-				st.Push(val.Children[0])
 				continue
 			case qcode.OpNot:
-				st.Push(qcode.OpNot)
 				st.Push(val.Children[0])
+				st.Push(qcode.OpNot)
 				continue
 			}
 
@@ -406,6 +405,7 @@ func (v *selectBlock) renderWhere(w io.Writer) error {
 			} else {
 				fmt.Fprintf(w, `(("%s"."%s") `, v.sel.Table, val.Col)
 			}
+			valExists := true
 
 			switch val.Op {
 			case qcode.OpEquals:
@@ -437,20 +437,33 @@ func (v *selectBlock) renderWhere(w io.Writer) error {
 			case qcode.OpNotSimilar:
 				io.WriteString(w, `NOT SIMILAR TO`)
 			case qcode.OpContains:
-				io.WriteString(w, `CONTAINS`)
+				io.WriteString(w, `@>`)
 			case qcode.OpContainedIn:
-				io.WriteString(w, `CONTAINED IN`)
+				io.WriteString(w, `<@`)
 			case qcode.OpHasKey:
-				io.WriteString(w, `HAS KEY`)
+				io.WriteString(w, `?`)
+			case qcode.OpHasKeyAny:
+				io.WriteString(w, `?|`)
+			case qcode.OpHasKeyAll:
+				io.WriteString(w, `?&`)
+			case qcode.OpIsNull:
+				if strings.EqualFold(val.Val, "true") {
+					io.WriteString(w, `IS NULL`)
+				} else {
+					io.WriteString(w, `IS NOT NULL`)
+				}
+				valExists = false
 			default:
 				return fmt.Errorf("[Where] unexpected op code %d", val.Op)
 			}
 
+			if valExists {
 				if val.Type == qcode.ValList {
 					renderList(w, val)
 				} else {
 					renderVal(w, val, v.vars)
 				}
+			}
 
 			io.WriteString(w, `)`)
 

psql/psql_test.go

@@ -110,7 +110,7 @@ func compileGQLToPSQL(gql string) (string, error) {
 	return sqlStmt.String(), nil
 }
 
-func TestCompileGQLWithArgs(t *testing.T) {
+func TestCompileGQLWithComplexArgs(t *testing.T) {
 	gql := `query {
 		products(
 			# returns only 30 items
@@ -133,7 +133,87 @@ func TestCompileGQLWithArgs(t *testing.T) {
 		}
 	}`
 
-	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products" ORDER BY "products_0.ob.price" DESC), '[]') AS "products" FROM (SELECT  DISTINCT ON ("products_0.ob.price") row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "products_0"."price" AS "price") AS "sel_0")) AS "products", "products_0"."price" AS "products_0.ob.price" FROM (SELECT "products"."id", "products"."name", "products"."price" FROM "products" WHERE ((("products"."id") < (28)) AND (("products"."id") >= (20)) )  LIMIT ('30') :: integer) AS "products_0" ORDER BY "products_0.ob.price" DESC LIMIT ('30') :: integer) AS "products_0") AS "done_1337";`
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products" ORDER BY "products_0.ob.price" DESC), '[]') AS "products" FROM (SELECT  DISTINCT ON ("products_0.ob.price") row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "products_0"."price" AS "price") AS "sel_0")) AS "products", "products_0"."price" AS "products_0.ob.price" FROM (SELECT "products"."id", "products"."name", "products"."price" FROM "products" WHERE ((("products"."id") < (28)) AND (("products"."id") >= (20))) LIMIT ('30') :: integer) AS "products_0" ORDER BY "products_0.ob.price" DESC LIMIT ('30') :: integer) AS "products_0") AS "done_1337";`
+
+	resSQL, err := compileGQLToPSQL(gql)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if resSQL != sql {
+		t.Fatal(errNotExpected)
+	}
+}
+
+func TestCompileGQLWithWhereMultiOr(t *testing.T) {
+	gql := `query {
+		products(
+			where: { 
+				or: { 
+					not: { id: { is_null: true } }, 
+					price: { gt: 10 },
+					price: { lt: 20 } 
+				} }
+			) {
+			id
+			name
+			price
+		}
+	}`
+
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "products_0"."price" AS "price") AS "sel_0")) AS "products" FROM (SELECT "products"."id", "products"."name", "products"."price" FROM "products" WHERE ((("products"."price") < (20)) OR (("products"."price") > (10)) OR NOT (("products"."id") IS NULL)) LIMIT ('20') :: integer) AS "products_0" LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
+
+	resSQL, err := compileGQLToPSQL(gql)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if resSQL != sql {
+		t.Fatal(errNotExpected)
+	}
+}
+
+func TestCompileGQLWithWhereIsNull(t *testing.T) {
+	gql := `query {
+		products(
+			where: { 
+				and: { 
+					not: { id: { is_null: true } }, 
+					price: { gt: 10 } 
+				}}) {
+			id
+			name
+			price
+		}
+	}`
+
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "products_0"."price" AS "price") AS "sel_0")) AS "products" FROM (SELECT "products"."id", "products"."name", "products"."price" FROM "products" WHERE ((("products"."price") > (10)) AND NOT (("products"."id") IS NULL)) LIMIT ('20') :: integer) AS "products_0" LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
+
+	resSQL, err := compileGQLToPSQL(gql)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if resSQL != sql {
+		t.Fatal(errNotExpected)
+	}
+}
+
+func TestCompileGQLWithWhereAndList(t *testing.T) {
+	gql := `query {
+		products(
+			where: { 
+				and: [ 
+					{ not: { id: { is_null: true } } }, 
+					{ price: { gt: 10 } }, 
+				] } ) {
+			id
+			name
+			price
+		}
+	}`
+
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "products_0"."price" AS "price") AS "sel_0")) AS "products" FROM (SELECT "products"."id", "products"."name", "products"."price" FROM "products" WHERE ((("products"."price") > (10)) AND NOT (("products"."id") IS NULL)) LIMIT ('20') :: integer) AS "products_0" LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
 
 	resSQL, err := compileGQLToPSQL(gql)
 	if err != nil {
@@ -156,7 +236,7 @@ func TestCompileGQLOneToMany(t *testing.T) {
 		}
 	}`
 
-	sql := `SELECT json_object_agg('users', users) FROM (SELECT coalesce(json_agg("users"), '[]') AS "users" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "users_0"."email" AS "email", "products_1.join"."products" AS "products") AS "sel_0")) AS "users" FROM (SELECT "users"."email", "users"."id" FROM "users" WHERE ((("users"."id") = ('{{user_id}}')) )  LIMIT ('20') :: integer) AS "users_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "products_1"."name" AS "name", "products_1"."price" AS "price") AS "sel_1")) AS "products" FROM (SELECT "products"."name", "products"."price" FROM "products" WHERE ( (("products"."user_id") = ("users_0"."id")) )  LIMIT ('20') :: integer) AS "products_1" LIMIT ('20') :: integer) AS "products_1") AS "products_1.join" ON ('true')  LIMIT ('20') :: integer) AS "users_0") AS "done_1337";`
+	sql := `SELECT json_object_agg('users', users) FROM (SELECT coalesce(json_agg("users"), '[]') AS "users" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "users_0"."email" AS "email", "products_1.join"."products" AS "products") AS "sel_0")) AS "users" FROM (SELECT "users"."email", "users"."id" FROM "users" WHERE ((("users"."id") = ('{{user_id}}'))) LIMIT ('20') :: integer) AS "users_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "products_1"."name" AS "name", "products_1"."price" AS "price") AS "sel_1")) AS "products" FROM (SELECT "products"."name", "products"."price" FROM "products" WHERE ((("products"."user_id") = ("users_0"."id"))) LIMIT ('20') :: integer) AS "products_1" LIMIT ('20') :: integer) AS "products_1") AS "products_1.join" ON ('true') LIMIT ('20') :: integer) AS "users_0") AS "done_1337";`
 
 	resSQL, err := compileGQLToPSQL(gql)
 	if err != nil {
@@ -179,7 +259,7 @@ func TestCompileGQLBelongTo(t *testing.T) {
 		}
 	}`
 
-	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."name" AS "name", "products_0"."price" AS "price", "users_1.join"."users" AS "users") AS "sel_0")) AS "products" FROM (SELECT "products"."name", "products"."price", "products"."user_id" FROM "products" LIMIT ('20') :: integer) AS "products_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("users"), '[]') AS "users" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "users_1"."email" AS "email") AS "sel_1")) AS "users" FROM (SELECT "users"."email" FROM "users" WHERE ( (("users"."id") = ("products_0"."user_id")) )  LIMIT ('20') :: integer) AS "users_1" LIMIT ('20') :: integer) AS "users_1") AS "users_1.join" ON ('true')  LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."name" AS "name", "products_0"."price" AS "price", "users_1.join"."users" AS "users") AS "sel_0")) AS "products" FROM (SELECT "products"."name", "products"."price", "products"."user_id" FROM "products" LIMIT ('20') :: integer) AS "products_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("users"), '[]') AS "users" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "users_1"."email" AS "email") AS "sel_1")) AS "users" FROM (SELECT "users"."email" FROM "users" WHERE ((("users"."id") = ("products_0"."user_id"))) LIMIT ('20') :: integer) AS "users_1" LIMIT ('20') :: integer) AS "users_1") AS "users_1.join" ON ('true') LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
 
 	resSQL, err := compileGQLToPSQL(gql)
 	if err != nil {
@@ -202,7 +282,7 @@ func TestCompileGQLManyToMany(t *testing.T) {
 		}
 	}`
 
-	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."name" AS "name", "customers_1.join"."customers" AS "customers") AS "sel_0")) AS "products" FROM (SELECT "products"."name", "products"."id" FROM "products" LIMIT ('20') :: integer) AS "products_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("customers"), '[]') AS "customers" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "customers_1"."email" AS "email", "customers_1"."full_name" AS "full_name") AS "sel_1")) AS "customers" FROM (SELECT "customers"."email", "customers"."full_name" FROM "customers" LEFT OUTER JOIN "purchases" ON (("purchases"."product_id") = ("products_0"."id")) WHERE ( (("customers"."id") = ("purchases"."customer_id")) )  LIMIT ('20') :: integer) AS "customers_1" LIMIT ('20') :: integer) AS "customers_1") AS "customers_1.join" ON ('true')  LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
+	sql := `SELECT json_object_agg('products', products) FROM (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "products_0"."name" AS "name", "customers_1.join"."customers" AS "customers") AS "sel_0")) AS "products" FROM (SELECT "products"."name", "products"."id" FROM "products" LIMIT ('20') :: integer) AS "products_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("customers"), '[]') AS "customers" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "customers_1"."email" AS "email", "customers_1"."full_name" AS "full_name") AS "sel_1")) AS "customers" FROM (SELECT "customers"."email", "customers"."full_name" FROM "customers" LEFT OUTER JOIN "purchases" ON (("purchases"."product_id") = ("products_0"."id")) WHERE ((("customers"."id") = ("purchases"."customer_id"))) LIMIT ('20') :: integer) AS "customers_1" LIMIT ('20') :: integer) AS "customers_1") AS "customers_1.join" ON ('true') LIMIT ('20') :: integer) AS "products_0") AS "done_1337";`
 
 	resSQL, err := compileGQLToPSQL(gql)
 	if err != nil {
@@ -225,7 +305,7 @@ func TestCompileGQLManyToManyReverse(t *testing.T) {
 		}
 	}`
 
-	sql := `SELECT json_object_agg('customers', customers) FROM (SELECT coalesce(json_agg("customers"), '[]') AS "customers" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "customers_0"."email" AS "email", "customers_0"."full_name" AS "full_name", "products_1.join"."products" AS "products") AS "sel_0")) AS "customers" FROM (SELECT "customers"."email", "customers"."full_name", "customers"."id" FROM "customers" LIMIT ('20') :: integer) AS "customers_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "products_1"."name" AS "name") AS "sel_1")) AS "products" FROM (SELECT "products"."name" FROM "products" LEFT OUTER JOIN "purchases" ON (("purchases"."customer_id") = ("customers_0"."id")) WHERE ( (("products"."id") = ("purchases"."product_id")) )  LIMIT ('20') :: integer) AS "products_1" LIMIT ('20') :: integer) AS "products_1") AS "products_1.join" ON ('true')  LIMIT ('20') :: integer) AS "customers_0") AS "done_1337";`
+	sql := `SELECT json_object_agg('customers', customers) FROM (SELECT coalesce(json_agg("customers"), '[]') AS "customers" FROM (SELECT row_to_json((SELECT "sel_0" FROM (SELECT "customers_0"."email" AS "email", "customers_0"."full_name" AS "full_name", "products_1.join"."products" AS "products") AS "sel_0")) AS "customers" FROM (SELECT "customers"."email", "customers"."full_name", "customers"."id" FROM "customers" LIMIT ('20') :: integer) AS "customers_0" LEFT OUTER JOIN LATERAL (SELECT coalesce(json_agg("products"), '[]') AS "products" FROM (SELECT row_to_json((SELECT "sel_1" FROM (SELECT "products_1"."name" AS "name") AS "sel_1")) AS "products" FROM (SELECT "products"."name" FROM "products" LEFT OUTER JOIN "purchases" ON (("purchases"."customer_id") = ("customers_0"."id")) WHERE ((("products"."id") = ("purchases"."product_id"))) LIMIT ('20') :: integer) AS "products_1" LIMIT ('20') :: integer) AS "products_1") AS "products_1.join" ON ('true') LIMIT ('20') :: integer) AS "customers_0") AS "done_1337";`
 
 	resSQL, err := compileGQLToPSQL(gql)
 	if err != nil {

qcode/parse.go

@@ -332,14 +332,11 @@ func (p *Parser) parseArgs() ([]*Arg, error) {
 	return args, nil
 }
 
-func (p *Parser) parseList(parent *Node) ([]*Node, error) {
+func (p *Parser) parseList() (*Node, error) {
+	parent := &Node{}
 	var nodes []*Node
 	var ty parserType
 
-	if parent == nil {
-		return nil, errors.New("list needs a parent")
-	}
-
 	for {
 		if p.peek(itemListClose) {
 			p.ignore()
@@ -356,6 +353,7 @@ func (p *Parser) parseList(parent *Node) ([]*Node, error) {
 				return nil, errors.New("All values in a list must be of the same type")
 			}
 		}
+		node.Parent = parent
 		nodes = append(nodes, node)
 	}
 	if len(nodes) == 0 {
@@ -365,16 +363,13 @@ func (p *Parser) parseList(parent *Node) ([]*Node, error) {
 	parent.Type = nodeList
 	parent.Children = nodes
 
-	return nodes, nil
+	return parent, nil
 }
 
-func (p *Parser) parseObj(parent *Node) ([]*Node, error) {
+func (p *Parser) parseObj() (*Node, error) {
+	parent := &Node{}
 	var nodes []*Node
 
-	if parent == nil {
-		return nil, errors.New("object needs a parent")
-	}
-
 	for {
 		if p.peek(itemObjClose) {
 			p.ignore()
@@ -403,33 +398,22 @@ func (p *Parser) parseObj(parent *Node) ([]*Node, error) {
 	parent.Type = nodeObj
 	parent.Children = nodes
 
-	return nodes, nil
+	return parent, nil
 }
 
 func (p *Parser) parseValue() (*Node, error) {
-	node := &Node{}
-
-	var done bool
-	var err error
-
 	if p.peek(itemListOpen) {
 		p.ignore()
-		node.Children, err = p.parseList(node)
+		return p.parseList()
-		done = true
 	}
 
 	if p.peek(itemObjOpen) {
 		p.ignore()
-		node.Children, err = p.parseObj(node)
+		return p.parseObj()
-		done = true
 	}
 
-	if err != nil {
-		return nil, err
-	}
-
-	if !done {
 	item := p.next()
+	node := &Node{}
 
 	switch item.typ {
 	case itemIntVal:
@@ -448,7 +432,6 @@ func (p *Parser) parseValue() (*Node, error) {
 		return nil, fmt.Errorf("expecting a number, string, object, list or variable as an argument value (not %s)", p.next().val)
 	}
 	node.Val = item.val
-	}
 
 	return node, nil
 }

qcode/qcode.go

@@ -86,6 +86,60 @@ const (
 	OpIsNull
 )
 
+func (t ExpOp) String() string {
+	var v string
+
+	switch t {
+	case OpAnd:
+		v = "op-and"
+	case OpOr:
+		v = "op-or"
+	case OpNot:
+		v = "op-not"
+	case OpEquals:
+		v = "op-equals"
+	case OpNotEquals:
+		v = "op-not-equals"
+	case OpGreaterOrEquals:
+		v = "op-greater-or-equals"
+	case OpLesserOrEquals:
+		v = "op-lesser-or-equals"
+	case OpGreaterThan:
+		v = "op-greater-than"
+	case OpLesserThan:
+		v = "op-lesser-than"
+	case OpIn:
+		v = "op-in"
+	case OpNotIn:
+		v = "op-not-in"
+	case OpLike:
+		v = "op-like"
+	case OpNotLike:
+		v = "op-not-like"
+	case OpILike:
+		v = "op-i-like"
+	case OpNotILike:
+		v = "op-not-i-like"
+	case OpSimilar:
+		v = "op-similar"
+	case OpNotSimilar:
+		v = "op-not-similar"
+	case OpContains:
+		v = "op-contains"
+	case OpContainedIn:
+		v = "op-contained-in"
+	case OpHasKey:
+		v = "op-has-key"
+	case OpHasKeyAny:
+		v = "op-has-key-any"
+	case OpHasKeyAll:
+		v = "op-has-key-all"
+	case OpIsNull:
+		v = "op-is-null"
+	}
+	return fmt.Sprintf("<%s>", v)
+}
+
 type ValType int
 
 const (
@@ -95,6 +149,7 @@ const (
 	ValBool
 	ValList
 	ValVar
+	ValNone
 )
 
 type AggregrateOp int
@@ -320,112 +375,20 @@ func (com *Compiler) compileArgNode(val *Node) (*Exp, error) {
 		if !ok || eT == nil {
 			return nil, fmt.Errorf("[Where] unexpected value poped out %v", intf)
 		}
-		node := eT.node
 
-		if com.bl != nil && com.bl.MatchString(node.Name) {
+		if len(eT.node.Name) != 0 &&
+			com.bl != nil && com.bl.MatchString(eT.node.Name) {
 			continue
 		}
 
-		ex := &Exp{}
+		ex, err := newExp(st, eT)
 
-		name := strings.ToLower(node.Name)
+		if err != nil {
-		if name[0] == '_' {
+			return nil, err
-			name = name[1:]
 		}
 
-		switch name {
+		if ex == nil {
-		case "and":
+			continue
-			ex.Op = OpAnd
-			pushChildren(st, ex, node)
-		case "or":
-			ex.Op = OpOr
-			pushChildren(st, ex, node)
-		case "not":
-			ex.Op = OpNot
-			pushChildren(st, ex, node)
-		case "eq", "equals":
-			ex.Op = OpEquals
-			ex.Val = node.Val
-		case "neq", "not_equals":
-			ex.Op = OpNotEquals
-			ex.Val = node.Val
-		case "gt", "greater_than":
-			ex.Op = OpGreaterThan
-			ex.Val = node.Val
-		case "lt", "lesser_than":
-			ex.Op = OpLesserThan
-			ex.Val = node.Val
-		case "gte", "greater_or_equals":
-			ex.Op = OpGreaterOrEquals
-			ex.Val = node.Val
-		case "lte", "lesser_or_equals":
-			ex.Op = OpLesserOrEquals
-			ex.Val = node.Val
-		case "in":
-			ex.Op = OpIn
-			setListVal(ex, node)
-		case "nin", "not_in":
-			ex.Op = OpNotIn
-			setListVal(ex, node)
-		case "like":
-			ex.Op = OpLike
-			ex.Val = node.Val
-		case "nlike", "not_like":
-			ex.Op = OpNotLike
-			ex.Val = node.Val
-		case "ilike":
-			ex.Op = OpILike
-			ex.Val = node.Val
-		case "nilike", "not_ilike":
-			ex.Op = OpILike
-			ex.Val = node.Val
-		case "similar":
-			ex.Op = OpSimilar
-			ex.Val = node.Val
-		case "nsimilar", "not_similar":
-			ex.Op = OpNotSimilar
-			ex.Val = node.Val
-		case "contains":
-			ex.Op = OpContains
-			ex.Val = node.Val
-		case "contained_in":
-			ex.Op = OpContainedIn
-			ex.Val = node.Val
-		case "has_key":
-			ex.Op = OpHasKey
-			ex.Val = node.Val
-		case "has_key_any":
-			ex.Op = OpHasKeyAny
-			ex.Val = node.Val
-		case "has_key_all":
-			ex.Op = OpHasKeyAll
-			ex.Val = node.Val
-		case "is_null":
-			ex.Op = OpIsNull
-			ex.Val = node.Val
-		default:
-			pushChildren(st, eT.parent, node)
-			continue // skip node
-		}
-
-		if ex.Op != OpAnd && ex.Op != OpOr && ex.Op != OpNot {
-			switch node.Type {
-			case nodeStr:
-				ex.Type = ValStr
-			case nodeInt:
-				ex.Type = ValInt
-			case nodeBool:
-				ex.Type = ValBool
-			case nodeFloat:
-				ex.Type = ValFloat
-			case nodeList:
-				ex.Type = ValList
-			case nodeVar:
-				ex.Type = ValVar
-			default:
-				return nil, fmt.Errorf("[Where] valid values include string, int, float, boolean and list: %s", node.Type)
-			}
-			setWhereColName(ex, node)
 		}
 
 		if eT.parent == nil {
@@ -563,6 +526,118 @@ func compileSub() (*Query, error) {
 	return nil, nil
 }
 
+func newExp(st *util.Stack, eT *expT) (*Exp, error) {
+	ex := &Exp{}
+	node := eT.node
+
+	if len(node.Name) == 0 {
+		pushChildren(st, eT.parent, node)
+		return nil, nil
+	}
+
+	name := strings.ToLower(node.Name)
+	if name[0] == '_' {
+		name = name[1:]
+	}
+
+	switch name {
+	case "and":
+		ex.Op = OpAnd
+		pushChildren(st, ex, node)
+	case "or":
+		ex.Op = OpOr
+		pushChildren(st, ex, node)
+	case "not":
+		ex.Op = OpNot
+		st.Push(&expT{ex, node.Children[0]})
+	case "eq", "equals":
+		ex.Op = OpEquals
+		ex.Val = node.Val
+	case "neq", "not_equals":
+		ex.Op = OpNotEquals
+		ex.Val = node.Val
+	case "gt", "greater_than":
+		ex.Op = OpGreaterThan
+		ex.Val = node.Val
+	case "lt", "lesser_than":
+		ex.Op = OpLesserThan
+		ex.Val = node.Val
+	case "gte", "greater_or_equals":
+		ex.Op = OpGreaterOrEquals
+		ex.Val = node.Val
+	case "lte", "lesser_or_equals":
+		ex.Op = OpLesserOrEquals
+		ex.Val = node.Val
+	case "in":
+		ex.Op = OpIn
+		setListVal(ex, node)
+	case "nin", "not_in":
+		ex.Op = OpNotIn
+		setListVal(ex, node)
+	case "like":
+		ex.Op = OpLike
+		ex.Val = node.Val
+	case "nlike", "not_like":
+		ex.Op = OpNotLike
+		ex.Val = node.Val
+	case "ilike":
+		ex.Op = OpILike
+		ex.Val = node.Val
+	case "nilike", "not_ilike":
+		ex.Op = OpILike
+		ex.Val = node.Val
+	case "similar":
+		ex.Op = OpSimilar
+		ex.Val = node.Val
+	case "nsimilar", "not_similar":
+		ex.Op = OpNotSimilar
+		ex.Val = node.Val
+	case "contains":
+		ex.Op = OpContains
+		ex.Val = node.Val
+	case "contained_in":
+		ex.Op = OpContainedIn
+		ex.Val = node.Val
+	case "has_key":
+		ex.Op = OpHasKey
+		ex.Val = node.Val
+	case "has_key_any":
+		ex.Op = OpHasKeyAny
+		ex.Val = node.Val
+	case "has_key_all":
+		ex.Op = OpHasKeyAll
+		ex.Val = node.Val
+	case "is_null":
+		ex.Op = OpIsNull
+		ex.Val = node.Val
+	default:
+		pushChildren(st, eT.parent, node)
+		return nil, nil // skip node
+	}
+
+	if ex.Op != OpAnd && ex.Op != OpOr && ex.Op != OpNot {
+		switch node.Type {
+		case nodeStr:
+			ex.Type = ValStr
+		case nodeInt:
+			ex.Type = ValInt
+		case nodeBool:
+			ex.Type = ValBool
+		case nodeFloat:
+			ex.Type = ValFloat
+		case nodeList:
+			ex.Type = ValList
+		case nodeVar:
+			ex.Type = ValVar
+		default:
+			return nil, fmt.Errorf("[Where] valid values include string, int, float, boolean and list: %s", node.Type)
+		}
+		setWhereColName(ex, node)
+	}
+
+	return ex, nil
+}
+
 func setListVal(ex *Exp, node *Node) {
 	if len(node.Children) != 0 {
 		switch node.Children[0].Type {