Add examples/pgxsupport

Makefile

@@ -68,3 +68,7 @@ $(GOBIN)/mockgen:
 # Running examples:
 exampleservice: mock
 	$(GOPATH)/bin/richgo test ./examples/example_service/...
+
+PG_URL=
+pgxsupport:
+	go run ./examples/pgxsupport/.

examples/pgxsupport/main.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/vingarcia/ksql"
+	"github.com/vingarcia/ksql/adapters/kpgx"
+)
+
+type User struct {
+	ID   int    `ksql:"id"`
+	Name string `ksql:"name"`
+}
+
+type TeamMember struct {
+	TeamID int `ksql:"team_id"`
+	UserID int `ksql:"user_id"`
+}
+
+var UsersTable = ksql.NewTable("users", "id")
+
+var TeamMembersTable = ksql.NewTable("team_members", "user_id", "team_id")
+
+func main() {
+	ctx := context.Background()
+
+	db, err := kpgx.New(ctx, os.Getenv("PG_URL"), ksql.Config{})
+	if err != nil {
+		panic(err.Error())
+	}
+	defer db.Close()
+
+	db.Exec(ctx, `DROP TABLE team_members`)
+	_, err = db.Exec(ctx, `CREATE TABLE IF NOT EXISTS team_members (
+	  user_id INTEGER,
+	  team_id INTEGER,
+		PRIMARY KEY (user_id, team_id)
+	)`)
+	if err != nil {
+		panic(err.Error())
+	}
+
+	db.Exec(ctx, `DROP TABLE users`)
+	_, err = db.Exec(ctx, `CREATE TABLE IF NOT EXISTS users (
+	  id serial PRIMARY KEY,
+		name TEXT
+	)`)
+	if err != nil {
+		panic(err.Error())
+	}
+
+	u := User{
+		Name: "ExampleUser1",
+	}
+	err = db.Insert(ctx, UsersTable, &u)
+	if err != nil {
+		panic(err.Error())
+	}
+
+	err = db.Insert(ctx, TeamMembersTable, &TeamMember{
+		UserID: u.ID,
+		TeamID: 42,
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+
+	err = db.Insert(ctx, TeamMembersTable, &TeamMember{
+		UserID: u.ID,
+		TeamID: 43,
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+
+	err = db.Insert(ctx, TeamMembersTable, &TeamMember{
+		UserID: u.ID,
+		TeamID: 44,
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+
+	userID := u.ID
+
+	// The example below illustrates how it is possible to use pgx
+	// special support to slices Inside a query:
+
+	// Find user iff user belongs to either team on the input list:
+	var user User
+	err = db.QueryOne(ctx, &user,
+		`SELECT u.*
+		FROM users AS u
+		JOIN team_members AS tm
+			ON u.id = tm.user_id
+		WHERE u.id = $1
+			AND tm.team_id = ANY($2)`,
+		userID,
+		[]int{1, 2, 42},
+	)
+	if err == ksql.ErrRecordNotFound {
+		fmt.Println("Input user does not exist or does not belong to any of the provided teams")
+		return
+	} else if err != nil {
+		log.Fatalf("unexpected error: %s", err)
+	}
+
+	fmt.Printf("Found user: %+v\n", user)
+}