Adds insert plan function

store/postgres.go

@@ -1,7 +1,6 @@
 package store
 
 import (
-	"fmt"
 	"gitea.deepak.science/deepak/gogmagog/models"
 	"gitea.deepak.science/deepak/gogmagog/util"
 	"github.com/jmoiron/sqlx"
@@ -55,5 +54,17 @@ func (store *postgresStore) SelectPlanByID(id int) (*models.Plan, error) {
 }
 
 func (store *postgresStore) InsertPlan(plan *models.Plan) (int, error) {
-	return 0, fmt.Errorf("Unimplemented method")
+	queryString := store.db.Rebind("INSERT INTO plans (plan_date) VALUES (?) RETURNING plan_id")
+	tx := store.db.MustBegin()
+	var id int
+	err := tx.Get(&id, queryString, plan.PlanDate)
+	if err != nil {
+		tx.Rollback()
+		return -1, err
+	}
+	err = tx.Commit()
+	if err != nil {
+		return -1, err
+	}
+	return id, nil
 }