Add writer interface

main.go

@@ -50,7 +50,10 @@ func main() {
 		fmt.Print(err)
 		os.Exit(1)
 	}
-	err = query.QueryResult(conset)
+
+	writer := &SimpleWriter{}
+
+	err = query.QueryResult(conset, writer)
 	if err != nil {
 		fmt.Print(err)
 		os.Exit(1)

query.go

@@ -39,7 +39,7 @@ type ConnectionSettings struct {
 }
 
 // QueryResult returns rows of data from DB
-func (q *Query) QueryResult(conset *ConnectionSettings) (err error) {
+func (q *Query) QueryResult(conset *ConnectionSettings, writer DataWriter) (err error) {
 	db, err := getDb(conset)
 	if err != nil {
 		log.Fatal(err)
@@ -60,25 +60,25 @@ func (q *Query) QueryResult(conset *ConnectionSettings) (err error) {
 		if err != nil {
 			return err
 		}
-		DumpResults(resultsMaps)
+		writer.Write(resultsMaps)
 	}
 	return
 }
 
-func dbSelect(db *sqlx.DB, query string, args ...interface{}) (resultsMaps []map[string]interface{}, err error) {
+func dbSelect(db *sqlx.DB, query string, args ...interface{}) (resultsMaps []*map[string]interface{}, err error) {
 	rows, err := db.Queryx(query, args...)
 	if err != nil {
 		return
 	}
 
-	resultsMaps = make([]map[string]interface{}, 0)
+	resultsMaps = make([]*map[string]interface{}, 0)
 	for rows.Next() {
 		results := make(map[string]interface{})
 		err = rows.MapScan(results)
 		if err != nil {
 			return
 		}
-		resultsMaps = append(resultsMaps, results)
+		resultsMaps = append(resultsMaps, &results)
 	}
 	return resultsMaps, nil
 }

writer.go

@@ -4,9 +4,16 @@ import (
 	"fmt"
 )
 
-func DumpResults(results []map[string]interface{}) {
+type DataWriter interface {
+	Write(results []*map[string]interface{}) (err error)
+}
+
+type SimpleWriter struct {
+}
+
+func (w *SimpleWriter) Write(results []*map[string]interface{}) (err error) {
 	for _, row := range results {
-		for field, v := range row {
+		for field, v := range *row {
 			value := ""
 			switch typedValue := v.(type) {
 			case int:
@@ -32,4 +39,5 @@ func DumpResults(results []map[string]interface{}) {
 		}
 		fmt.Println("")
 	}
+	return nil
 }