add golang backend for login an d webserver

backend/dbRequest/dbRequest.go

@@ -0,0 +1,35 @@
+package dbRequest
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+var DBCreate string = `CREATE TABLE IF NOT EXISTS users (
+						id INTEGER PRIMARY KEY AUTOINCREMENT,
+						username TEXT NOT NULL,
+						password TEXT NOT NULL
+						);`
+
+var DBNewUser string = `INSERT INTO users (username, password) VALUES (?, ?)`
+var DBQueryPassword string = `SELECT password FROM users WHERE username = ?`
+var DBUserLookup string = `SELECT EXISTS(SELECT 1 FROM users WHERE username = ?)`
+var DBRemoveUser string = `DELETE FROM users WHERE username = $1`
+
+func CheckDBError(c *gin.Context, username string, err error) bool {
+	if err != nil {
+		if err.Error() == "sql: no rows in result set" {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"error": fmt.Sprintf("no user '%s' found", username),
+			})
+			return true
+		}
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error": err.Error(),
+		})
+		return true
+	}
+	return false
+}