Can get & return basic information about surveys

src/helpers/DatabaseHelper.ts

@@ -21,6 +21,7 @@ export interface QueryInformation {
 	where ?: Object,
 	customWhere ?: string,
 	customWhereArgs ?: Array<string>,
+	groupBy ?: string,
 	order ?: string,
 	limit ?: number,
 }
@@ -137,6 +138,11 @@ export class DatabaseHelper {
 				info.customWhereArgs.forEach((e) => args.push(e));
 		}
 
+		// Group by clause (if any)
+		if(info.groupBy) {
+			request += " GROUP BY " + info.groupBy + " ";
+		}
+
 		// Order (if any)
 		if(info.order)
 			request += " ORDER BY " + info.order + " ";

src/helpers/SurveyHelper.ts

@@ -0,0 +1,103 @@
+import { Survey, SurveyChoice } from "../entities/Survey";
+import { DatabaseHelper } from "./DatabaseHelper";
+
+/**
+ * Survey helper
+ * 
+ * @author Pierre HUBERT
+ */
+
+/**
+ * Survey info table
+ */
+const SURVEY_INFO_TABLE = "sondage";
+
+/**
+ * Survey choices table
+ */
+const SURVEY_CHOICES_TABLE = "sondage_choix";
+
+/**
+ * Survey responses table
+ */
+const SURVEY_RESPONSE_TABLE = "sondage_reponse";
+
+/**
+ * Survey helper
+ */
+export class SurveyHelper {
+
+	/**
+	 * Get information about the survey of a post
+	 * 
+	 * @param postID The ID of the associated post
+	 */
+	public static async GetInfo(postID: number) : Promise<Survey> {
+
+		// Get main information about the survey
+		const surveyRow = await DatabaseHelper.QueryRow({
+			table: SURVEY_INFO_TABLE,
+			where: {
+				ID_texte: postID
+			}
+		});
+
+		if(surveyRow == null)
+			throw new Error("Could not find survey for post " + postID + " !");
+		
+		const survey = this.DBToSurveyInfo(surveyRow);
+
+
+		// Get the choices of the survey
+		const choices = await DatabaseHelper.Query({
+			table: SURVEY_CHOICES_TABLE,
+			tableAlias: "c",
+			joins: [
+				{
+					table: SURVEY_RESPONSE_TABLE,
+					tableAlias: "r",
+					condition: "c.ID = r.ID_sondage_choix"
+				}
+			],
+			where: {
+				"c.ID_sondage": survey.id
+			},
+			groupBy: "c.ID",
+			fields: ["c.*", "COUNT(*) AS count_choice"]
+		});
+
+		choices.forEach((row) => survey.choices.push(this.DBToSurveyChoice(row)));
+
+		return survey;
+	}
+
+
+	/**
+	 * Turn a database entry into a survey object
+	 * 
+	 * @param row The row to transform
+	 */
+	private static DBToSurveyInfo(row: any) : Survey {
+		return new Survey({
+			id: row.ID,
+			userID: row.ID_utilisateurs,
+			postID: row.ID_texte,
+			timeCreate: new Date(row.date_creation).getTime()/1000,
+			question: row.question,
+			choices: []
+		});
+	}
+
+	/**
+	 * Turn a database entry into a survey choice
+	 * 
+	 * @param row The row to transform
+	 */
+	private static DBToSurveyChoice(row: any) : SurveyChoice {
+		return {
+			id: row.ID,
+			name: row.Choix,
+			count: row.count_choice
+		};
+	}
+}