Database manager added

dbmanager.cpp

@@ -0,0 +1,125 @@
+#include <dbmanager.h>
+#include <QSqlQuery>
+#include <QSqlError>
+#include <QSqlRecord>
+#include <QDebug>
+
+DbManager::DbManager(const QString &path)
+{
+    m_db = QSqlDatabase::addDatabase("QSQLITE");
+    m_db.setDatabaseName(path);
+
+    if (!m_db.open())
+    {
+        qDebug() << "Error: connection with database fail";
+    }
+    else
+    {
+        qDebug() << "Database: connection ok";
+    }
+}
+
+bool DbManager::addPerson(const QString& name)
+{
+    bool success = false;
+
+    if (!name.isEmpty())
+    {
+        QSqlQuery queryAdd;
+        queryAdd.prepare("INSERT INTO people (name) VALUES (:name)");
+        queryAdd.bindValue(":name", name);
+
+        if(queryAdd.exec())
+        {
+            success = true;
+        }
+        else
+        {
+            qDebug() << "add person failed: " << queryAdd.lastError();
+        }
+    }
+    else
+    {
+        qDebug() << "add person failed: name cannot be empty";
+    }
+
+    return success;
+}
+
+bool DbManager::removePerson(const QString& name)
+{
+    bool success = false;
+
+    if (personExists(name))
+    {
+        QSqlQuery queryDelete;
+        queryDelete.prepare("DELETE FROM people WHERE name = (:name)");
+        queryDelete.bindValue(":name", name);
+        success = queryDelete.exec();
+
+        if(!success)
+        {
+            qDebug() << "remove person failed: " << queryDelete.lastError();
+        }
+    }
+    else
+    {
+        qDebug() << "remove person failed: person doesnt exist";
+    }
+
+    return success;
+}
+
+void DbManager::printAllPersons() const
+{
+    qDebug() << "Persons in db:";
+    QSqlQuery query("SELECT * FROM people");
+    int idName = query.record().indexOf("name");
+    while (query.next())
+    {
+        QString name = query.value(idName).toString();
+        qDebug() << "===" << name;
+    }
+}
+
+bool DbManager::personExists(const QString& name) const
+{
+    bool exists = false;
+
+    QSqlQuery checkQuery;
+    checkQuery.prepare("SELECT name FROM people WHERE name = (:name)");
+    checkQuery.bindValue(":name", name);
+
+    if (checkQuery.exec())
+    {
+        if (checkQuery.next())
+        {
+            exists = true;
+        }
+    }
+    else
+    {
+        qDebug() << "person exists failed: " << checkQuery.lastError();
+    }
+
+    return exists;
+}
+
+bool DbManager::removeAllPersons()
+{
+    bool success = false;
+
+    QSqlQuery removeQuery;
+    removeQuery.prepare("DELETE FROM people");
+
+    if (removeQuery.exec())
+    {
+        success = true;
+    }
+    else
+    {
+        qDebug() << "remove all persons failed: " << removeQuery.lastError();
+    }
+
+    return success;
+}

dbmanager.h

@@ -0,0 +1,20 @@
+#ifndef DBMANAGER_H
+#define DBMANAGER_H
+
+#include <QSqlDatabase>
+
+class DbManager
+{
+public:
+    DbManager(const QString& path);
+    bool addPerson(const QString& name);
+    bool removePerson(const QString& name);
+    bool personExists(const QString& name) const;
+    void printAllPersons() const;
+    bool removeAllPersons();
+
+private:
+    QSqlDatabase m_db;
+};
+
+#endif // DBMANAGER_H

main.cpp

@@ -0,0 +1,20 @@
+#include <QCoreApplication>
+#include <dbmanager.h>
+
+// Set valid db path before first run
+static const QString path = "/path/people.db";
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication a(argc, argv);
+
+    DbManager db(path);
+    db.addPerson("A");
+    db.addPerson("B");
+    db.addPerson("C");
+    db.printAllPersons();
+    db.removePerson("C");
+    db.printAllPersons();
+    db.removeAllPersons();
+    return a.exec();
+}

sqlite_qt.pro

@@ -0,0 +1,22 @@
+#-------------------------------------------------
+#
+# Project created by QtCreator 2015-08-27T18:41:32
+#
+#-------------------------------------------------
+
+QT       += core sql
+
+QT       -= gui
+
+TARGET = sqlite_qt
+CONFIG   += console
+CONFIG   -= app_bundle
+
+TEMPLATE = app
+
+
+SOURCES += main.cpp \
+    dbmanager.cpp
+
+HEADERS += \
+    dbmanager.h