改进部分代码

dbpage/dbpage.cpp

@@ -144,8 +144,6 @@ DbPage *DbPage::Instance()
 DbPage::DbPage(QObject *parent) : QObject(parent)
 {
     startIndex = 0;
-    tempSql = "";
-    sql = "";
     queryModel = new SqlQueryModel;
 
     pageCurrent = 1;
@@ -260,6 +258,24 @@ void DbPage::bindData(const QString &sql)
     emit receivePage(pageCurrent, pageCount, resultCount, resultCurrent);
 }
 
+QString DbPage::getPageSql()
+{
+    //组织分页SQL语句,不同的数据库分页语句不一样
+    QString sql = QString("select %1 from %2 %3 order by %4").arg(selectColumn).arg(tableName).arg(whereSql).arg(orderSql);
+    if (dbType == DbType_PostgreSQL || dbType == DbType_KingBase) {
+        sql = QString("%1 limit %3 offset %2;").arg(sql).arg(startIndex).arg(resultCurrent);
+    } else if (dbType == DbType_SqlServer) {
+        //取第m条到第n条记录：select top (n-m+1) id from tablename where id not in (select top m-1 id from tablename)
+        //sql = QString("select %1 from %2 %3 order by %4").arg(selectColumn).arg(tableName).arg(whereSql).arg(orderSql);
+    } else if (dbType == DbType_Oracle) {
+        //暂时没有找到好办法
+    } else {
+        sql = QString("%1 limit %2,%3;").arg(sql).arg(startIndex).arg(resultCurrent);
+    }
+
+    return sql;
+}
+
 void DbPage::slot_receiveCount(quint32 count, double msec)
 {
     if (labResult != 0) {
@@ -294,10 +310,7 @@ void DbPage::slot_receiveCount(quint32 count, double msec)
         btnPre->setEnabled(true);
     }
 
-    tempSql = QString("select %1 from %2 %3 order by %4").arg(selectColumn).arg(tableName).arg(whereSql).arg(orderSql);
+    bindData(getPageSql());
-    sql = QString("%1 limit %2,%3;").arg(tempSql).arg(startIndex).arg(resultCurrent); //组织分页SQL语句
-
-    bindData(sql);
 }
 
 void DbPage::first()
@@ -305,8 +318,7 @@ void DbPage::first()
     if (pageCount > 1) {
         startIndex = 0;
         pageCurrent = 1;
-        sql = QString("%1 limit %2,%3;").arg(tempSql).arg(startIndex).arg(resultCurrent);
+        bindData(getPageSql());
-        bindData(sql);
         btnLast->setEnabled(true);
         btnNext->setEnabled(true);
     }
@@ -320,8 +332,7 @@ void DbPage::previous()
     if (pageCurrent > 1) {
         pageCurrent--;
         startIndex -= resultCurrent;
-        sql = QString("%1 limit %2,%3;").arg(tempSql).arg(startIndex).arg(resultCurrent);
+        bindData(getPageSql());
-        bindData(sql);
         btnLast->setEnabled(true);
         btnNext->setEnabled(true);
     }
@@ -337,8 +348,7 @@ void DbPage::next()
     if (pageCurrent < pageCount) {
         pageCurrent++;
         startIndex += resultCurrent;
-        sql = QString("%1 limit %2,%3;").arg(tempSql).arg(startIndex).arg(resultCurrent);
+        bindData(getPageSql());
-        bindData(sql);
         btnFirst->setEnabled(true);
         btnPre->setEnabled(true);
     }
@@ -354,8 +364,7 @@ void DbPage::last()
     if (pageCount > 0) {
         startIndex = (pageCount - 1) * resultCurrent;
         pageCurrent = pageCount;
-        sql = QString("%1 limit %2,%3;").arg(tempSql).arg(startIndex).arg(resultCurrent);
+        bindData(getPageSql());
-        bindData(sql);
         btnFirst->setEnabled(true);
         btnPre->setEnabled(true);
     }
@@ -514,7 +523,7 @@ void DbPage::select()
     }
 
     //开始分页绑定数据前,计算好总数据量以及行数
-    tempSql = QString("select count(%1) from %2 %3").arg(countName).arg(tableName).arg(whereSql);
+    QString sql = QString("select count(%1) from %2 %3").arg(countName).arg(tableName).arg(whereSql);
 
     //采用线程执行查询复合条件的记录行数
     DbCountThread *dbCountThread = new DbCountThread(this);
@@ -524,7 +533,7 @@ void DbPage::select()
 
     //设置数据库连接名称和查询语句,并启动线程
     dbCountThread->setConnName(connName);
-    dbCountThread->setSql(tempSql);
+    dbCountThread->setSql(sql);
     //从5.10开始不支持数据库在线程中执行
 #if (QT_VERSION <= QT_VERSION_CHECK(5,10,0))
     dbCountThread->start();

dbpage/dbpage.h

@@ -77,11 +77,14 @@ class DbPage : public QObject
     Q_OBJECT
 public:
     enum DbType {
-        DbType_Sqlite = 0,      //sqlite数据库
+        DbType_ODBC = 0,        //odbc数据源
-        DbType_MySql = 1,       //mysql数据库
+        DbType_Sqlite = 1,      //sqlite数据库
-        DbType_SqlServer = 3,   //sqlserver数据库
+        DbType_MySql = 2,       //mysql数据库
-        DbType_Access = 4,      //access数据库
+        DbType_PostgreSQL = 3,  //postgresql数据库
-        DbType_PostgreSQL = 5   //postgresql数据库
+        DbType_SqlServer = 4,   //sqlserver数据库
+        DbType_Oracle = 5,      //oracle数据库
+        DbType_KingBase = 6,    //人大金仓数据库
+        DbType_Other = 255      //其他数据库
     };
 
     static DbPage *Instance();
@@ -97,8 +100,6 @@ private:
     static QScopedPointer<DbPage> self;
 
     int startIndex;             //分页开始索引,每次翻页都变动
-    QString tempSql;            //临时SQL语句
-    QString sql;                //sql语句
     SqlQueryModel *queryModel;  //查询模型
 
     QLabel *labPageCount;       //总页数标签
@@ -143,6 +144,8 @@ private slots:
 private slots:
     //绑定sql语句到表格
     void bindData(const QString &sql);
+    //生成分页sql语句
+    QString getPageSql();
 
     //收到记录行数
     void slot_receiveCount(quint32 count, double msec);

videowidget/videowidget.cpp

@@ -568,6 +568,16 @@ QList<QRect> VideoWidget::getFaceRects() const
     return this->faceRects;
 }
 
+QSize VideoWidget::sizeHint() const
+{
+    return QSize(400, 300);
+}
+
+QSize VideoWidget::minimumSizeHint() const
+{
+    return QSize(40, 30);
+}
+
 void VideoWidget::updateImage(const QImage &image)
 {
     //拷贝图片有个好处,当处理器比较差的时候,图片不会产生断层,缺点是占用时间

videowidget/videowidget.h

@@ -204,6 +204,9 @@ public:
     QColor getFaceColor()           const;
     QList<QRect> getFaceRects()     const;
 
+    QSize sizeHint()                const;
+    QSize minimumSizeHint()         const;
+
 private slots:
     //接收图像并绘制
     void updateImage(const QImage &image);