qt中使用sqlite存储数据

Posted 2020-10-12 思而不学

一、sqilte的安装

在Windows上安装SQLite:

请访问 SQLite 下载页面，从 Windows 区下载预编译的二进制文件。

您需要下载 sqlite-tools-win32-*.zip 和 sqlite-dll-win32-*.zip 压缩文件。

创建文件夹 C:\sqlite，并在此文件夹下解压上面两个压缩文件，将得到 sqlite3.def、sqlite3.dll 和 sqlite3.exe 文件。

添加 C:\sqlite 到 PATH 环境变量，最后在命令提示符下，使用 sqlite3 命令，将显示如下结果。

C:\>sqlite3
SQLite version 3.7.15.2 2013-01-09 11:53:05
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite>

 

二、sqilte的连接

 1 /* 名称：Connectmysqlite
 2  * 功能：确认数据库连接
 3  * 输入：_database需要连接的数据库
 4  * 返回：true连接成功，false连接失败
 5  */
 6 bool MySql::ConnectMySqlite(QSqlDatabase &_database)
 7 {
 8     if(QSqlDatabase::contains(mySqlConnectName))
 9         _database = QSqlDatabase::database(mySqlConnectName);
10     else
11         _database = QSqlDatabase::addDatabase("QSQLITE", mySqlConnectName);
12     _database.setDatabaseName(mySqlName);
13 
14     if(!_database.open()) {
15         qDebug()<<"ConnectMySqlite:SQLite connected failed.";
16         return false;
17     }
18 
19     return true;
20 }

ConnectMySqlite

 

三、qt中QSqlQuery使用

 1 /* 名称：UpdateAlertTableValue
 2  * 功能：更新myAlertTable结构
 3  * 输入：无
 4  * 返回：0成功，-1数据库连接失败-2数据更新不全
 5  */
 6 int MySql::UpdateAlertTableValue()
 7 {
 8     QString sqlSelect = QString("select * from %1").arg(mySqlAlertTableName);
 9     int i=0;
10     bool status = false;
11     QSqlDatabase myDataBase;
12     status = ConnectMySqlite(myDataBase);
13     if(!status)
14     {
15         qDebug()<<"UpdateAlertTableValue>>ConnectMySqlite failed.";
16         return -1;
17     }
18 
19     if(!myDataBase.open())
20         return -1;
21 
22     QSqlQuery query(myDataBase);
23     query.prepare(sqlSelect);
24     if(!query.exec()) {
25         qDebug()<<"exec error:"<<query.lastError();
26     } else {
27         for(i =0;i<6 && query.next();++i)
28         {
29             myAlertTable[i].id = query.value(0).toInt();
30             myAlertTable[i].alertName = query.value(1).toString();
31             myAlertTable[i].alertValue= query.value(2).toInt();
32             myAlertTable[i].alertInterval = query.value(3).toInt();
33             myAlertTable[i].relayStatus0 = query.value(4).toInt();
34             myAlertTable[i].relayStatus1 = query.value(5).toInt();
35             myAlertTable[i].relayStatus2 = query.value(6).toInt();
36             myAlertTable[i].relayStatus3 = query.value(7).toInt();
37             myAlertTable[i].diffQuitiety = query.value(8).toInt();
38         }
39     }
40 
41     if(i!=6)
42         return -2;
43     return 0;
44 }

UpdateAlertTableValue

 

四、qt中QSqlQueryModel使用

 1 /* 名称：ExportSqliteDataWithModel
 2  * 功能：导出为excel
 3  * 输入：无
 4  * 返回：无
 5  */
 6 void MySql::ExportSqliteDataWithModel(QDateTime _startDate, QDateTime _endDate, QString filePath)
 7 {
 8     QString path = filePath;
 9     QString sqlSelect = QString("select * from %1 where %1.sampleDate between ‘%2‘ and ‘%3‘ ")
10             .arg(mySqlStormTableName)
11             .arg(_startDate.toString("yyyy-MM-dd hh:mm:ss"))
12             .arg(_endDate.toString("yyyy-MM-dd hh:mm:ss"));
13 
14     bool status = false;
15     QSqlDatabase myDataBase;
16     status = ConnectMySqlite(myDataBase);
17     if(!status)
18     {
19         qDebug()<<"ExportSqliteDataWithModel>>ConnectMySqlite failed.";
20         return;
21     }
22 
23     if(!myDataBase.open())
24         return;
25 
26     QSqlQueryModel *model = new QSqlQueryModel(this);
27     QFile file(path);
28     QTextStream out(&file);
29 
30     if(!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
31         qDebug()<<file.errorString();
32         return;
33     } else {
34         uint excelMaxrows = 1000000;
35         model->setQuery(sqlSelect, myDataBase);
36 
37         while(model->canFetchMore())
38         {
39             model->fetchMore();
40         }
41         qDebug()<<"path:"<<path<<"filename:"<<file.fileName();
42 
43         uint tableRows = model->rowCount();
44         uint64_t row = 0;
45         for(uint i=1;row<tableRows;++i)
46         {
47             if(i!=1)                //如果数据超过1000000行，创建新文件
48             {
49                 path = path.replace(".xls",QString("(%1).xls").arg(i));
50                 file.setFileName(path);
51                 out.setDevice(&file);
52                 if(!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
53                     qDebug()<<file.errorString();
54                     return;
55                 }
56             }
57 
58             for(;row<tableRows && row<excelMaxrows*i;++row)
59             {
60                 QModelIndex indexId = model->index(row,0);
61                 QModelIndex indexHighValue = model->index(row,1);
62                 QModelIndex indexLowValue = model->index(row,2);
63                 QModelIndex indexTempValue = model->index(row,3);
64                 QModelIndex indexSampleData = model->index(row,4);
65 
66                 out<<indexId.data().toInt()<<"\t"<<indexHighValue.data().toDouble()
67                   <<"\t"<<indexLowValue.data().toDouble()<<"\t"<<indexTempValue.data().toDouble()
68                  <<"\t"<<indexSampleData.data().toString();
69                 out<<"\n";
70             }
71             file.close();
72         }
73     }
74 }

ExportSqliteDataWithModel