Qt操作Sqlite类封装，及命令行导入csv文件到Sqlite数据库

Posted 2022-08-10 特立独行的猫a

日常工作中，有时候需要对数据进行分析。如果能把待分析的数据导入sqllite数据库，是种不错的分析手段。或者需要导入其他数据库中的数据，做数据迁移用，比如可以把其他数据库中的表数据导出为csv文件，再把csv文件导入到sqllite。

用Qt来操作sqlite，可以做些带界面和图表的分析，使用很方便。

这里记录下导入csv文件到sqlite数据库的操作方法及sqlite的封装，留作备忘。

浏览sqllite数据库的客户端工具，我常用的是SQLiteSpy，仅4M大小，小巧简单。

 导入csv到sqlite

使用sqlite3.exe命令行工具。这个sqllite数据库带的有这个工具，可以直接下载使用。

操作的步骤：

1.打开数据库文件（前提存在db文件，且里面有相应的表结构）

 .\\sqlite3.exe .\\test.db

2.命令行操作

//查看数据库
.databases

// 查看数据
select * from tb_user;
1|yang|10

//查看表
.tables

3.导入csv文件到sqlite

这其中有个特别需要注意的问题是：csv文件的编码问题，必须为utf-8格式，utf-8-bom不行。

// 必须修改为,分隔符 
.separator ","

// 查看表结构
.schema tb_data

// 导入csv数据到表中 (前提 结构必须一致)                                                           
.import dbo_data.csv tb_data

以上操作即完成了csv文件数据入库的操作。

qt操作sqlite封装

Qt中操作数据库，.pro文件中，需要添加上：

QT += sql

#ifndef SQLITEDB_H
#define SQLITEDB_H

#include <QDir>
#include <QDate>
#include <QDateTime>
#include <QFileInfo>
#include <QString>
#include <QTime>
#include <QSqlDatabase>
#include <QSqlRecord>
#include <QSqlQuery>
#include <QVariant>

class sqliteDb

public:
    sqliteDb();
    ~sqliteDb();
public:
    bool setDbDir(QString dirPath);//设置数据库存放路径
    bool creatDbFile(QString dbName);//生成一个db文件
    bool reOpenSql(QString dbName);//打开连接
    bool closeSql();//关闭连接
    bool queryExec(QString dbName,QString sqlStr);//执行sql语句，不获取结果
    bool queryExec(QString dbName,QString sqlStr,QList<QHash<QString,QString>> &data);//执行sql语句，并获取结果
    bool getData(QString dbName,QString tableName,QHash<QString,QString> &data,QString sqlWhere=""); //获取数据
    bool getData(QString dbName,QString table,QList<QHash<QString,QString>> &data,QString sqlWhere=""); //获取数据
    bool getData(QString dbName,QString tableName,QHash<QString,QString> columndata,QList<QHash<QString,QString>> &data,QString sqlWhere=""); //获取数据
    bool addData(QString dbName,QString tableName,QHash<QString,QString> data);//增加
    bool delData(QString dbName,QString tableName,QString sqlWhere);//删除
    bool updateData(QString dbName,QString tableName,QHash<QString,QString> data,QString sqlWhere="");//修改

    bool queryExec(QString sqlStr);//执行sql语句，不获取结果
    bool queryExec(QString sqlStr,QList<QHash<QString,QString>> &data);//执行sql语句，并获取结果
    bool getData(QString tableName,QHash<QString,QString> &data,QString sqlWhere=""); //获取数据
    bool getData(QString table,QList<QHash<QString,QString>> &data,QString sqlWhere=""); //获取数据
    bool getData(QString tableName,QHash<QString,QString> columndata,QList<QHash<QString,QString>> &data,QString sqlWhere=""); //获取数据
    bool addData(QString tableName,QHash<QString,QString> data);//增加
    bool delData(QString tableName,QString sqlWhere);//删除
    bool updateData(QString tableName,QHash<QString,QString> data,QString sqlWhere="");//修改
    bool transaction();
    bool commit();
    QString getErrorSql();//获取错误的数据库语句
private:
    QSqlDatabase db;
    QString dbFilePath;//数据库路径
    QString dbDir; //数据库文件夹
    QString databaseName;//数据库名字
    QString errorSqlText;//错误语句
private:
    void errorSql(QString sql);//错误打印
;

#endif // SQLITEDB_H

#include "sqlitedb.h"

sqliteDb::sqliteDb()

    dbDir = QDir::currentPath() ;

sqliteDb::~sqliteDb()



//设置数据库存放路径
bool sqliteDb::setDbDir(QString dirPath)

    QDir dir(dirPath);
    if(dir.exists())
    
        dbDir = dirPath;
        return true;
    
    else
    
        return false;
    

//打开连接
bool sqliteDb::reOpenSql(QString dbName)

    QString fileName = (dbDir + "/"+dbName + ".db");
    if(!QFile::exists(fileName))
    
        qWarning("error,db not exist");
        return false;//数据库不存在
    
    QFileInfo file(fileName);
    if(file.suffix() != "db")
        return false;
    db = QSqlDatabase::database(dbName);
    if(!db.isValid())
    
        db = QSqlDatabase::addDatabase("QSQLITE",dbName);
        db.setDatabaseName(fileName);
        if (!db.open())
        
            return false;//打开失败
        
    
    dbFilePath = fileName;
    databaseName = dbName;//数据库名字
    return true;

//关闭连接
bool sqliteDb::closeSql()

    if(databaseName.isEmpty())
        return true;
    if(!QFile::exists(dbFilePath))
    
        return false;//数据库不存在
    
    db = QSqlDatabase::database(databaseName);
    if(!db.isValid())
    
        return true;
    
    db.close();
    db = QSqlDatabase::database();
    QSqlDatabase::removeDatabase(databaseName);
    databaseName = "";
    dbFilePath = "";
    return true;

//生成一个db文件
bool sqliteDb::creatDbFile(QString dbName)

    QString fileName = (dbDir + "/"+dbName + ".db");
    QFileInfo fileInfo(fileName);
    if(fileInfo.isFile())
        qWarning("db已存在，创建失败");
        return false;
    
    QFile file(fileName);
    if(file.open(QIODevice::WriteOnly))
    
        file.close();
    
    else
    
        return false;
    
    return true;

//错误打印
void sqliteDb::errorSql(QString sql)

    errorSqlText = sql;
    qCritical("%s",qPrintable(errorSqlText));
    //QString("数据库执行错误：%1 ")+sql.toUtf8().constData();

//获取错误的数据库语句
QString sqliteDb::getErrorSql()

    if(databaseName.isEmpty())
    
        return "db  not setting";//数据库未设置
    
    return errorSqlText;

//执行sql语句，不获取结果
bool sqliteDb::queryExec(QString dbName,QString queryStr)

    if(databaseName.isEmpty())
    
        if(!reOpenSql(dbName))
        
            return false;
        
    
    QSqlQuery query(QSqlDatabase::database(dbName, true));
    if(!query.exec(queryStr))
    
        errorSql(queryStr);
        return false;
    
    return  true;

//执行sql语句，并获取结果
bool sqliteDb::queryExec(QString dbName,QString queryStr,QList<QHash<QString,QString>> &data)

    data.clear();
    if(databaseName.isEmpty())
    
        if(!reOpenSql(dbName))
        
            return false;
        
    
    QSqlQuery query(QSqlDatabase::database(dbName, true));
    if(!query.exec(queryStr))
    
        errorSql(queryStr);
        return false;
    
    QSqlRecord rec = query.record();
    while(query.next())
    
        QHash<QString,QString> rowData;
        for(int i =0;i<rec.count();i++)
        
            QVariant::Type ty =  query.value(i).type();
            if( QVariant::Type::Date == ty)
            
                QDate temp = query.value(i).toDate();
                rowData[rec.fieldName(i)]=temp.toString("yyyy-MM-dd");
            
            else if( QVariant::Type::Time == ty)
            
                QTime temp = query.value(i).toTime();
                rowData[rec.fieldName(i)]=temp.toString("hh:mm:ss");
            
            else if( QVariant::Type::DateTime == ty)
            
                QDateTime temp = query.value(i).toDateTime();
                rowData[rec.fieldName(i)]=temp.toString("yyyy-MM-dd hh:mm:ss");
            
            else
                rowData[rec.fieldName(i)]=query.value(i).toString();
        
        data.append(rowData);
    
    return  true;

//获取数据
bool sqliteDb::getData(QString dbName,QString tableName,QHash<QString,QString> &data,QString sqlWhere)

    data.clear();
    QList<QHash<QString,QString>> dataList;
    if(!getData(dbName,tableName,dataList,sqlWhere))
    
        return false;
    
    if(dataList.count() > 0)
    
        data = dataList[0];
    
    return true;

//获取数据
bool sqliteDb::getData(QString dbName,QString tableName,QList<QHash<QString,QString>> &data,QString sqlWhere)

    QString queryStr="select * from "+tableName;
    if(!sqlWhere.isEmpty())
        queryStr+=" "+sqlWhere;
    if(!queryExec(dbName,queryStr,data))
    
        return  false;
    
    return  true;

//获取数据
bool sqliteDb::getData(QString dbName,QString tableName,QHash<QString,QString> columndata,QList<QHash<QString,QString>> &data,QString sqlWhere)

    QString colunmStr;
    if(columndata.count() == 0)
        colunmStr = "*";
    else
    
        QStringList keys = columndata.keys();
        for(auto key : keys)
        
            QString column = QString("%1 AS `%2`").arg(key).arg(columndata[key]);
            if(!colunmStr.isEmpty())
                colunmStr += ",";
            colunmStr += column;
        
    
    QString queryStr = QString("SELECT %1 FROM %2 %3").arg(colunmStr).arg(tableName).arg( sqlWhere);
    if(!queryExec(dbName,queryStr,data))
    
        return  false;
    
    return  true;

//增加
bool sqliteDb::addData(QString dbName,QString tableName,QHash<QString,QString> data)

    if(data.isEmpty())
        return false;
    QString queryStr="insert into "+tableName+" ";
    QString fieldStr="(",valueStr="values(";
    QHash<QString,QString>::iterator it;
    for ( it = data.begin(); it != data.end(); ++it )
    
        fieldStr+=it.key()+",";
        valueStr+="'"+it.value()+"',";
    
    fieldStr=fieldStr.left(fieldStr.length()-1);
    valueStr=valueStr.left(valueStr.length()-1);
    fieldStr+=")";
    valueStr+=")";
    queryStr+=fieldStr+" "+valueStr;
    if(!queryExec(dbName,queryStr))
    
        return false;
    
    return true;

//删除
bool sqliteDb::delData(QString dbName, QString tableName, QString sqlWhere)

    QString queryStr="delete from "+tableName;
    if(!sqlWhere.isEmpty())
        queryStr+=" "+sqlWhere;
    if(!queryExec(dbName,queryStr))
    
        return false;
    
    return true;

//修改
bool sqliteDb::updateData(QString dbName,QString tableName,QHash<QString,QString> data,QString sqlWhere)

    QString queryStr="update "+tableName+" ";
    QHash<QString,QString>::iterator it;
    QString setStr="set ";
    for ( it = data.begin(); it != data.end(); ++it )
    
        setStr+=it.key()+"='"+it.value()+"'";
        setStr+=",";
    
    setStr=setStr.left(setStr.length()-1);
    queryStr+=setStr;
    if(!sqlWhere.isEmpty())
        queryStr+=" "+sqlWhere;
    if(!queryExec(dbName,queryStr))
    
        return false;
    
    return true;

bool sqliteDb::transaction()

    if(databaseName.isEmpty())
        return false;
    return  db.transaction();

bool sqliteDb::commit()

    if(databaseName.isEmpty())
        return false;
    return  db.commit();

//执行sql语句，不获取结果
bool sqliteDb::queryExec(QString sqlStr)

    if(databaseName.isEmpty())
        return false;
    return  queryExec(databaseName,sqlStr);

//执行sql语句，并获取结果
bool sqliteDb::queryExec(QString sqlStr,QList<QHash<QString,QString>> &data)

    if(databaseName.isEmpty())
        return false;
    return  queryExec(databaseName,sqlStr,data);

//获取数据
bool sqliteDb::getData(QString tableName,QHash<QString,QString> &data,QString sqlWhere)

    if(databaseName.isEmpty())
        return false;
    return  getData(databaseName,tableName,data,sqlWhere);

//获取数据
bool sqliteDb::getData(QString table,QList<QHash<QString,QString>> &data,QString sqlWhere)

    if(databaseName.isEmpty())
        return false;
    return  getData(databaseName,table,data,sqlWhere);

//获取数据
bool sqliteDb::getData(QString tableName,QHash<QString,QString> columndata,QList<QHash<QString,QString>> &data,QString sqlWhere)

    if(databaseName.isEmpty())
        return false;
    return  getData(databaseName,tableName,columndata,data,sqlWhere);

//增加
bool sqliteDb::addData(QString tableName,QHash<QString,QString> data)

    if(databaseName.isEmpty())
        return false;
    return  addData(databaseName,tableName,data);

//删除
bool sqliteDb::delData(QString tableName,QString sqlWhere)

    if(databaseName.isEmpty())
        return false;
    return  delData(databaseName,tableName,sqlWhere);

//修改
bool sqliteDb::updateData(QString tableName,QHash<QString,QString> data,QString sqlWhere)

    if(databaseName.isEmpty())
        return false;
    return  updateData(databaseName,tableName,data,sqlWhere);

//

 使用举例

新建一个dbhelper类，作为具体的操作使用。

#include "dbhelper.h"
#include "cglobal.h"
Dbhelper::Dbhelper()

    db = new sqliteDb();
    init_table_0 = R"(
                 CREATE TABLE IF NOT EXISTS  tb_user (
                 id   INTEGER   PRIMARY KEY AUTOINCREMENT NOT NULL,
                 name CHAR (50) NOT NULL,
                 age  INTEGER
                 );)";


Dbhelper::~Dbhelper()

    if(db!= nullptr)
        db->closeSql();
        delete db;
    


int Dbhelper::createTable()

    db->setDbDir(DATA_PATH);
    bool ret = db->creatDbFile(DB_NAME);
    if(!ret)
        return -1;
    
    ret = db->reOpenSql(DB_NAME);
    if(ret)
        db->queryExec(QString::fromStdString(init_table_0));
        db->queryExec(QString::fromStdString(init_table_1));
        db->queryExec(QString::fromStdString(init_table_2));
    

    return 0;

简单使用：

    Dbhelper mydb;
    //若库不存在则自动创建库和表
    mydb.createTable();
    //打开数据库
    auto ret = mydb.db->reOpenSql(DB_NAME);
    if(!ret)
       qCritical("打开数据库失败");
    
    //插入一条测试数据
    QHash<QString,QString> data;
    data["name"] = "yang";
    data["age"] = "10";
    mydb.db->addData("tb_user",data);
    //......

Qt字节转换

#include "stringutils.h"
#include <QDebug>
#include <QTextCodec> //解决QBytearray中文乱码问题
#include <QDataStream>
//将1-9 a-f字符转化为对应的整数
 char ConvertHexChar(char ch)
    
        if((ch >= '0') && (ch <= '9'))
            return ch-0x30;
        else if((ch >= 'A') && (ch <= 'F'))
            return ch-'A'+10;
        else if((ch >= 'a') && (ch <= 'f'))
            return ch-'a'+10;
        else return (-1);
    
//将字符型进制转化为16进制
 QByteArray QString2Hex(QString str)
    
        QByteArray senddata;
        int hexdata,lowhexdata;
        int hexdatalen = 0;
        int len = str.length();
        senddata.resize(len/2);
        char lstr,hstr;
        for(int i=0; i<len; )
        
            hstr=str[i].toLatin1();   //字符型
            if(hstr == ' ')
            
                i++;
                continue;
            
            i++;
            if(i >= len)
                break;
            lstr = str[i].toLatin1();
            hexdata = ConvertHexChar(hstr);
            lowhexdata = ConvertHexChar(lstr);
            if((hexdata == 16) || (lowhexdata == 16))
                break;
            else
                hexdata = hexdata*16+lowhexdata;
            i++;
            senddata[hexdatalen] = (char)hexdata;
            hexdatalen++;
        
        senddata.resize(hexdatalen);
        return senddata;
    

//将接收的一串QByteArray类型的16进制,转化为对应的字符串16进制
 QString Hex2QString(QByteArray str)
 

     QDataStream out(&str,QIODevice::ReadWrite);   //将str的数据 读到out里面去
     QString buf;
     while(!out.atEnd())
     
           qint8 outChar = 0;
           out >> outChar;   //每次一个字节的填充到 outchar
           QString str = QString("%1").arg(outChar&0xFF,2,16,QLatin1Char('0')).toUpper() + QString("");   //2 字符宽度

           buf += str;
     
     return buf;
 
 QString ShowStr(QByteArray arr)
 

     //QDataStream out(&str,QIODevice::ReadWrite);   //将str的数据 读到out里面去
     //QString buf;
     //buf.prepend(str);

//     while(!out.atEnd())
//     
//           qint8 outChar = 0;
//           out >> outChar;   //每次一个字节的填充到 outchar
//           QString str = QString("%1").arg(outChar&0xFF,2,16,QLatin1Char('0')).toUpper() + QString(" ");   //2 字符宽度

//           buf += str;
//     
     QTextCodec *tc = QTextCodec::codecForName("GBK");
     QString tmpQStr = tc->toUnicode(arr);
     return tmpQStr;
 
//将接收的一串QByteArray类型的16进制,每2个16进制转化为1个字的16进制的字符串
 QString Convert4Hex(QByteArray str)
 

     QDataStream out(&str,QIODevice::ReadWrite);   //将str的数据 读到out里面去
     QString buf;
     while(!out.atEnd())
     
           qint16 outChar = 0;
           out>>outChar;   //每次一个字节的填充到 outchar
           QString str = QString("%1").arg(outChar&0xFFFF,4,16,QLatin1Char('0')).toUpper() + QString(" ");   //2 字符宽度

           buf += str;
     
     return buf;