c++ - Qt 5.9.1 SQLite Vacuum 出错？

Question

你好，我在 Qt C++ 中有一个小应用程序/SQLite 在 Qt 5.6.2 上运行良好，我确实升级到 Qt 5.9.1，问题是当我尝试 VACUUM 我的数据库时出现运行时错误请注意，除了 vacuum 之外，所有查询都有效 :( 并且它在 Qt 5.6.2 上正常工作

相关代码

QString msql::sqlExec(QString sqlCmd)
{
    query->clear();
    QString value;

    if (!query->exec(sqlCmd))
    {
        mDebug() << sqlCmd << query->lastError().text();
    }
    else if (!query->first())
    {
        //mDebug() << "not valid query: " << sqlCmd << query->isSelect();
        mDebug() << query->lastError().text();
        return "";
    }
    else
    {
        value = query->value(0).toString();
    }
    query->finish();
    return value;
}

和

bool msql::vacuum()
{
    QStringList tables = db.tables(QSql::AllTables);
    int x = 1;
    int y = tables.count();
    foreach (QString table, tables)
    {
        sqlExec(QString("VACUUM `%1`").arg(table));
        emit progress(QString("Optimizing table %1/%2:%3").arg(x).arg(y).arg(table));
        if (killLoopFlag_)
            return false;
        x++;
    }
    return true;
}

我得到这个错误

---

Debug:[2017-07-17 02:51 AM] "VACUUM `visits`" "unknown database `visits` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `investigations`" "unknown database `investigations` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `credentials`" "unknown database `credentials` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `siblings`" "unknown database `siblings` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `surgicalNotes`" "unknown database `surgicalNotes` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `metadata`" "unknown database `metadata` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `drugs`" "unknown database `drugs` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `deceased`" "unknown database `deceased` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `visitPrices`" "unknown database `visitPrices` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `conditions`" "unknown database `conditions` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `conditions_patients`" "unknown database `conditions_patients` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `perinatal`" "unknown database `perinatal` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `development`" "unknown database `development` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `obgyn`" "unknown database `obgyn` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `patients`" "unknown database `patients` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `agendaView`" "unknown database `agendaView` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `registerView`" "unknown database `registerView` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `sqlite_master`" "unknown database `sqlite_master` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `SERVICES`" "unknown database `SERVICES` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `defaultDoses`" "unknown database `defaultDoses` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `allergies`" "unknown database `allergies` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `complaints`" "unknown database `complaints` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `diagnoses`" "unknown database `diagnoses` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `dictionary`" "unknown database `dictionary` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `doses`" "unknown database `doses` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `surgeries`" "unknown database `surgeries` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `investigations`" "unknown database `investigations` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `jobs`" "unknown database `jobs` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `places`" "unknown database `places` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `placeOfBirth`" "unknown database `placeOfBirth` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `expander`" "unknown database `expander` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `drugs`" "unknown database `drugs` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `diet`" "unknown database `diet` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `sqlite_master`" "unknown database `sqlite_master` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `drugsIndex`" "unknown database `drugsIndex` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `metadata`" "unknown database `metadata` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 
Debug:[2017-07-17 02:51 AM] "VACUUM `sqlite_master`" "unknown database `sqlite_master` Unable to execute statement" (..\qtemr\msql.cpp:16) class QString __thiscall msql::sqlExec(class QString) 

Answer 1

VACUUM 不应用于特定表，而是应用于整个数据库。您过去常常附加被 VACUUM 命令忽略的表名。自升级 Qt 以来，您也升级了 SQLite 驱动程序。来自SQLite site :

Compatibility Warning: The ability to vacuum attached databases was added in version 3.15.0 (2016-10-14). Prior to that, a schema-name added to the VACUUM statement would be silently ignored and the "main" schema would be vacuumed.

这里的“Schema-name”是数据库的名称。所以你可以只保留一个字符串

sqlExec("VACUUM");