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SQLite BLOB to QString

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  • CryptixDEC Offline
    CryptixDEC Offline
    CryptixDE
    wrote on last edited by CryptixDE
    #1

    I have a SQLite database with a field typed BLOB (Binary),
    but this field contains normal text.
    I want to have this field value as QString.
    I already was able to get the value as ByteArray.

    Here is my current code:

    QSqlQuery query("SELECT value FROM Tabelle WHERE key='token'", db);
    query.first();
    QString data= query.value(0).toString();
    

    But what I get is: "\""

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    • mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Hi
      Did you try to convert to string via ByteArray ?
      Here you do directly from QVariant

      1 Reply Last reply
      0
      • CryptixDEC Offline
        CryptixDEC Offline
        CryptixDE
        wrote on last edited by CryptixDE
        #3

        How do I do this?
        I searched for it but I couldn't find a way to do this via QVariant

        Edit: Yes, I did, the SQLite result is aQVariant

        mrjjM 1 Reply Last reply
        0
        • CryptixDEC CryptixDE

          How do I do this?
          I searched for it but I couldn't find a way to do this via QVariant

          Edit: Yes, I did, the SQLite result is aQVariant

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #4

          @CryptixDE
          Hi
          did not check if even possible but i meant like
          QByteArray data= query.value(0).toByteArray();
          QString datastr(data);

          CryptixDEC 1 Reply Last reply
          0
          • F Offline
            F Offline
            fsilva
            wrote on last edited by
            #5

            This will depend a lot on the actual data that is present in the BLOB column ("text" can mean many many different things at the binary level).

            But for a more generic case, something like this should work:

            QByteArray strData = query.value(0).toByteArray();
            QString str = QString::fromUtf8(strData);
            
            1 Reply Last reply
            1
            • mrjjM mrjj

              @CryptixDE
              Hi
              did not check if even possible but i meant like
              QByteArray data= query.value(0).toByteArray();
              QString datastr(data);

              CryptixDEC Offline
              CryptixDEC Offline
              CryptixDE
              wrote on last edited by CryptixDE
              #6

              @mrjj Yea, I tried this, but this not returns the string for me, it just returns "\""

              @fsilva Thank you, I'll try it asap :)

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              0
              • F Offline
                F Offline
                fsilva
                wrote on last edited by
                #7

                You need to know the encoding of your string (I assumed UTF-8 but if you are getting only the quotation marks it's most likely UTF-16) and use the appropriate QString constructor or from**** static method.

                CryptixDEC 1 Reply Last reply
                2
                • F fsilva

                  You need to know the encoding of your string (I assumed UTF-8 but if you are getting only the quotation marks it's most likely UTF-16) and use the appropriate QString constructor or from**** static method.

                  CryptixDEC Offline
                  CryptixDEC Offline
                  CryptixDE
                  wrote on last edited by
                  #8

                  @fsilva so fromUtf16 instead of fromUtf8 should work?

                  1 Reply Last reply
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                  • CryptixDEC Offline
                    CryptixDEC Offline
                    CryptixDE
                    wrote on last edited by
                    #9

                    Yea, I solved this issue by using the hex value

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