How to Store and Retrieve Image on SQLite: Difference between revisions

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{{LangSwitch}}
{{LangSwitch}}
[[Category:snippets]]
 
[[Category:HowTo]]
Images or any files can be stored in a database. Here is one way to do it using the following steps:
Images or any files can be stored in a database. Here is one way to do it using the following steps:


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# Store QByteArray as a Binary Large Object in database.
# Store QByteArray as a Binary Large Object in database.


For example :
For example:


<code>
<code>
QFile file(fileName);
QFile file(fileName);
if (!file.open(QIODevice::ReadOnly)) return;
if (!file.open(QIODevice::ReadOnly)) return;
QByteArray byteArray = file.readAll();
QByteArray byteArray = file.readAll();


QSqlQuery query;
QSqlQuery query;
query.prepare("INSERT INTO imgtable (imgdata) VALUES (?)");
query.prepare("INSERT INTO imgtable (imgdata) VALUES (?)");
query.addBindValue(byteArray);
query.addBindValue(byteArray);
query.exec();
query.exec();
</code>
</code>


Now, the image/file can be retrieved like any other data
Now, the image/file can be retrieved like any other data
<code>
<code>
QSqlQuery query("SELECT imgdata FROM imgtable");
QSqlQuery query("SELECT imgdata FROM imgtable");
query.next();
query.next();
QByteArray array = query.value(0).toByteArray();
QByteArray array = query.value(0).toByteArray();
</code>
</code>


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</code>
</code>


It is done. Now the pixmap can be used in a Button as icon or in label etc.
It is done. Now the pixmap can be used in a {{class|QPushButton}} as icon or in label etc.
 
[[Category:Snippets]]
[[Category:HowTo]]

Revision as of 15:34, 16 November 2015

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Images or any files can be stored in a database. Here is one way to do it using the following steps:

  1. Read the system file into a QByteArray.
  2. Store QByteArray as a Binary Large Object in database.

For example:

QFile file(fileName);
if (!file.open(QIODevice::ReadOnly)) return;
QByteArray byteArray = file.readAll();

QSqlQuery query;
query.prepare("INSERT INTO imgtable (imgdata) VALUES (?)");
query.addBindValue(byteArray);
query.exec();

Now, the image/file can be retrieved like any other data

QSqlQuery query("SELECT imgdata FROM imgtable");
query.next();
QByteArray array = query.value(0).toByteArray();

Creating a QPixmap from QByteArray :

 QPixmap pixmap = QPixmap();
 pixmap.loadFromData(array);

It is done. Now the pixmap can be used in a QPushButton as icon or in label etc.