问题
Hi I tried to store and retrieve image to and from sqlite database. My following codes is not working. I'm not sure what wrong I did. Please help. I created the database table as follows:
db = openOrCreateDatabase("StudentDB", Context.MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS student(rollno VARCHAR,
name VARCHAR,photo BLOB,marks VARCHAR);");
then I inserted the fields
db.execSQL("INSERT INTO student VALUES('"
+ editRollno.getText() + "','"
+ editName.getText() + "','"
+ imageInByte + "','"
+ editMarks.getText()
+ "');");
where imageInByte is a byte[] variable which was assigned before from gallery as follows:
ByteArrayOutputStream stream = new ByteArrayOutputStream();
yourImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
imageInByte = stream.toByteArray();
when I tried to retrieve an image from db it fails:
Cursor c = db.rawQuery("SELECT * FROM student WHERE rollno='"
+ editRollno.getText() + "'", null);
if (c.moveToFirst()) {
editName.setText(c.getString(1));
editMarks.setText(c.getString(2));
byte[] image = c.getBlob(3);
ByteArrayInputStream imageStream = new ByteArrayInputStream(image);
theImage = BitmapFactory.decodeStream(imageStream);
imageView2.setImageBitmap(theImage);
}
回答1:
You cannot simply treat byte arrays as text. (To use blobs with execSQL, you would have to use blob literals.)
To insert a row, use the insert method, which has support for byte arrays.
来源：https://stackoverflow.com/questions/28811674/android-cursor-getblob-not-working