SQLite, BLOB and UI Image

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Hi people!

It's possible to retrieve UI Image data from the BLOB field of a SQLite DB?

Thank you!

Gius

Answer 1

Answer by M-Hanssen · Apr 12, 2016 at 07:25 PM

A BLOB field in sql contains the binary data of an image. This binary data can be converted to a Texture2D in Unity and the conversion code is already inside the Unity API!

Take a look at this page for more guidelines: http://docs.unity3d.com/ScriptReference/Texture2D.LoadImage.html

Or this page to load raw texture data: http://docs.unity3d.com/ScriptReference/Texture2D.LoadRawTextureData.html

Just make sure you retreive the BLOB data from your database as a byte array!

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Bunny83 · Apr 13, 2016 at 12:10 AM 0

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Also make sure the image is in a supported format. Unity can only load .jpg and .png at runtime.

Giusort · Apr 14, 2016 at 02:19 PM 0

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Thank you Hanssen!

I tried ExampleScript you suggested and it works on a plane but not on a UI Image (with $$anonymous$$esh Renderer on it), as you can see on screenshot.

Where I'm wrong?

Thank you

$$anonymous$$

alt text

screenshot.png (339.7 kB)

Giusort · Apr 19, 2016 at 03:44 PM 0

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Solved this step simply changing the sprite:

GetComponent().sprite = Sprite.Create(tex, new Rect(0, 0, 64, 64), new Vector2(0.5f, 0.5f));

ramin1000 · Apr 11, 2017 at 02:31 PM 0

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What components must add to game object to above? above pic not clean. Thank you

Giusort ramin1000 · Apr 14, 2017 at 07:47 AM 0

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Hi Ra$$anonymous$$,

the important thing are mesh renderer and TestImg.cs, containing the function GetImage() below.

Answer 2

Answer by Giusort · May 04, 2016 at 12:29 PM

EDIT

I solved this way, assuming the query returns just one image:

 void GetImage() {
   string connectionString = "URI=file:" + string.Format(@"Assets/StreamingAssets/{0}", "SQLiteDB.db");
   IDbConnection dbcon = new SqliteConnection(connectionString);
   IDbCommand dbcmd;
   IDataReader reader;
   var tex = new Texture2D(64,64);
 
   dbcon.Open();
     string sql = "SELECT image FROM dabname where ID='1'";
 
     dbcmd = dbcon.CreateCommand();
     dbcmd.CommandText = sql;
     reader = dbcmd.ExecuteReader();
 
     while (reader.Read()) {
       byte[] img = (byte[])reader["image"];
       tex.LoadImage(img);
       // image 266x199
       GetComponent<Image>().sprite = Sprite.Create(tex, new Rect(0, 0, 266, 199), new Vector2(0.5f, 0.5f));
     }
 
 dbcon.Close ();
 reader.Dispose ();
 }

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charlesjunior · Mar 01, 2017 at 05:27 PM 0

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Thank you, it worked here. Helped me a lot.

solloranoharold123 · Mar 03, 2019 at 04:22 AM 0

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Could you help me. Step by Step procedure . I 'm newbie in using unity

solloranoharold123 · Mar 03, 2019 at 04:23 AM 0

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How do I display the image using Sprite.Create

solloranoharold123 · Mar 03, 2019 at 04:25 AM 0

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Its a Null after code it

Giusort solloranoharold123 · Mar 04, 2019 at 11:40 AM 0

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Probably because the tex var is null or empty. Start checking the SQLite DB and the blob field, then the DB connection.

Do you have some some error on dbcon.Open() ?

solloranoharold123 Giusort · Mar 07, 2019 at 02:53 PM 0

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There's no error on it. However the var tex is always null after I fetch an Image in SQLite.

Can you give me some examples oh how to load and save blob files in SQLIte.

unity_fiS-X9HAH5Am3A · Jan 29, 2020 at 07:00 PM 0

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the image shows a red question mark, even tho the byte array is not empry and i checked the boolean returned from tex.loadImage() returns true.

here's my code :

 private void readQuestionsFromDB(){
  
      string conn = "URI=file:" + Application.dataPath + "/quizdb.s3db"; //Path to database.
   IDbConnection dbconn;
   dbconn = (IDbConnection) new SqliteConnection(conn);
   dbconn.Open(); //Open connection to the database.
   IDbCommand dbcmd = dbconn.CreateCommand();
   string sqlQuery = "SELECT id, statement, answer, image " + "FRO$$anonymous$$ questions";
   dbcmd.CommandText = sqlQuery;
   IDataReader reader = dbcmd.ExecuteReader();
  
   while (reader.Read())
   {
      string statement = reader.GetString(1);
  
      answerint = reader.GetInt32(2);
  
      byte[] img = (byte[])reader["image"];
  
      Question q = new Question(statement, answer, img);
      questions.Add(q);
  
   }
   reader.Close();
   reader = null;
   dbcmd.Dispose();
   dbcmd = null;
   dbconn.Close();
   dbconn = null;
  
  }

and then i write this in the start method to display the array as an image :

  readQuestionsFromDB();  
  
     statement.text = questions[0].statement;
  
     Texture2D tex = new Texture2D(800,400); //image is 800/400
      tex.LoadImage(questions[0].image);
      image.GetComponent<Image>().sprite = Sprite.Create(tex, new Rect(0,0,tex.width,tex.height),new Vector2(0.5f, 0.5f));

please any help is appreciatied, thank you!

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SQLite, BLOB and UI Image

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