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CREATE TABLE images (imgname text, img bytea);

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File file = new File("myimage.gif");

FileInputStream fis = new FileInputStream(file);

PreparedStatement ps = conn.prepareStatement("INSERT INTO images VALUES (?, ?)");

ps.setString(1, file.getName());

ps.setBinaryStream(2, fis, file.length());

ps.executeUpdate();

ps.close();

fis.close();

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PreparedStatement ps = con.prepareStatement("SELECT img FROM images WHERE imgname = ?");

ps.setString(1, "myimage.gif");

ResultSet rs = ps.executeQuery();

if (rs != null) {

    while (rs.next()) {

        byte[] imgBytes = rs.getBytes(1);

        // use the data in some way here

    }

    rs.close();

}

ps.close();

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CREATE TABLE imageslo (imgname text, imgoid oid);

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// All LargeObject API calls must be within a transaction block

conn.setAutoCommit(false);

// Get the Large Object Manager to perform operations with

LargeObjectManager lobj = ((org.postgresql.PGConnection)conn).getLargeObjectAPI();

// Create a new large object

int oid = lobj.create(LargeObjectManager.READ | LargeObjectManager.WRITE);

// Open the large object for writing

LargeObject obj = lobj.open(oid, LargeObjectManager.WRITE);

// Now open the file

File file = new File("myimage.gif");

FileInputStream fis = new FileInputStream(file);

// Copy the data from the file to the large object

byte buf[] = new byte[2048];

int s, tl = 0;

while ((s = fis.read(buf, 0, 2048)) > 0) {

    obj.write(buf, 0, s);

    tl += s;

}

// Close the large object

obj.close();

// Now insert the row into imageslo

PreparedStatement ps = conn.prepareStatement("INSERT INTO imageslo VALUES (?, ?)");

ps.setString(1, file.getName());

ps.setInt(2, oid);

ps.executeUpdate();

ps.close();

fis.close();

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// All LargeObject API calls must be within a transaction block

conn.setAutoCommit(false);

// Get the Large Object Manager to perform operations with

LargeObjectManager lobj = ((org.postgresql.PGConnection)conn).getLargeObjectAPI();

PreparedStatement ps = con.prepareStatement("SELECT imgoid FROM imageslo WHERE imgname = ?");

ps.setString(1, "myimage.gif");

ResultSet rs = ps.executeQuery();

if (rs != null) {

    while (rs.next()) {

        // Open the large object for reading

        int oid = rs.getInt(1);

        LargeObject obj = lobj.open(oid, LargeObjectManager.READ);

        // Read the data

        byte buf[] = new byte[obj.size()];

        obj.read(buf, 0, obj.size());

        // Do something with the data read here

        // Close the object

        obj.close();

    }

    rs.close();

}

ps.close();

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// Fielder define field info

type Fielder interface {

    String() string

    FieldType() int

    SetRaw(interface{}) error

    RawValue() interface{}

}

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type ByteArrayField []byte

// set value

func (e *ByteArrayField) SetRaw(value interface{}) error {

    if value == nil {

        return nil

    }

    switch d := value.(type) {

    case []byte:

        *e = d

    case string:

        *e = []byte(d)

    default:

        return fmt.Errorf("[ByteArrayField] unsupported type")

    }

    return nil

}

func (e *ByteArrayField) RawValue() interface{} {

    return *e

}

// specified type

func (f *ByteArrayField) FieldType() int {

    return orm.TypeTextField

}

func (f *ByteArrayField) String() string {

    return string(*f)

}

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type ImageModel struct{

    ImageName string `orm:"column(image_name)"`

    ImageData ByteArrayField `orm:"column(image_data);type(bytea)"`

}