WEKA: java.lang.IllegalArgumentException: Unknown data type: int4
<p>I'm trying to connect my <code>postgresql</code> database with <code>WEKA</code> in <code>Eclipse</code>. </p>

<p>When i run the main I get this <code>exception</code>:</p>

<pre><code>Exception in thread "main" java.lang.IllegalArgumentException: Unknown data type: int4. Add entry in weka/experiment/DatabaseUtils.props.
If the type contains blanks, either escape them with a backslash or use underscores instead of blanks.
</code></pre>

<ul>
<li>I downloaded WEKA 3-6-14</li>
<li>I unzipped the weka.jar</li>
<li>I changed the lines of the jdbc url and the jdbc driver in the file weka/experiment/DatabaseUtils.props.postgresql</li>
<li>I added the data types that I use in my database</li>
<li>I renamed the DatabaseUtils.props.postgresql file to DatabaseUtils.props</li>
</ul>

<p>This is a segment of my DatabaseUtils.props.postgresql file:</p>

<pre><code># Database settings for PostgreSQL 7.4
#
# General information on database access can be found here:
# http://weka.wikispaces.com/Databases
#
# url:     http://www.postgresql.org/
# jdbc:    http://jdbc.postgresql.org/
# author:  Fracpete (fracpete at waikato dot ac dot nz)
# version: $Revision: 11887 $

# JDBC driver (comma-separated list)
jdbcDriver=org.postgresql.Driver

# database URL
jdbcURL=jdbc:postgresql://localhost:5432/datamining

# specific data types
string, getString() = 0;    --&gt; nominal
boolean, getBoolean() = 1;  --&gt; nominal
double, getDouble() = 2;    --&gt; numeric
# byte, getByte() = 3;        --&gt; numeric
# short, getByte()= 4;        --&gt; numeric
int, getInteger() = 5;      --&gt; numeric
# long, getLong() = 6;        --&gt; numeric
# float, getFloat() = 7;      --&gt; numeric
# date, getDate() = 8;        --&gt; date
# text, getString() = 9;      --&gt; string
# time, getTime() = 10;       --&gt; date
# timestamp, getTime() = 11;  --&gt; date

# PostgreSQL data types to Java classes information can be found at:
# http://www.postgresql.org/message-id/AANLkTinsk4rwT7v-751bwQkgTN1rkA=8uE-jk69nape-@mail.gmail.com
text=0
boolean=1
double=2
int4=5
</code></pre>

<p>This is the code in my main method:</p>

<pre><code>InstanceQuery query = new InstanceQuery();
    query.setUsername("username");
    query.setPassword("password");
    query.setQuery("SELECT * FROM database ORDER BY \"id\"");
    Instances data = query.retrieveInstances();
</code></pre>

<p>Can someone please tell me why I'm still getting the exception? </p>