databaseutils.html

weka是机器学习和数据挖掘领域最有影响力的开源项目之一

<PRE>
public static final int <B>FLOAT</B></PRE>
<DL>
<DD>Type mapping for FLOAT used for reading experiment results
<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../constant-values.html#weka.experiment.DatabaseUtils.FLOAT">Constant Field Values</A></DL>
</DL>
<HR>

<A NAME="DATE"><!-- --></A><H3>
DATE</H3>
<PRE>
public static final int <B>DATE</B></PRE>
<DL>
<DD>Type mapping for DATE used for reading experiment results
<P>
<DL>
<DT><B>See Also:</B><DD><A HREF="../../constant-values.html#weka.experiment.DatabaseUtils.DATE">Constant Field Values</A></DL>
</DL>

<!-- ========= CONSTRUCTOR DETAIL ======== -->

<A NAME="constructor_detail"><!-- --></A>
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<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Constructor Detail</B></FONT></TH>
</TR>
</TABLE>

<A NAME="DatabaseUtils()"><!-- --></A><H3>
DatabaseUtils</H3>
<PRE>
public <B>DatabaseUtils</B>()
              throws java.lang.Exception</PRE>
<DL>
<DD>Reads properties and sets up the database drivers
<P>
<DL>

<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if an error occurs</DL>
</DL>

<!-- ============ METHOD DETAIL ========== -->

<A NAME="method_detail"><!-- --></A>
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<B>Method Detail</B></FONT></TH>
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<A NAME="translateDBColumnType(java.lang.String)"><!-- --></A><H3>
translateDBColumnType</H3>
<PRE>
public int <B>translateDBColumnType</B>(java.lang.String&nbsp;type)</PRE>
<DL>
<DD>translates the column data type string to an integer value that indicates
 which data type / get()-Method to use in order to retrieve values from the
 database (see DatabaseUtils.Properties, InstanceQuery()). Blanks in the type 
 are replaced with underscores "_", since Java property names can't contain blanks.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>type</CODE> - the column type as retrieved with 
                        java.sql.MetaData.getColumnTypeName(int)
<DT><B>Returns:</B><DD>an integer value that indicates
                        which data type / get()-Method to use in order to 
                        retrieve values from the</DL>
</DD>
</DL>
<HR>

<A NAME="arrayToString(java.lang.Object[])"><!-- --></A><H3>
arrayToString</H3>
<PRE>
public static java.lang.String <B>arrayToString</B>(java.lang.Object[]&nbsp;array)</PRE>
<DL>
<DD>Converts an array of objects to a string by inserting a space
 between each element. Null elements are printed as ?
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>array</CODE> - the array of objects
<DT><B>Returns:</B><DD>a value of type 'String'</DL>
</DD>
</DL>
<HR>

<A NAME="typeName(int)"><!-- --></A><H3>
typeName</H3>
<PRE>
public static java.lang.String <B>typeName</B>(int&nbsp;type)</PRE>
<DL>
<DD>Returns the name associated with a SQL type.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>type</CODE> - the SQL type
<DT><B>Returns:</B><DD>the name of the type</DL>
</DD>
</DL>
<HR>

<A NAME="databaseURLTipText()"><!-- --></A><H3>
databaseURLTipText</H3>
<PRE>
public java.lang.String <B>databaseURLTipText</B>()</PRE>
<DL>
<DD>Returns the tip text for this property
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>tip text for this property suitable for
                        displaying in the explorer/experimenter gui</DL>
</DD>
</DL>
<HR>

<A NAME="getDatabaseURL()"><!-- --></A><H3>
getDatabaseURL</H3>
<PRE>
public java.lang.String <B>getDatabaseURL</B>()</PRE>
<DL>
<DD>Get the value of DatabaseURL.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>Value of DatabaseURL.</DL>
</DD>
</DL>
<HR>

<A NAME="setDatabaseURL(java.lang.String)"><!-- --></A><H3>
setDatabaseURL</H3>
<PRE>
public void <B>setDatabaseURL</B>(java.lang.String&nbsp;newDatabaseURL)</PRE>
<DL>
<DD>Set the value of DatabaseURL.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>newDatabaseURL</CODE> - Value to assign to DatabaseURL.</DL>
</DD>
</DL>
<HR>

<A NAME="debugTipText()"><!-- --></A><H3>
debugTipText</H3>
<PRE>
public java.lang.String <B>debugTipText</B>()</PRE>
<DL>
<DD>Returns the tip text for this property
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>tip text for this property suitable for
                        displaying in the explorer/experimenter gui</DL>
</DD>
</DL>
<HR>

<A NAME="setDebug(boolean)"><!-- --></A><H3>
setDebug</H3>
<PRE>
public void <B>setDebug</B>(boolean&nbsp;d)</PRE>
<DL>
<DD>Sets whether there should be printed some debugging output to stderr or not
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>d</CODE> - true if output should be printed</DL>
</DD>
</DL>
<HR>

<A NAME="getDebug()"><!-- --></A><H3>
getDebug</H3>
<PRE>
public boolean <B>getDebug</B>()</PRE>
<DL>
<DD>Gets whether there should be printed some debugging output to stderr or not
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>true if output should be printed</DL>
</DD>
</DL>
<HR>

<A NAME="usernameTipText()"><!-- --></A><H3>
usernameTipText</H3>
<PRE>
public java.lang.String <B>usernameTipText</B>()</PRE>
<DL>
<DD>Returns the tip text for this property
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>tip text for this property suitable for
                        displaying in the explorer/experimenter gui</DL>
</DD>
</DL>
<HR>

<A NAME="setUsername(java.lang.String)"><!-- --></A><H3>
setUsername</H3>
<PRE>
public void <B>setUsername</B>(java.lang.String&nbsp;username)</PRE>
<DL>
<DD>Set the database username
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>username</CODE> - Username for Database.</DL>
</DD>
</DL>
<HR>

<A NAME="getUsername()"><!-- --></A><H3>
getUsername</H3>
<PRE>
public java.lang.String <B>getUsername</B>()</PRE>
<DL>
<DD>Get the database username
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>Database username</DL>
</DD>
</DL>
<HR>

<A NAME="passwordTipText()"><!-- --></A><H3>
passwordTipText</H3>
<PRE>
public java.lang.String <B>passwordTipText</B>()</PRE>
<DL>
<DD>Returns the tip text for this property
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>tip text for this property suitable for
                        displaying in the explorer/experimenter gui</DL>
</DD>
</DL>
<HR>

<A NAME="setPassword(java.lang.String)"><!-- --></A><H3>
setPassword</H3>
<PRE>
public void <B>setPassword</B>(java.lang.String&nbsp;password)</PRE>
<DL>
<DD>Set the database password
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>password</CODE> - Password for Database.</DL>
</DD>
</DL>
<HR>

<A NAME="getPassword()"><!-- --></A><H3>
getPassword</H3>
<PRE>
public java.lang.String <B>getPassword</B>()</PRE>
<DL>
<DD>Get the database password
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>Password for Database.</DL>
</DD>
</DL>
<HR>

<A NAME="connectToDatabase()"><!-- --></A><H3>
connectToDatabase</H3>
<PRE>
public void <B>connectToDatabase</B>()
                       throws java.lang.Exception</PRE>
<DL>
<DD>Opens a connection to the database
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if an error occurs</DL>
</DD>
</DL>
<HR>

<A NAME="disconnectFromDatabase()"><!-- --></A><H3>
disconnectFromDatabase</H3>
<PRE>
public void <B>disconnectFromDatabase</B>()
                            throws java.lang.Exception</PRE>
<DL>
<DD>Closes the connection to the database.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if an error occurs</DL>
</DD>
</DL>
<HR>

<A NAME="isConnected()"><!-- --></A><H3>
isConnected</H3>
<PRE>
public boolean <B>isConnected</B>()</PRE>
<DL>
<DD>Returns true if a database connection is active.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>a value of type 'boolean'</DL>
</DD>
</DL>
<HR>