我尝试将postgresql
数据库与WEKA
中的Eclipse
连接起来。
当我运行主要版本时,我得到exception
:
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.
这是我的DatabaseUtils.props.postgresql文件的一部分:
# 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; --> nominal
boolean, getBoolean() = 1; --> nominal
double, getDouble() = 2; --> numeric
# byte, getByte() = 3; --> numeric
# short, getByte()= 4; --> numeric
int, getInteger() = 5; --> numeric
# long, getLong() = 6; --> numeric
# float, getFloat() = 7; --> numeric
# date, getDate() = 8; --> date
# text, getString() = 9; --> string
# time, getTime() = 10; --> date
# timestamp, getTime() = 11; --> 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
这是我主要方法中的代码:
InstanceQuery query = new InstanceQuery();
query.setUsername("username");
query.setPassword("password");
query.setQuery("SELECT * FROM database ORDER BY \"id\"");
Instances data = query.retrieveInstances();
有人可以告诉我为什么我仍然得到例外吗?
答案 0 :(得分:0)
尝试将getter添加到DatabaseUtils.props.postgresql
答案 1 :(得分:0)
我将DatabaseUtils.props代码更改为:
# 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: 11885 $
# JDBC driver (comma-separated list)
jdbcDriver=org.postgresql.Driver
# database URL
jdbcURL=jdbc:postgresql://localhost:5432/datamining
# specific data types
# string, getString() = 0; --> nominal
# boolean, getBoolean() = 1; --> nominal
# double, getDouble() = 2; --> numeric
# byte, getByte() = 3; --> numeric
# short, getByte()= 4; --> numeric
# int, getInteger() = 5; --> numeric
# long, getLong() = 6; --> numeric
# float, getFloat() = 7; --> numeric
# date, getDate() = 8; --> date
# text, getString() = 9; --> string
# time, getTime() = 10; --> date
# timestamp, getTime() = 11; --> 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
varchar=0
text=0
float4=7
float8=2
int4=5
oid=5
timestamp=8
date=8
bool=1
int2=5
int8=2
numeric=2
bpchar=9
现在它正在运作。您还应该检查eclipse的java版本是否与driver.jar的java版本相同。否则你会得到这个例外:
java.lang.NoClassDefFoundError: java/time/temporal/TemporalField