Pgsql越来越强大了。小项目输出log到sqlite是挺好的，大东西尤其是要长期运行的程序还是输出到Postgresql比较，也更适用于寄宿在Windows Service这种将当前目录视为System32的场合。

直接上配置文件。

<!--定义输出到Postgresql数据库中，用于Windows Service这种无法正确识别程序当前目录从而无法使用相对路径的场合-->
    <appender name="AdoNetAppender_Postgresql_All" type="log4net.Appender.AdoNetAppender">
      <bufferSize value="10"/>
      <connectionType value="Npgsql.NpgsqlConnection,Npgsql"/>
      <!--Postgresql连接字符串-->
      <connectionString value="Server=127.0.0.1;Port=5432;User Id=postgres;Password=tm;Database=postgres;"/>
      <!--Postgresql插入字符串-->
      <!--如果想在Postgresql中保持字段字有大小写，要加入"
          但是由于我用了Ormlite，所以不需要了
      <commandText value="INSERT INTO "Log" 
                   ("AppDomain","AspnetCache","AspnetContext","AspnetRequest","AspnetSession","Logger","Date","Identity","Level","Location","Exception","Message","Thread","NDC","StackTraceDetail","UserName","UTCDate")
                    VALUES
                    (:AppDomain,:AspnetCache,:AspnetContext,:AspnetRequest,:AspnetSession,:Logger,:Date,:Identity,:Level,:Location,:Exception,:Message,:Thread,:NDC,:StackTraceDetail,:UserName,:UTCDate)"/>
      -->
      <!--为了配合Ormlite生成的表，中间加上下划线-->
         <commandText value="INSERT INTO log
         (app_domain,aspnet_cache,aspnet_context,aspnet_request,aspnet_session,logger,date_time,identity,level,location,exception,message,thread,ndc,stack_trace_detail,user_name,utc_date)
          VALUES
          (:AppDomain,:UTCDate)"/>
      <parameter>
        <parameterName value="AppDomain"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%appdomain"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="AspnetCache"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%aspnet-cache"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="AspnetContext"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%aspnet-context"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="AspnetRequest"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%aspnet-request"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="AspnetSession"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%aspnet-session"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Logger"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%logger"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Date"/>
        <dbType value="DateTime"/>
        <layout type="log4net.Layout.RawTimeStampLayout"/>
      </parameter>
      <parameter>
        <parameterName value="Identity"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%identity"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Level"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%level"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Location"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%location"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Exception"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.ExceptionLayout">
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Message"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%message"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="Thread"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%thread"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="NDC"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%ndc"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="StackTraceDetail"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%stacktracedetail{10}"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="UserName"/>
        <dbType value="String"/>
        <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%username"/>
        </layout>
      </parameter>
      <parameter>
        <parameterName value="UTCDate"/>
        <dbType value="DateTime"/>
        <layout type="log4net.Layout.RawUtcTimeStampLayout"/>
      </parameter>
    </appender>

-- Table: log

-- DROP TABLE log;

CREATE TABLE log
(
  id serial NOT NULL,date_time timestamp without time zone NOT NULL,thread text,level text,logger text,message text,exception text,stack_trace_detail text,location text,identity text,app_domain text,user_name text,ndc text,utc_date timestamp without time zone,aspnet_cache text,aspnet_context text,aspnet_request text,aspnet_session text,CONSTRAINT log_pkey PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE log
  OWNER TO postgres;

-- Index: idx_log_level

-- DROP INDEX idx_log_level;

CREATE INDEX idx_log_level
  ON log
  USING btree
  (level COLLATE pg_catalog."default");

-- Index: uidx_log_date

-- DROP INDEX uidx_log_date;

CREATE UNIQUE INDEX uidx_log_date
  ON log
  USING btree
  (date);

发完贴子才发现系统将"给解析成了双引号，再直接贴上：

<!--如果想在Postgresql中保持字段字有大小写，要加入&quot 但是由于我用了Ormlite，所以不需要了 <commandText value="INSERT INTO &quot;Log&quot; (&quot;AppDomain&quot;,&quot;AspnetCache&quot;,&quot;AspnetContext&quot;,&quot;AspnetRequest&quot;,&quot;AspnetSession&quot;,&quot;Logger&quot;,&quot;Date&quot;,&quot;Identity&quot;,&quot;Level&quot;,&quot;Location&quot;,&quot;Exception&quot;,&quot;Message&quot;,&quot;Thread&quot;,&quot;NDC&quot;,&quot;StackTraceDetail&quot;,&quot;UserName&quot;,&quot;UTCDate&quot;) VALUES (:AppDomain,:UTCDate)"/> -->