Tracking SQL statements with log4j in MYBATIS3

Printing SQL statements should be a useful feature during development.

The following describes how to turn on the ability to print SQL statements in Mybatis3.

MyBatis the built-in log factory provides logging capabilities, specific log implementations are available in the following ways:

• Slf4j

• Apache Commons Logging

• Log4j 2

• Log4j

• JDK Logging

Select which log implementation is determined by MyBatis's built-in log factory. It will use the first found (find in the order listed above). If none is found, the log function is disabled

In addition MyBatis official online said many environments ship Commons Logging as a part of the application Server Classpath (good examples include T Omcat and WebSphere).

But in fact, Tomcat classpath under not commons-logging package, in fact, even if the project used to, it can also combine log4j good work.

So, let's get started!

1, import log4j package, here is the log4j-1.2.17

2, configuration log4j.properties (file placed under Classpath)

The following configuration will output all SQL statements

Log4j.rootlogger=error, consolelog4j.logger.com.zhuchao.test.dao=debug#consolelog4j.appender.console= org.apache.log4j.consoleappenderlog4j.appender.console.layout= org.apache.log4j.patternlayoutlog4j.appender.console.layout.conversionpattern=%d [%t]%-5p [%c]-%m%n

Where Com.zhuchao.test.dao is the package name where the Mapper class is located, if you want to specify a mapper output SQL statement

You can also implement finer-grained configurations, such as Log4j.logger.com.zhuchao.test.dao.personmapper=debug

A little bit more, you can also specify a specific SQL statement, such as Log4j.logger.com.zhuchao.test.dao.personmapper.selectbyid=debug

If you want to log records of mapper.xml files, you just need to namespace.

The Mapper.xml and Mapper classes in the general project are one by one corresponding, so both configurations are the same.

It is worth noting that the debug log level only prints SQL statements, parameters, and the number of records affected

2014-09-14 00:49:10,078 [http-8080-3] DEBUG [com.zhuchao.test.BasecodeMapper.selectByExample]-==>  Preparing : SELECT * from Basecode WHERE (cls =?) 2014-09-14 00:49:10,078 [http-8080-3] DEBUG [com.zhuchao.test.BasecodeMapper.se Lectbyexample]-==> parameters:level (String) 2014-09-14 00:49:10,079 [http-8080-3] DEBUG [ Com.zhuchao.test.BasecodeMapper.selectByExample]-<==      total:2

If you also want to see all the execution results, you can set the log level to trace:

2014-09-14 00:49:10,078 [http-8080-3] DEBUG [com.zhuchao.test.BasecodeMapper.selectByExample]-==>  Preparing : SELECT * from Basecode WHERE (cls =?) 2014-09-14 00:49:10,078 [http-8080-3] DEBUG [com.zhuchao.test.BasecodeMapper.se Lectbyexample]-==> parameters:level (String) 2014-09-14 00:49:10,079 [http-8080-3] TRACE [ Com.zhuchao.test.BasecodeMapper.selectByExample]-<==    columns:cls, ID, code, name, description, seq2014-09-14 00:49:10,079 [http-8080-3] TRACE [com.zhuchao.test.BasecodeMapper.selectByExample]-<==        row:level, 1, Level2, Level 2, Level 2, 02014-09-14 00:49:10,079 [http-8080-3] TRACE [com.zhuchao.test.BasecodeMapper.selectByExample]-<==        Row:level, 2, Level1, Level 1, Level 1, 02014-09-14 00:49:10,079 [http-8080-3] DEBUG [ Com.zhuchao.test.BasecodeMapper.selectByExample]-<==      total:2

Tracking SQL statements with log4j in MYBATIS3