如何从 Hibernate 和 Spring 获取数据库查询的打印输出

Question

I work on a huge Java project includes Spring and hibernate.

I was recently debugging some database query issues and drilled down until I discovered this is actually where a query is executed:

org.springframework.transaction.support.TransactionTemplate.execute(TransactionCallback<T>)

The code for the callback method it takes as the input argument is:

new TransactionCallback<List<?>>() {
    @Override
    public List<?> doInTransaction(TransactionStatus status) {
        String queryString = query.createHQLQuery();
        Query hibQuery = getCurrentSession().createQuery(queryString);
        try {
            query.populateHQLQuery(hibQuery, getSessionFactory());
        } catch (DataAccessLayerException e) {
            throw new org.hibernate.TransactionException("Error populating query", e);
        }
        // hibQuery.setCacheMode(CacheMode.NORMAL);
        // hibQuery.setCacheRegion(QUERY_CACHE_REGION);
        if (query.getMaxResults() != null) {
            hibQuery.setMaxResults(query.getMaxResults());
        }
        List<?> results = hibQuery.list();
        return results;
    }
}

I was able to get printouts of the query to the database to debug the problem, but it was messy. The best I could do was to call

org.hibernate.Query.getQueryString()

To get a template for a query, instead of the names of fields and values I got numbered substitution variables, ie " select param1, param2 from Yada where thisthing = param3".

I was able to call

org.hibernate.Query.getNamedParameters()

To get the values of the named parameters ( param1, param2, param3 ).

However, this was quite cumbersome as the queries were quite large and complicated.

What I would like to know if there is a way to get a query to print to standard out, that already has the substitution variables replaced with the values, the named parameters. Basically, a complete query as someone would manually type into a database.

Answer 1

In hibernate configuration

If you are using JPA in persistence.xml

<property name="hibernate.show_sql" value="true" />

If you want parameter values

Configure the Log4j in Hibernate

Modify the Log4j properties file, and change the log level to “debug” or “trace” in “log4j.logger.org.hibernate.type” property.

# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

# Root logger option
log4j.rootLogger=INFO, stdout

# Hibernate logging options (INFO only shows startup messages)
log4j.logger.org.hibernate=INFO

# Log JDBC bind parameter runtime arguments
log4j.logger.org.hibernate.type=trace

Answer 2

Add to application properties

 spring.jpa.properties.hibernate.show_sql=true
    spring.jpa.properties.hibernate.use_sql_comments=true
    spring.jpa.properties.hibernate.format_sql=true

To log values:

spring.jpa.properties.hibernate.type=trace 

Answer 3

If you want the statements written to your log, set the log level of org.hibernate.SQL to DEBUG . Bind parameters are logged if you set the log level of org.hibernate.type.descriptor.sql to TRACE .

As other answers suggest using hibernate.show_sql instructs Hibernate to write the SQL statements to STDOUT. As a consequence this cannot be controlled by the logging framework of your choice. Another major disadvantage is: the persistence.xml is usually part of your application's JAR and cannot be changed without repackaging your application.

Recommended reading: Hibernate Logging Guide – Use the right config for development and production