如何解决DbUnit的Maven插件在执行过程中出现的侵犯外键约束错误(MySQLIntegrityConstraintViolationException)

如果是在使用UbUnit进行单元测试时遇到

其实这个问题不止在通过DbUnit的Maven插件操作数据库时会遇到，在基于DbUni进行单元测试时也会遇到，一般的处理方法是在每次获取连接时前执行一个"set  @@session.foreign_key_checks = 0"的statement，以保证本次会话不作外键约束检查，以下是我常用的一个基于DbUnit的单元测试基类，其中第59行就是关于禁止外键约束检查的设置。（注：本例使用的数据库是MySql）

package oobbs.domainmodel;import java.sql.SQLException;import javax.sql.DataSource;import org.dbunit.DataSourceDatabaseTester;import org.dbunit.DefaultOperationListener;import org.dbunit.database.DatabaseConfig;import org.dbunit.database.IDatabaseConnection;import org.dbunit.dataset.xml.XmlDataSet;import org.dbunit.ext.mysql.MySqlDataTypeFactory;import org.junit.After;import org.junit.Before;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.core.io.ClassPathResource;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import org.springframework.transaction.annotation.Transactional;import testutil.ApplicationContextSupport;/** * This base class does not extends any DBTestCase of dbunit,or use any Tester,Their's implement is not good and flexible. * Here,we prepare and set connection manully! *  * @author Laurence Geng */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(locations = {"classpath:/applicationContext-infrastructure.xml",   "classpath:/applicationContext-domainModel.xml",   "classpath:/applicationContext-test.xml"})public abstract class DbBasedTest{    /** The data source. */    @Autowired    protected DataSource dataSource;    /** The dbunitTestUtil can fill test data from xml into test db before testing. */    protected DataSourceDatabaseTester dbunitTestUtil;        /**     * Inits dbunitTestUtil.  * The connectionRetrieved method is called back when setUp() executes. * At this time,we should set connection-specific setting: set foreign key check disabled * so as dbunit can invert test data, and set data type factory be MySqlDataTypeFactory so as * dbunit can convert correct type when invert data to mysql. *     * @throws Exception the exception     */    protected void initDbunitTestUtil() throws Exception{    dbunitTestUtil = new DataSourceDatabaseTester(dataSource);dbunitTestUtil.setDataSet(new XmlDataSet(new ClassPathResource("dbunit-test-data.xml").getInputStream()));dbunitTestUtil.setOperationListener( new DefaultOperationListener(){            public void connectionRetrieved(IDatabaseConnection connection) {                try {                //Disable foreign key check!connection.getConnection().prepareStatement("set @@session.foreign_key_checks = 0").execute();// When a new connection has been created then invoke the setUp method// so that user defined DatabaseConfig parameters can be set.connection.getConfig().setProperty(DatabaseConfig.PROPERTY_DATATYPE_FACTORY, new MySqlDataTypeFactory());} catch (SQLException e) {e.printStackTrace();}            }});    }/** * Before test method. *  * @throws Exception the exception */@Before    public void beforeTestMethod() throws Exception { initDbunitTestUtil();dbunitTestUtil.onSetup();    }        /**     * After test method.     *      * @throws Exception the exception     */    @After    public void afterTestMethod() throws Exception {    dbunitTestUtil.onTearDown();    }    }

如果是在使用DbUnit的Maven插件时遇到

而如果是使用Maven的DbUnit插件，以命令行的方式执行数据导入工作的话，就只能从数据库连接的url上下手了，方法也很简单就是在原插件的配置上添加foreign_key_checks = 0这个变量，以下是一个例子，请注意第14行<url>标记的部分：<url>${jdbc.url}&amp;sessionVariables=foreign_key_checks=0</url>，它在标准url后面追加了对变量foreign_key_checks的设置。

<plugin><groupId>org.codehaus.mojo</groupId><artifactId>dbunit-maven-plugin</artifactId><version>1.0-beta-3</version><dependencies><dependency><groupId>${jdbc.groupId}</groupId><artifactId>${jdbc.artifactId}</artifactId><version>${jdbc.version}</version></dependency></dependencies><configuration><driver>${jdbc.driverClassName}</driver><url>${jdbc.url}&sessionVariables=foreign_key_checks=0</url><username>${jdbc.username}</username><password>${jdbc.password}</password></configuration><executions><execution><id>default-cli</id><goals><goal>operation</goal></goals><configuration><type>CLEAN_INSERT</type><src>src/test/resources/dbunit-test-data.xml</src><dataTypeFactoryName>org.dbunit.ext.mysql.MySqlDataTypeFactory</dataTypeFactoryName><transaction>true</transaction></configuration></execution></executions></plugin>

备注：

mysql中，变量的作用域有两种session和global,改变变量值的方法为：

要想设置一个GLOBAL变量的值，使用下面的语法：

mysql> SET GLOBAL sort_buffer_size=value;
mysql> SET @@global.sort_buffer_size=value;

要想设置一个SESSION变量的值，使用下面的语法：

mysql> SET SESSION sort_buffer_size=value;
mysql> SET @@session.sort_buffer_size=value;
mysql> SET sort_buffer_size=value;