本章中分析update元素的解析。

1 配置文件

<update id="updateByPrimaryKeySelective" parameterType="cn.vansky.schedule.time.menu.bo.Menu"><!--WARNING - @mbggeneratedThis element is automatically generated by MyBatis Generator, do not modify.This element was generated on Fri Aug 14 16:08:36 CST 2015.-->update tb_menu<set><if test="menuName != null">menu_name = #{menuName,jdbcType=VARCHAR},</if><if test="menuRemark != null">menu_remark = #{menuRemark,jdbcType=VARCHAR},</if><if test="menuParentId != null">menu_parent_id = #{menuParentId,jdbcType=INTEGER},</if><if test="menuUrl != null">menu_url = #{menuUrl,jdbcType=VARCHAR},</if><if test="isShow != null">is_show = #{isShow,jdbcType=TINYINT},</if><if test="isDelete != null">is_delete = #{isDelete,jdbcType=TINYINT},</if><if test="operationUserName != null">operation_user_name = #{operationUserName,jdbcType=VARCHAR},</if><if test="operationTime != null">operation_time = #{operationTime,jdbcType=TIMESTAMP},</if></set>where Id = #{id,jdbcType=INTEGER}
</update>

2 方法parseStatementNode

public void parseStatementNode() {// updateByPrimaryKeySelectiveString id = context.getStringAttribute("id");// nullString databaseId = context.getStringAttribute("databaseId");// 第一次检查这里是不通过的，直接跳过if (!databaseIdMatchesCurrent(id, databaseId, this.requiredDatabaseId)) return;// null Integer fetchSize = context.getIntAttribute("fetchSize");// nullInteger timeout = context.getIntAttribute("timeout");// nullString parameterMap = context.getStringAttribute("parameterMap");// cn.vansky.schedule.time.menu.bo.MenuString parameterType = context.getStringAttribute("parameterType");// class cn.vansky.schedule.time.menu.bo.MenuClass<?> parameterTypeClass = resolveClass(parameterType);// nullString resultMap = context.getStringAttribute("resultMap");// nullString resultType = context.getStringAttribute("resultType");// nullString lang = context.getStringAttribute("lang");// 获取默认的处理对象// org.apache.ibatis.scripting.xmltags.XMLLanguageDriverLanguageDriver langDriver = getLanguageDriver(lang);// nullClass<?> resultTypeClass = resolveClass(resultType);// nullString resultSetType = context.getStringAttribute("resultSetType");// PREPAREDStatementType statementType = StatementType.valueOf(context.getStringAttribute("statementType", StatementType.PREPARED.toString()));// nullResultSetType resultSetTypeEnum = resolveResultSetType(resultSetType);// updateString nodeName = context.getNode().getNodeName();// UPDATESqlCommandType sqlCommandType = SqlCommandType.valueOf(nodeName.toUpperCase(Locale.ENGLISH));// falseboolean isSelect = sqlCommandType == SqlCommandType.SELECT;// trueboolean flushCache = context.getBooleanAttribute("flushCache", !isSelect);// falseboolean useCache = context.getBooleanAttribute("useCache", isSelect);// falseboolean resultOrdered = context.getBooleanAttribute("resultOrdered", false);// Include Fragments before parsingXMLIncludeTransformer includeParser = new XMLIncludeTransformer(configuration, builderAssistant);// 解析<include refid="Base_Column_List" />includeParser.applyIncludes(context.getNode());// Parse selectKey after includes and remove them.processSelectKeyNodes(id, parameterTypeClass, langDriver);// 这里很明显也是动态SQL// org.apache.ibatis.scripting.xmltags.DynamicSqlSourceSqlSource sqlSource = langDriver.createSqlSource(configuration, context, parameterTypeClass);// nullString resultSets = context.getStringAttribute("resultSets");// nullString keyProperty = context.getStringAttribute("keyProperty");// nullString keyColumn = context.getStringAttribute("keyColumn");// org.apache.ibatis.executor.keygen.NoKeyGeneratorKeyGenerator keyGenerator;// updateByPrimaryKeySelective!selectKeyString keyStatementId = id + SelectKeyGenerator.SELECT_KEY_SUFFIX;// cn.vansky.schedule.time.menu.dao.MenuMapper.updateByPrimaryKeySelective!selectKeykeyStatementId = builderAssistant.applyCurrentNamespace(keyStatementId, true);if (configuration.hasKeyGenerator(keyStatementId)) {keyGenerator = configuration.getKeyGenerator(keyStatementId);} else {keyGenerator = context.getBooleanAttribute("useGeneratedKeys",configuration.isUseGeneratedKeys() && SqlCommandType.INSERT.equals(sqlCommandType))? new Jdbc3KeyGenerator() : new NoKeyGenerator();}builderAssistant.addMappedStatement(id, sqlSource, statementType, sqlCommandType,fetchSize, timeout, parameterMap, parameterTypeClass, resultMap, resultTypeClass,resultSetTypeEnum, flushCache, useCache, resultOrdered, keyGenerator, keyProperty, keyColumn, databaseId, langDriver, resultSets);}

updateByPrimaryKeySelective最终的MappedStatement

下面就来看动态SqlSource的属性。