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本章中分析insert元素的解析。

1 配置文件

<insert?id="insert"?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.-->insert?into?tb_menu?(menu_name,?menu_remark,?menu_parent_id,?menu_url,?is_show,?is_delete,?operation_user_name,?operation_time)values?(#{menuName,jdbcType=VARCHAR},?#{menuRemark,jdbcType=VARCHAR},?#{menuParentId,jdbcType=INTEGER},?#{menuUrl,jdbcType=VARCHAR},?#{isShow,jdbcType=TINYINT},?#{isDelete,jdbcType=TINYINT},?#{operationUserName,jdbcType=VARCHAR},?#{operationTime,jdbcType=TIMESTAMP}) </insert>

2 方法buildStatementFromContext

private?void?buildStatementFromContext(List<XNode>?list)?{if?(configuration.getDatabaseId()?!=?null)?{buildStatementFromContext(list,?configuration.getDatabaseId());}buildStatementFromContext(list,?null);}private?void?buildStatementFromContext(List<XNode>?list,?String?requiredDatabaseId)?{for?(XNode?context?:?list)?{//?對一個SQL進行解析final?XMLStatementBuilder?statementParser?=?new?XMLStatementBuilder(configuration,?builderAssistant,?context,?requiredDatabaseId);try?{statementParser.parseStatementNode();}?catch?(IncompleteElementException?e)?{configuration.addIncompleteStatement(statementParser);}} }

上面是一個總的方法包括，insert、update、delete、select4中元素都會進入此方法。這里也會捕獲一種異常，并把錯誤的解析放入Configuration(全局配置類)的Collection<XMLStatementBuilder> incompleteStatements = new LinkedList<XMLStatementBuilder>()。

3 方法parseStatementNode

public?void?parseStatementNode()?{//?insertString?id?=?context.getStringAttribute("id");//?nullString?databaseId?=?context.getStringAttribute("databaseId");//?第一次檢查這里是不通過的，直接跳過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");//?獲取默認的處理對象//?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);//?insertString?nodeName?=?context.getNode().getNodeName();//?INSERTSqlCommandType?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);//?這里通過下面分析獲取的SQL源（靜態SQL源），因為沒有動態標簽SqlSource?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;//?insert!selectKeyString?keyStatementId?=?id?+?SelectKeyGenerator.SELECT_KEY_SUFFIX;//?cn.vansky.schedule.time.menu.dao.MenuMapper.insert!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);}

4?方法XMLLanguageDriver.createSqlSource

public?SqlSource?createSqlSource(Configuration?configuration,?XNode?script,?Class<?>?parameterType)?{XMLScriptBuilder?builder?=?new?XMLScriptBuilder(configuration,?script,?parameterType);//?入參Class及節點解析return?builder.parseScriptNode(); }

5 方法XMLScriptBuilder.parseScriptNode

public?SqlSource?parseScriptNode()?{//?解析動態標簽，if、where、forList<SqlNode>?contents?=?parseDynamicTags(context);//?所有動態標簽集合類MixedSqlNode?rootSqlNode?=?new?MixedSqlNode(contents);SqlSource?sqlSource?=?null;if?(isDynamic)?{sqlSource?=?new?DynamicSqlSource(configuration,?rootSqlNode);}?else?{sqlSource?=?new?RawSqlSource(configuration,?rootSqlNode,?parameterType);}return?sqlSource; }

6 方法XMLScriptBuilder.parseDynamicTags

private?List<SqlNode>?parseDynamicTags(XNode?node)?{List<SqlNode>?contents?=?new?ArrayList<SqlNode>();//?獲取動態標簽與內容列表NodeList?children?=?node.getNode().getChildNodes();for?(int?i?=?0;?i?<?children.getLength();?i++)?{XNode?child?=?node.newXNode(children.item(i));//?內容if?(child.getNode().getNodeType()?==?Node.CDATA_SECTION_NODE?||?child.getNode().getNodeType()?==?Node.TEXT_NODE)?{String?data?=?child.getStringBody("");//?內容SqlNodeTextSqlNode?textSqlNode?=?new?TextSqlNode(data);//?動態修改的內容if?(textSqlNode.isDynamic())?{contents.add(textSqlNode);isDynamic?=?true;}?else?{//?靜態內容contents.add(new?StaticTextSqlNode(data));}}?else?if?(child.getNode().getNodeType()?==?Node.ELEMENT_NODE)?{?//?issue?#628//?節點為元素，也就是動態標簽where、if、forString?nodeName?=?child.getNode().getNodeName();//?獲取動態標簽處理器WhereHandler、ForEachHandlerNodeHandler?handler?=?nodeHandlers.get(nodeName);if?(handler?==?null)?{throw?new?BuilderException("Unknown?element?<"?+?nodeName?+?">?in?SQL?statement.");}//?處理器處理內容，并把處理的內容加入到SQLNodehandler.handleNode(child,?contents);isDynamic?=?true;}}return?contents;}

方法5中有2中數據源DynamicSqlSource(動態SQL源)和RawSqlSource(靜態SQL源)，動態SQL源就是包括where、if、for，靜態SQL源就是只包括SQL語句，下面就簡單分析一下2中SQL源。

7?RawSqlSource(靜態SQL源)

public?RawSqlSource(Configuration?configuration,?String?sql,?Class<?>?parameterType)?{SqlSourceBuilder?sqlSourceParser?=?new?SqlSourceBuilder(configuration);Class<?>?clazz?=?parameterType?==?null???Object.class?:?parameterType;sqlSource?=?sqlSourceParser.parse(sql,?clazz,?new?HashMap<String,?Object>()); } public?SqlSource?parse(String?originalSql,?Class<?>?parameterType,?Map<String,?Object>?additionalParameters)?{//?參數處理MappingParameterMappingTokenHandler?handler?=?new?ParameterMappingTokenHandler(configuration,?parameterType,?additionalParameters);GenericTokenParser?parser?=?new?GenericTokenParser("#{",?"}",?handler);//?解析XML中的SQL語句，#{menuName,jdbcType=VARCHAR}，轉換成？及對應的處理類型ParameterMappingString?sql?=?parser.parse(originalSql);return?new?StaticSqlSource(configuration,?sql,?handler.getParameterMappings()); }

這里直接解析并生成StaticSqlSource，包括SQL語句及對應的處理類型。

7.1 ParameterMapping對應的menuName

/**?全局配置類?*/ private?Configuration?configuration; /**?menuName?*/ private?String?property; /**?IN:輸入?*/ private?ParameterMode?mode; /**?class?java.lang.String?*/ private?Class<?>?javaType?=?Object.class; /**?VARCHAR?*/ private?JdbcType?jdbcType; /**?null?*/ private?Integer?numericScale; /**?StringTypeHandler?*/ private?TypeHandler<?>?typeHandler; /**?null?*/ private?String?resultMapId; /**?null?*/ private?String?jdbcTypeName; /**?null?*/ private?String?expression;

8?DynamicSqlSource(動態SQL源)

public?DynamicSqlSource(Configuration?configuration,?SqlNode?rootSqlNode)?{this.configuration?=?configuration;this.rootSqlNode?=?rootSqlNode; }

很明顯這里沒有進行生成SQL，那就是在具體獲取SQL時進行生成SQL

9 方法addMappedStatement

此方法只是賦值，沒有什么特殊處理，所以此方法不在分析，可以自行研究。

總結?

附上圖片MappedStatement屬性值

下面給出動態SQL源的MappedStatement屬性值

<insert?id="insertSelective"?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.-->insert?into?tb_menu<trim?prefix="("?suffix=")"?suffixOverrides=","><if?test="menuName?!=?null">menu_name,</if><if?test="menuRemark?!=?null">menu_remark,</if><if?test="menuParentId?!=?null">menu_parent_id,</if><if?test="menuUrl?!=?null">menu_url,</if><if?test="isShow?!=?null">is_show,</if><if?test="isDelete?!=?null">is_delete,</if><if?test="operationUserName?!=?null">operation_user_name,</if><if?test="operationTime?!=?null">operation_time,</if></trim><trim?prefix="values?("?suffix=")"?suffixOverrides=","><if?test="menuName?!=?null">#{menuName,jdbcType=VARCHAR},</if><if?test="menuRemark?!=?null">#{menuRemark,jdbcType=VARCHAR},</if><if?test="menuParentId?!=?null">#{menuParentId,jdbcType=INTEGER},</if><if?test="menuUrl?!=?null">#{menuUrl,jdbcType=VARCHAR},</if><if?test="isShow?!=?null">#{isShow,jdbcType=TINYINT},</if><if?test="isDelete?!=?null">#{isDelete,jdbcType=TINYINT},</if><if?test="operationUserName?!=?null">#{operationUserName,jdbcType=VARCHAR},</if><if?test="operationTime?!=?null">#{operationTime,jdbcType=TIMESTAMP},</if></trim> </insert>

其實這里屬性都差不多，主要是SqlSource不一樣，那么下來就看它的屬性。

轉載于:https://my.oschina.net/u/1269959/blog/523651

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