标签: mybatis

Mybatis的返回值

insert,返回值是:新插入行的主键(primary key);需要包含<selectKey>语句,才会返回主键,否则返回值为null。
update/delete,返回值是:更新或删除的行数;无需指明resultClass;但如果有约束异常而删除失败,只能去捕捉异常。
queryForObject,返回的是:一个实例对象或null;需要包含<select>语句,并且指明resultMap;
queryForList,返回的是:实例对象的列表;需要包含<select>语句,并且指明resultMap;

mybatis接口源码(com\ibatis\sqlmap\client\SqlMapExecutor.java):

[java]
/*
* Copyright 2004 Clinton Begin
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.ibatis.sqlmap.client;

import com.ibatis.common.util.PaginatedList;
import com.ibatis.sqlmap.client.event.RowHandler;
import com.ibatis.sqlmap.engine.execution.BatchException;

import java.sql.SQLException;
import java.util.List;
import java.util.Map;

/**
* This interface declares all methods involved with executing statements
* and batches for an SQL Map.
*
* @see SqlMapSession
* @see SqlMapClient
*/
public interface SqlMapExecutor {

/**
* Executes a mapped SQL INSERT statement.
* Insert is a bit different from other update methods, as it
* provides facilities for returning the primary key of the
* newly inserted row (rather than the effected rows). This
* functionality is of course optional.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the INSERT values.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @return The primary key of the newly inserted row. This might be automatically
* generated by the RDBMS, or selected from a sequence table or other source.
* @throws java.sql.SQLException If an error occurs.
*/
Object insert(String id, Object parameterObject) throws SQLException;

/**
* Executes a mapped SQL INSERT statement.
* Insert is a bit different from other update methods, as it
* provides facilities for returning the primary key of the
* newly inserted row (rather than the effected rows). This
* functionality is of course optional.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @return The primary key of the newly inserted row. This might be automatically
* generated by the RDBMS, or selected from a sequence table or other source.
* @throws java.sql.SQLException If an error occurs.
*/
Object insert(String id) throws SQLException;

/**
* Executes a mapped SQL UPDATE statement.
* Update can also be used for any other update statement type,
* such as inserts and deletes. Update returns the number of
* rows effected.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the UPDATE values as well as the WHERE clause parameter(s).
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @return The number of rows effected.
* @throws java.sql.SQLException If an error occurs.
*/
int update(String id, Object parameterObject) throws SQLException;

/**
* Executes a mapped SQL UPDATE statement.
* Update can also be used for any other update statement type,
* such as inserts and deletes. Update returns the number of
* rows effected.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @return The number of rows effected.
* @throws java.sql.SQLException If an error occurs.
*/
int update(String id) throws SQLException;

/**
* Executes a mapped SQL DELETE statement.
* Delete returns the number of rows effected.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the DELETE statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @return The number of rows effected.
* @throws java.sql.SQLException If an error occurs.
*/
int delete(String id, Object parameterObject) throws SQLException;

/**
* Executes a mapped SQL DELETE statement.
* Delete returns the number of rows effected.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @return The number of rows effected.
* @throws java.sql.SQLException If an error occurs.
*/
int delete(String id) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a single object instance.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @return The single result object populated with the result set data,
* or null if no result was found
* @throws java.sql.SQLException If more than one result was found, or if any other error occurs.
*/
Object queryForObject(String id, Object parameterObject) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a single object instance.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @return The single result object populated with the result set data,
* or null if no result was found
* @throws java.sql.SQLException If more than one result was found, or if any other error occurs.
*/
Object queryForObject(String id) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* the supplied result object.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param resultObject The result object instance that should be populated with result data.
* @return The single result object as supplied by the resultObject parameter, populated with the result set data,
* or null if no result was found
* @throws java.sql.SQLException If more than one result was found, or if any other error occurs.
*/
Object queryForObject(String id, Object parameterObject, Object resultObject) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @return A List of result objects.
* @throws java.sql.SQLException If an error occurs.
*/
List queryForList(String id, Object parameterObject) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @return A List of result objects.
* @throws java.sql.SQLException If an error occurs.
*/
List queryForList(String id) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects within a certain range.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param skip The number of results to ignore.
* @param max The maximum number of results to return.
* @return A List of result objects.
* @throws java.sql.SQLException If an error occurs.
*/
List queryForList(String id, Object parameterObject, int skip, int max) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects within a certain range.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @param skip The number of results to ignore.
* @param max The maximum number of results to return.
* @return A List of result objects.
* @throws java.sql.SQLException If an error occurs.
*/
List queryForList(String id, int skip, int max) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns a number of
* result objects that will be handled one at a time by a
* RowHandler.
*</pre>
&nbsp;
<pre> * This is generally a good approach to take when dealing with large sets
* of records (i.e. hundreds, thousands…) that need to be processed without
* eating up all of the system resources.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param rowHandler A RowHandler instance
* @throws java.sql.SQLException If an error occurs.
*/
void queryWithRowHandler(String id, Object parameterObject, RowHandler rowHandler) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns a number of
* result objects that will be handled one at a time by a
* RowHandler.
*</pre>
&nbsp;
<pre> * This is generally a good approach to take when dealing with large sets
* of records (i.e. hundreds, thousands…) that need to be processed without
* eating up all of the system resources.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @param rowHandler A RowHandler instance
* @throws java.sql.SQLException If an error occurs.
*/
void queryWithRowHandler(String id, RowHandler rowHandler) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects a page at a time.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param pageSize The maximum number of result objects each page can hold.
* @return A PaginatedList of result objects.
* @throws java.sql.SQLException If an error occurs.
* @deprecated All paginated list features have been deprecated
*/
PaginatedList queryForPaginatedList(String id, Object parameterObject, int pageSize) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects a page at a time.
*</pre>
&nbsp;
<pre> * This overload assumes no parameter is needed.
*
* @param id The name of the statement to execute.
* @param pageSize The maximum number of result objects each page can hold.
* @return A PaginatedList of result objects.
* @throws java.sql.SQLException If an error occurs.
* @deprecated All paginated list features have been deprecated
*/
PaginatedList queryForPaginatedList(String id, int pageSize) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects that will be keyed into a Map.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param keyProp The property to be used as the key in the Map.
* @return A Map keyed by keyProp with values being the result object instance.
* @throws java.sql.SQLException If an error occurs.
*/
Map queryForMap(String id, Object parameterObject, String keyProp) throws SQLException;

/**
* Executes a mapped SQL SELECT statement that returns data to populate
* a number of result objects from which one property will be keyed into a Map.
*</pre>
&nbsp;
<pre> * The parameter object is generally used to supply the input
* data for the WHERE clause parameter(s) of the SELECT statement.
*
* @param id The name of the statement to execute.
* @param parameterObject The parameter object (e.g. JavaBean, Map, XML etc.).
* @param keyProp The property to be used as the key in the Map.
* @param valueProp The property to be used as the value in the Map.
* @return A Map keyed by keyProp with values of valueProp.
* @throws java.sql.SQLException If an error occurs.
*/
Map queryForMap(String id, Object parameterObject, String keyProp, String valueProp) throws SQLException;

/**
* Starts a batch in which update statements will be cached before being sent to
* the database all at once. This can improve overall performance of updates update
* when dealing with numerous updates (e.g. inserting 1:M related data).
*
* @throws java.sql.SQLException If the batch could not be started.
*/
void startBatch() throws SQLException;

/**
* Executes (flushes) all statements currently batched.
*
* @return the number of rows updated in the batch
* @throws java.sql.SQLException If the batch could not be executed or if any of the statements
* fails.
*/
int executeBatch() throws SQLException;

/**
* Executes (flushes) all statements currently batched.
*
* @return a List of BatchResult objects. There will be one element in the
* list for each sub-batch executed. A sub-batch is created by adding a statement
* to the batch that does not equal the prior statement.
* @throws SQLException if a database access error occurs, or the drive
* does not support batch statements
* @throws BatchException if the driver throws BatchUpdateException
* @see com.ibatis.sqlmap.engine.execution.BatchException
*/
List executeBatchDetailed() throws SQLException, BatchException;
}
[/java]

mybatis报错invalid types () or values ()解决方法

报错信息:
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.reflection.ReflectionException: Error instantiating class com.huawei.PIM.DA.common.tools.DB.bean.table.T_contactList with invalid types () or values (). Cause: java.lang.NoSuchMethodException: com.huawei.PIM.DA.common.tools.DB.bean.table.T_contactList.<init>()

原因:
1) model中的get/set方法与成员变量不一。
2) 构造函数被重载过,但是没有空的构造函数。
3) 最好不要使用简单类型,如int, long等,改用对象模式Integer, Long等。在写条件查询时会用到判断<if xxx != null > … </if>的

Maven快速构建springmvc+mybatis项目

1. git clone https://github.com/chinageek/maven-archetype-templates.git

2. cd git/maven-archetype-templates/quickstart-springmvc-mybatis

3. mvn clean

4. mvn archetype:create-from-project

5. cd target/generated-sources/archetype

6. mvn clean install

7. mvn archetype:generate

8. Enjoy :-)