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2018-07-05
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摘要：本文主要向大家介绍了MFC编程实例：从零实现MVC框架之增删改查（4），通过具体的内容向大家展示，希望对大家学习MFC编程实例有所帮助。
本文主要向大家介绍了MFC编程实例：从零实现MVC框架之增删改查（4），通过具体的内容向大家展示，希望对大家学习MFC编程实例有所帮助。
概述
这一章节貌似有点小复杂。为了实现对象的增删改查，我们需要做点功课
1：生成id，我们采用手动生成id的方法，这里我们特意也为id创建了一个池子，所有的id都从池子里面取。
2：对象状态： 新建状态、持久状态、查询状态。查询状态是内部处理。
处于新建状态下的对象可以进行保存操作，不能更新和删除
处于持久状态下的对象可以进行更新和删除操作，不能保存。
3：执行器：我们所有的sql的执行都要靠执行器执行并返回结构。
4：数据装配：处理sql中的占位符以及返回结果的处理。
5：事务：提交和回滚。我们这里只是提供了这个方法，但是还没有具体实现。因为我们现在的连接都是自动提交的不涉及到事务问题。等到后面章节我们做AOP事务管理的时候会具体实现。
实现思路
为了简单起见，我们把增删改查方法都定义到实体类上。通过继承AbstractEntity可以继承这些方法。不过具体实体类不用实现这些方法。每个实体类在进行每次增删该查方法时，都会重新获取一个执行器，然后通过执行器执行sql。执行器也在AbstractEntity中创建。下面看具体代码：
实体类：
接口
[java] view plain copy
1. package com.hc.core;
2.
3. import java.sql.SQLException;
4.
5. /**
6. * 实体接口 所有数据库实体都必须实现这个接口
7. * @author chuer
8. * @date 2014-7-16 下午12:07:47
9. * @version V1.0
10. */
11. public interface IEntity {
12.
13. public long getId();//获得实体主键
14.
15. public void setId(long id);//设置实体主键
16.
17. public void persist() throws SQLException;//增
18.
19. public void remove() throws SQLException;//删
20.
21. public IEntity get(long id) throws SQLException;//查
22.
23. public void update(String columnName) throws SQLException;//改
24.
25. public void setExecute();//设置执行器
26.
27.
28. public void rollBack();
29.
30.
31.
32.
33. }
抽象实现
[java] view plain copy
1. package com.hc.core;
2.
3. import java.sql.SQLException;
4.
5. /**
6. * 抽象实体类
7. * @author chuer
8. * @date 2014-7-16 下午12:08:42
9. * @version V1.0
10. */
11. public abstract class AbstractEntity implements IEntity {
12.
13. protected AbstractExecute<AbstractEntity> execute;
14. protected EntityStatus status;
15.
16. public AbstractEntity(){
17. this.status = EntityStatus.NEW;//状态为新建
18. }
19.
20. @Override
21. public void persist() throws SQLException {
22. //持久化对象 只有新建的对象才可以进行持久化
23. if(this.status == EntityStatus.NEW){
24. setExecute();
25. try{
26. execute.save(this);
27. }catch(SQLException e){
28. rollBack();
29. throw e;
30. }
31. this.status = EntityStatus.PERSIST;
32. }
33. }
34.
35.
36. @Override
37. public void remove() throws SQLException{
38. //删除用户 只有持久化的对象才可以进行删除操作
39. if(this.status == EntityStatus.PERSIST){
40. setExecute();
41. try {
42. execute.delete(this);
43. } catch (SQLException e) {
44. rollBack();
45. throw e;
46. }
47. this.status = EntityStatus.NEW;
48. }
49. }
50.
51. @Override
52. public AbstractEntity get(long id) throws SQLException {
53. this.setId(id);
54. this.status = EntityStatus.QUERY;
55. setExecute();
56. execute.get(this);
57. this.status = EntityStatus.PERSIST;
58. return this;
59. }
60.
61. @Override
62. public void update(String columnName) throws SQLException{
63. //只有持久化对象才能进行更新操作
64. if(this.status == EntityStatus.PERSIST){
65. setExecute();
66. try{
67. execute.update(this, columnName);
68. }catch(SQLException e){
69. rollBack();
70. throw e;
71. }
72. }
73. }
74.
75. public EntityStatus getStatus() {
76. return status;
77. }
78.
79. public void setStatus(EntityStatus status) {
80. this.status = status;
81. }
82.
83. @Override
84. public void setExecute() {
85. execute = ExecuteFactory.getExecute();
86. }
87.
88. @Override
89. public void rollBack() {
90. }
91.
92.
93.
94.
95.
96. }
具体实现
[java] view plain copy
1. package com.hc.sample.entity;
2.
3. import java.sql.SQLException;
4.
5. import com.hc.annotation.Column;
6. import com.hc.annotation.Entity;
7. import com.hc.core.AbstractEntity;
8. /**
9. *
10. * @author chuer
11. * @date 2014-7-16 上午9:33:02
12. * @version V1.0
13. */
14. @Entity(entityName="UserEntity",tableName="user_m")
15. public class UserEntity extends AbstractEntity{
16.
17. public UserEntity(){
18. super();
19. }
20.
21. @Column(type=long.class,name="id",isPrimary=true)
22. private long id;
23.
24. @Column(type=String.class,name="name")
25. private String name;
26.
27.
28. public long getId() {
29. return id;
30. }
31.
32. public void setId(long id) {
33. this.id = id;
34. }
35.
36. public String getName() {
37. return name;
38. }
39.
40.
41. public void setName(String name) throws SQLException {
42. this.name = name;
43. //更新数据到数据库 只有持久化的数据才可以更新操作
44. update("name");
45. }
46.
47.
48. }
ID生成
生成器
[java] view plain copy
1. package com.hc.utils;
2.
3. import java.util.Date;
4. /**
5. * id生成
6. * @author chuer
7. * @version 2014-7-16 上午11:38:34
8. */
9. public class UID {
10. private static Date date = new Date();
11. private static StringBuilder buf = new StringBuilder();
12. private static int seq = 0;
13. private static final int ROTATION = 99999;
14.
15. public static synchronized long next() {
16. if (seq > ROTATION)
17. seq = 0;
18. buf.delete(0, buf.length());
19. date.setTime(System.currentTimeMillis());
20. String str = String.format("%1$tY%1$tm%1$td%1$tk%1$tM%1$tS%2$05d",
21. date, seq++);
22. return Long.parseLong(str);
23. }
24.
25.
26. public static void main(String ...args){
27. new MyThread().start();
28. new MyThread().start();
29. new MyThread().start();
30. new MyThread().start();
31. new MyThread().start();
32. new MyThread().start();
33. new MyThread().start();
34. new MyThread().start();
35. new MyThread().start();
36. new MyThread().start();
37. }
38. }
39.
40. class MyThread extends Thread{
41.
42. @Override
43. public void run() {
44. for(int i=0;i<100;i++){
45. System.out.println(UID.next());
46. }
47. }
48. }
ID池
[java] view plain copy
1. package com.hc.pool;
2.
3. import java.util.concurrent.ConcurrentLinkedQueue;
4.
5. import com.hc.utils.UID;
6. /**
7. * id池子
8. * @author chuer
9. * @version 2014-7-16 下午12:23:26
10. */
11. public class IDPool {
12.
13. private static final int MAX_POOL_SIZE = 100000;//id池大小
14. private static final int MIN_POOL_SIZE = 100;//id池大小
15. private static volatile boolean isInit = false;
16. private IDPool(){}
17. private static IDPool pool = new IDPool();
18. private ConcurrentLinkedQueue<Long> pools = new ConcurrentLinkedQueue<Long>();
19.
20. public static IDPool getInstance(){
21. if(!isInit){
22. isInit = true;
23. pool.startGenerateId();
24. }
25. return pool;
26. }
27.
28. public void startGenerateId(){
29. GenerateId gi = new GenerateId();
30. new Thread(gi).start();
31. }
32.
33.
34. void addId(Long id){
35. pools.add(id);
36. }
37.
38. public Long applyId(){
39. Long id = pools.poll();
40. if(id == null){
41. return UID.next();
42. }
43. return id;
44. }
45.
46. class GenerateId implements Runnable{
47.
48. @Override
49. public void run() {
50. while(true){
51. if(pools.size()<MIN_POOL_SIZE){
52. while(true){
53. addId(UID.next());
54. if(pools.size() == MAX_POOL_SIZE){
55. break;
56. }
57. }
58. }
59.
60. try {
61. Thread.sleep(2000);
62. } catch (InterruptedException e) {
63. e.printStackTrace();
64. }
65. }
66.
67. }
68.
69. }
70. }
执行器
接口
[java] view plain copy
1. package com.hc.core;
2.
3. import java.sql.Connection;
4. import java.sql.SQLException;
5. import java.util.Collection;
6. /**
7. * 增删改差接口 执行器
8. * @author chuer
9. * @date 2014-7-16 上午10:08:17
10. * @version V1.0
11. */
12. public interface IExecute<T> {
13.
14. public int save(T t) throws SQLException; //保存操作
15.
16. public int update(T t, String column) throws SQLException; //更新操作
17.
18. public int delete(T t) throws SQLException; //删除操作
19.
20. public T get(T t) throws SQLException; //单个查询操作
21.
22. public Collection<T> query(Class<T> cls,String sql)throws SQLException;//批量查询操作
23.
24. public void execute(String sql) throws SQLException;//执行自定义sql
25.
26. public void relase(Connection conn);//释放连接
27.
28. public void setAutoCommit(boolean autoCommit);//设置连接是否自动提交
29. }
[java] view plain copy
1. package com.hc.core;
2. /**
3. * 事务提交接口
4. * @author chuer
5. * @version 2014-7-16 上午11:27:24
6. */
7. public interface ICommit {
8.
9. public void commit();//提交
10. public void rollback();//回滚
11.
12. }
抽象实现
[java] view plain copy
1. package com.hc.core;
2.
3. import java.sql.Connection;
4. import java.sql.SQLException;
5. import java.sql.Statement;
6.
7. import com.hc.pool.DBConfig;
8. import com.hc.pool.DBPool;
9.
10. /**
11. * 抽象执行器
12. * @author chuer
13. * @date 2014-7-16 上午10:08:51
14. * @version V1.0
15. */
16. public abstract class AbstractExecute<T> implements IExecute<T>,ICommit{
17.
18. protected Connection conn;
19. protected boolean autoCommit;
20.
21. protected AbstractExecute(Connection conn){
22. this.conn = conn;
23. this.autoCommit = DBConfig.AUTOCOMMIT;
24. }
25.
26. @Override
27. public void commit() {
28. try {
29. conn.commit();
30. relase(conn);
31. } catch (SQLException e) {
32. e.printStackTrace();
33. }
34. }
35.
36. @Override
37. public void rollback() {
38. try {
39. conn.rollback();
40. } catch (SQLException e) {
41. e.printStackTrace();
42. }
43. }
44.
45. @Override
46. public void relase(Connection conn) {
47. DBPool.getInstance().relaseConnection(conn);
48. }
49.
50. @Override
51. public void execute(String sql) throws SQLException {
52. System.out.println(sql);
53. Statement stat = conn.createStatement();
54. stat.execute(sql);
55. if(autoCommit){
56. commit();
57. }
58. }
59.
60. @Override
61. public void setAutoCommit(boolean autoCommit1) {
62. autoCommit = autoCommit1;
63. }
64.
65.
66.
67.
68.
69.
70. }
具体实现
[java] view plain copy
1. package com.hc.execute;
2.
3. import java.sql.Connection;
4. import java.sql.PreparedStatement;
5. import java.sql.ResultSet;
6. import java.sql.SQLException;
7. import java.sql.Statement;
8. import java.util.ArrayList;
9. import java.util.Collection;
10.
11. import com.hc.cache.CacheManager;
12. import com.hc.core.AbstractExecute;
13. import com.hc.core.IEntity;
14. import com.hc.sql.SqlManager;
15. import com.hc.utils.AssembleData;
16. import com.hc.utils.AssembleStatement;
17. /**
18. * 执行器实现类
19. * @author chuer
20. * @version 2014-7-16 上午11:36:08
21. * @param <T>
22. */
23. public class ExecuteImpl<T extends IEntity> extends AbstractExecute<T>{
24.
25. public ExecuteImpl(Connection conn){
26. super(conn);
27. }
28.
29. @Override
30. public int save(T t) throws SQLException {
31. String insertSql = SqlManager.getInstance().getInsertSql(t.getClass());
32. System.out.println(insertSql);
33. PreparedStatement stat = AssembleStatement.assembleInsertSql(t, insertSql, conn);
34. stat.execute();
35. if(autoCommit){
36. commit();
37. }
38. CacheManager.cache(t);
39. return 0;
40. }
41.
42. @Override
43. public int update(T t,String column) throws SQLException {
44. String updateSql = SqlManager.getInstance().getUpdateSql(t.getClass(),column);
45. System.out.println(updateSql);
46. PreparedStatement stat = AssembleStatement.assembleUpdateSql(t, updateSql, conn, column);
47. stat.execute();
48. if(autoCommit){
49. commit();
50. }
51. return 0;
52. }
53.
54. @Override
55. public int delete(T t) throws SQLException {
56. String deleteSql = SqlManager.getInstance().getDeleteSql(t.getClass());
57. System.out.println(deleteSql);
58. PreparedStatement stat = AssembleStatement.assembleDeleteSql(t, deleteSql, conn);
59. stat.execute();
60. if(autoCommit){
61. commit();
62. }
63. return 0;
64. }
65.
66. @Override
67. public T get(T t) throws SQLException {
68. String singleSql = SqlManager.getInstance().getSingleSql(t.getClass());
69. System.out.println(singleSql);
70. PreparedStatement stat = AssembleStatement.assembleSingleSql(t, singleSql, conn);
71. ResultSet rs = stat.executeQuery();
72. try {
73. AssembleData.assembleSingle(t, rs);
74. } catch (Exception e) {
75. e.printStackTrace();
76. }
77. if(autoCommit){
78. commit();
79. }
80. return t;
81. }
82.
83. @Override
84. public Collection<T> query(Class<T> cls,String condition)throws SQLException {
85. String querySql = SqlManager.getInstance().getQuerySql(cls);
86. querySql += condition;
87. System.out.println(querySql);
88. Statement stat = conn.createStatement();
89. ResultSet rs = stat.executeQuery(querySql);
90. Collection<T> list = null;
91. try {
92. list = AssembleData.assembleCollection(new ArrayList<T>(), cls, rs);
93. } catch (Exception e) {
94. e.printStackTrace();
95. }
96. if(autoCommit){
97. commit();
98. }
99. return list;
100. }
101.
102.
103.
104.
105.
106.
107. }
装配器：
[java] view plain copy
1. package com.hc.utils;
2.
3. import java.lang.reflect.Field;
4. import java.lang.reflect.Method;
5. import java.sql.Connection;
6. import java.sql.PreparedStatement;
7. import java.sql.SQLException;
8.
9. import com.hc.annotation.Column;
10. /**
11. * sql装配
12. * @author chuer
13. * @version 2014-7-16 上午10:13:05
14. */
15. public class AssembleStatement {
16.
17.
18. /**
19. * 装配单个查询sql
20. * @param t
21. * @param sql
22. * @param conn
23. * @return
24. */
25. public static <T> PreparedStatement assembleSingleSql(T t,String sql,Connection conn){
26. try{
27. PreparedStatement pStat= conn.prepareStatement(sql);
28. Field[] fields = t.getClass().getDeclaredFields();
29. for(Field fie : fields){
30. if(fie.isAnnotationPresent(Column.class)){
31. Column annotation = fie.getAnnotation(Column.class);
32. if(annotation.isPrimary()){
33. Object id = getColumnValue(fie.getName(), t);
34. fill(annotation,pStat,1,id);
35. break;
36. }
37. }
38. }
39. return pStat;
40. }catch(Exception e){
41. e.printStackTrace();
42. }
43. return null;
44. }
45. /**
46. * 装配删除sql
47. * @param t
48. * @param sql
49. * @param conn
50. * @return
51. */
52. public static <T> PreparedStatement assembleDeleteSql(T t,String sql,Connection conn){
53. try{
54. PreparedStatement pStat= conn.prepareStatement(sql);
55. Field[] fields = t.getClass().getDeclaredFields();
56. for(Field fie : fields){
57. if(fie.isAnnotationPresent(Column.class)){
58. Column annotation = fie.getAnnotation(Column.class);
59. if(annotation.isPrimary()){
60. Object id = getColumnValue(fie.getName(), t);
61. fill(annotation,pStat,1,id);
62. break;
63. }
64. }
65. }
66. return pStat;
67. }catch(Exception e){
68. e.printStackTrace();
69. }
70. return null;
71. }
72. /**
73. * 装配更新sql
74. * @param t
75. * @param sql
76. * @param conn
77. * @param columnName
78. * @return
79. */
80. public static <T> PreparedStatement assembleUpdateSql(T t,String sql,Connection conn,String columnName){
81. try{
82. PreparedStatement pStat= conn.prepareStatement(sql);
83. Object value = getColumnValue(columnName, t);
84. Field field = t.getClass().getDeclaredField(columnName);
85. fill(field.getAnnotation(Column.class),pStat,1,value);
86.
87.
88. Field[] fields = t.getClass().getDeclaredFields();
89. for(Field fie : fields){
90. if(fie.isAnnotationPresent(Column.class)){
91. Column annotation = fie.getAnnotation(Column.class);
92. if(annotation.isPrimary()){
93. Object id = getColumnValue(fie.getName(), t);
94. fill(annotation,pStat,2,id);
95. break;
96. }
97. }
98. }
99. return pStat;
100. }catch(Exception e){
101. e.printStackTrace();
102. }
103. return null;
104. }
105.
106. /**
107. * 装配插入sql
108. * @param t
109. * @param sql
110. * @param conn
111. * @return
112. * @throws SQLException
113. */
114. public static <T> PreparedStatement assembleInsertSql(T t,String sql,Connection conn)throws SQLException{
115. try{
116. PreparedStatement pStat= conn.prepareStatement(sql);
117. Field [] fileds = t.getClass().getDeclaredFields();
118. for(int i=0;i<fileds.length;i++){
119. Field field = fileds[i];
120. if(field.isAnnotationPresent(Column.class)){
121. Object value = getColumnValue(field.getName(),t);
122. fill(field.getAnnotation(Column.class),pStat,i+1,value);
123. }
124. }
125. return pStat;
126. }catch(Exception e){
127. e.printStackTrace();
128. }
129. return null;
130. }
131.
132. /**
133. * 得到字段的值
134. * @param columnName
135. * @param t
136. * @return
137. * @throws Exception
138. */
139. private static <T> Object getColumnValue(String columnName,T t)throws Exception{
140. String methodName = "get"+columnName.substring(0,1).toUpperCase()+columnName.substring(1, columnName.length());
141. Method method = t.getClass().getMethod(methodName, new Class[]{});
142. Object value = method.invoke(t, new Object[]{});
143. return value;
144. }
145. /**
146. * 替换sql中的？
147. * @param ctype
148. * @param pStat
149. * @param index
150. * @param value
151. * @throws Exception
152. */
153. private static void fill(Column ctype,PreparedStatement pStat,int index,Object value)throws Exception{
154. Class<? extends Object> type = ctype.type();
155. if(type == int.class){
156. pStat.setInt(index, (int)value);
157. }else if(type == byte.class){
158. pStat.setByte(index, (byte)value);
159. }else if(type == short.class){
160. pStat.setShort(index, (short)value);
161. }else if(type == long.class){
162. pStat.setLong(index, (long)value);
163. }else if(type == String.class){
164. pStat.setString(index, (String)value);
165. }
166. }
167. }
[java] view plain copy
1. package com.hc.utils;
2.
3. import java.lang.reflect.Field;
4. import java.lang.reflect.Method;
5. import java.sql.ResultSet;
6. import java.util.Collection;
7.
8. import com.hc.annotation.Column;
9. import com.hc.core.EntityStatus;
10.
11. public class AssembleData {
12.
13. /**
14. * 返回集合
15. * @param list
16. * @param cls
17. * @param rs
18. * @return
19. * @throws Exception
20. */
21. public static <T> Collection<T> assembleCollection(Collection<T> list,Class<T> cls,ResultSet rs)throws Exception{
22. while(rs.next()){
23. T instance = cls.getConstructor(new Class[]{}).newInstance(new Object[]{});
24. assemble(instance,rs);
25. list.add(instance);
26. }
27. return list;
28. }
29.
30. private static <T> T assemble(T t,ResultSet rs) throws Exception{
31. Method method = t.getClass().getMethod("setStatus", new Class[]{EntityStatus.class});
32. method.invoke(t, new Object[]{EntityStatus.QUERY});
33. Field[] declaredFields = t.getClass().getDeclaredFields();
34. for(Field field : declaredFields){
35. if(field.isAnnotationPresent(Column.class)){
36. Column annotation = field.getAnnotation(Column.class);
37.
38. String fieldName = field.getName();
39. String ColumnName = annotation.name();
40. Class<?> type = annotation.type();
41. setValue(t,type,rs,ColumnName,fieldName);
42. }
43. }
44. method.invoke(t, new Object[]{EntityStatus.PERSIST});
45. return t;
46. }
47. /**
48. * 返回单对象
49. * @param t
50. * @param rs
51. * @return
52. * @throws Exception
53. */
54. public static <T> T assembleSingle(T t,ResultSet rs) throws Exception{
55. if(rs.next()){
56. Field[] declaredFields = t.getClass().getDeclaredFields();
57. for(Field field : declaredFields){
58. if(field.isAnnotationPresent(Column.class)){
59. Column annotation = field.getAnnotation(Column.class);
60.
61. String fieldName = field.getName();
62. String ColumnName = annotation.name();
63. Class<?> type = annotation.type();
64. setValue(t,type,rs,ColumnName,fieldName);
65. }
66. }
67. }
68. return t;
69. }
70.
71. private static <T,S> void setValue(T t,Class<S> type,ResultSet rs,String columnName,String fieldName)throws Exception{
72. String setMethodName = "set"+fieldName.substring(0, 1).toUpperCase()+fieldName.substring(1);
73. Method setMethod = t.getClass().getMethod(setMethodName, new Class[]{type});
74. if(type == int.class){
75. setMethod.invoke(t, new Object[]{rs.getInt(columnName)});
76. }else if(type == byte.class){
77. setMethod.invoke(t, new Object[]{rs.getByte(columnName)});
78. }else if(type == short.class){
79. setMethod.invoke(t, new Object[]{rs.getShort(columnName)});
80. }else if(type == long.class){
81. setMethod.invoke(t, new Object[]{rs.getLong(columnName)});
82. }else if(type == String.class){
83. setMethod.invoke(t, new Object[]{rs.getString(columnName)});
84. }
85. }
86.
87. }
工具类Query
[java] view plain copy
1. package com.hc.utils;
2.
3. import java.lang.reflect.InvocationTargetException;
4. import java.sql.SQLException;
5. import java.util.Collection;
6.
7. import com.hc.cache.CacheManager;
8. import com.hc.core.AbstractExecute;
9. import com.hc.core.ExecuteFactory;
10. import com.hc.core.IEntity;
11.
12. public class Query {
13.
14. public static <T extends IEntity> Collection<T> query(Class<T> cls,String condition) throws SQLException{
15. AbstractExecute<T> execute = ExecuteFactory.getExecute();
16. return execute.query(cls, condition);
17. }
18.
19.
20. public static IEntity load(Class<?> cls,long id) throws SQLException {
21. IEntity entity = CacheManager.getEntity(cls.toString()+id);
22. if(entity != null){
23. return entity;
24. }
25. IEntity newInstance = null;
26. try {
27. newInstance = (IEntity)cls.getConstructor(new Class[]{}).newInstance(new Object[]{});
28. } catch (InstantiationException | IllegalAccessException
29. | IllegalArgumentException | InvocationTargetException
30. | NoSuchMethodException | SecurityException e) {
31. e.printStackTrace();
32. }
33. newInstance.get(id);
34. return newInstance;
35. }
36.
37. public static void execute(String sql)throws SQLException{
38. AbstractExecute<IEntity> execute = ExecuteFactory.getExecute();
39. execute.execute(sql);
40. }
41.
42. }
测试类
[java] view plain copy
1. package com.hc.execute;
2.
3. import com.hc.pool.IDPool;
4. import com.hc.sample.entity.UserEntity;
5.
6. public class TestExecute {
7.
8. /**
9. * @param args
10. */
11. public static void main(String[] args) throws Exception{
12.
13. UserEntity user = new UserEntity();
14. Long applyId = IDPool.getInstance().applyId();
15. user.setId(applyId);
16.
17.
18. user.setName("chujiinhui");
19.
20. //持久化用户
21. user.persist();
22.
23.
24. //查询此用户
25. user = (UserEntity)user.get(applyId);
26. System.out.println(user.getName());
27.
28.
29. //更新此用户
30. user.setName("hello");
31.
32.
33. user = (UserEntity)user.get(applyId);
34. System.out.println(user.getName());
35.
36.
37. }
38.
39. }
运行结果如下：
[plain] view plain copy
1. insert into user_m(id,name) values (?,?)
2. select * from user_m where 1=1 and id=?
3. chujiinhui
4. update user_m set name=? where id=?
5. select * from user_m where 1=1 and id=?
6. hello
查看数据库也存在已添加的数据。
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