# 修改

对数据库中的数据进行修改

```java
/**
 * 数据更新
 * @param tableName 表名
 * @param dataMap set的更新的数据
 * @param searchMap where后面的语句条件数据
 * @return 更新之后的返回值
 */
public NeoMap update(String tableName, NeoMap dataMap, NeoMap searchMap) {}
public <T> T update(String tableName, T setEntity, NeoMap searchMap, NamingChg namingChg) {}
public <T> T update(String tableName, T setEntity, NeoMap searchMap) {}
public <T> T update(String tableName, T setEntity, T searchEntity) {}
public NeoMap update(String tableName, NeoMap dataMap, Columns columns) {}
public <T> T update(String tableName, T entity, Columns columns, NamingChg namingChg) {}
public <T> T update(String tableName, T entity, Columns columns) {}

public NeoMap update(String tableName, NeoMap dataMap) {}
public <T> T update(String tableName, T entity) {}

public <T> T update(String tableName, T entity, Columns columns) {}
public <T> T update(String tableName, T entity, Columns columns, NamingChg namingChg) {}
```

`update`的重载函数有点多，但是终究只是对`update`对应的sql的简单拼装，其中对应的参数如下

| 参数           | 类型        | 详解                                                         |
| ------------ | --------- | ---------------------------------------------------------- |
| tableName    | String    | 表名                                                         |
| dataMap      | NeoMap    | update待更新的数据                                               |
| setEntity    | T         | update待更新的数据，跟dataMap一样，只是这里是实体形式                          |
| searchMap    | NeoMap    | update更新的条件，用于在where后面的子句中                                 |
| searchEntity | T         | update更新的条件，用于在where后面的子句中，这里是实体形式                         |
| columns      | Columns   | 指定的在dataMap数据的对应的列，以节省再输入的麻烦，可以为NeoMap指定列，也可以为entity实体指定属性 |
| namingChg    | NamingChg | 待插入的数据，通过该字符转换可以跟数据库字段对应上                                  |

例子：

```java
@Test
@SneakyThrows
public void testUpdate1(){
  // update neo_table1 set `group`=? where `group` =  ? and `name` =  ?
  neo.update(TABLE_NAME, NeoMap.of("group", "ok2"), NeoMap.of("group", "group2", "name", "name"));
}

@Test
@SneakyThrows
public void testUpdate2(){
  // update neo_table1 set `group`=?, `name`=? where `name` =  ?
  show(neo.update(TABLE_NAME, NeoMap.of("group", "ok3", "name", "name"), Columns.of("name")));
}

@Test
@SneakyThrows
public void testUpdate3(){
  DemoEntity input = new DemoEntity();
  input.setGroup("group2");
  // update neo_table1 set `group`=? where `group` =  ? and `name` =  ?
  show(neo.update(TABLE_NAME, input, NeoMap.of("group", "group1", "name", "name")));
}

@Test
@SneakyThrows
public void testUpdate4(){
  DemoEntity search = new DemoEntity();
  search.setGroup("group1");

  DemoEntity data = new DemoEntity();
  data.setGroup("group2");
  // update neo_table1 set `group`=? where `group` =  ?
  show(neo.update(TABLE_NAME, data, search));
}

/**
     * 指定某个列作为查询条件
     */
@Test
@SneakyThrows
public void testUpdate5(){
  // update neo_table1 set `group`=?, `name`=? where `group` =  ?
  show(neo.update(TABLE_NAME, NeoMap.of("group", "group1", "name", "name2"), Columns.of("group")));
}

/**
     * 指定某个列作为查询条件
     */
@Test
@SneakyThrows
public void testUpdate8(){
  DemoEntity search = new DemoEntity();
  search.setGroup("group555");
  search.setName("name333");
  // update neo_table1 set `group`=?, `name`=? where `name` =  ?
  show(neo.update(TABLE_NAME, search, Columns.of("name")));
}

/**
     * 指定某个列作为查询条件
     */
@Test
@SneakyThrows
public void testUpdate9(){
  DemoEntity search = new DemoEntity();
  search.setGroup("group555");
  search.setName("name333");
  search.setUserName("userName2222");
  show(neo.update(TABLE_NAME, search, Columns.of("userName"), NamingChg.UNDERLINE));
}
```

**注意：**\
对于如下两个函数，可以看到没有指定搜索条件，对于这种，这里采用的是，如果dataMap和entity中含有主键，则默认会将该主键设置为后面的搜索条件，比如下面的例子

```java
public NeoMap update(String tableName, NeoMap dataMap) {}
public <T> T update(String tableName, T entity) {}
```

```java
/**
 * 不指定则，默认查找搜索条件中的主键列对应的值为搜索条件
 */
@Test
@SneakyThrows
public void testUpdate6(){
  // update neo_table1 set `group`=?, `id`=?, `name`=? where `id` =  ?
  show(neo.update(TABLE_NAME, NeoMap.of("id", 2, "group", "group222", "name", "name2")));
}

/**
 * 指定某个列作为查询条件，默认查找搜索条件中的主键列对应的值为搜索条件
 */
@Test
@SneakyThrows
public void testUpdate7(){
  DemoEntity search = new DemoEntity();
  search.setId(281L);
  search.setGroup("group555");
  // update neo_table1 set `group`=?, `id`=? where `id` =  ?
  show(neo.update(TABLE_NAME, search));
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://simons.gitbook.io/neo/basefun/update.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.