小编mar*_*pro的帖子

我正在使用带有H2的内存数据库测试Dao.我正在使用map传递一个int来执行它.此查询在Oracle SQL上运行正常,但在H2中没有成功.

DAO

    @Override
public int deleteCancelled(int days) {
    final Map<String, Object> namedParameters = new HashMap<String, Object>();

    namedParameters.put(DAYS, days);
    namedParameters.put(STATUS, StatusEnum.CANCELLED.toString());

    int updated = this.namedParameterJdbcTemplate.update(Query.QUERIES.DELETE_CANCELLED, namedParameters);

    return updated;
}

QUERIES

      public static final String DELETE_CANCELLED = "DELETE FROM MY_TABLE "
      + "WHERE UPDATE_TS < SYSDATE - :days AND STATUS = :status";

当我尝试在H2上执行此查询时,它返回:

错误

org.springframework.jdbc.UncategorizedSQLException: 
PreparedStatementCallback; uncategorized SQLException for SQL [DELETE FROM 
MY_TABLE WHERE UPDATE_TS < SYSDATE - ? AND STATUS = ?]; SQL state 
[HY004]; error code [50004]; Unknown data …

我正在使用 Spring-Boot 进行练习，我尝试搜索，但没有发现任何对我有用的东西。我试图返回一个转换 POJO 的 JSON，SB 应该自动执行此操作，但它返回：

2018-11-05 13：26：36.090警告1584 --- [nio-8080-exec-1] .wsmsDefaultHandlerExceptionResolver：已解决[org.springframework.http.converter.HttpMessageNotWritableException：找不到类型返回值的转换器：class com .example.demo.pelis.Foo]

这是我的 pom.xml：

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.0.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

还有我的 POJO：

public class Foo {

    private String bar;

    /**
     * @return the bar
     */
    public String getBar() {
        return bar;
    }

    /**
     * …