从 java 调用 Postgres 存储过程，要返回的表

Question

我做了一个 Postgres 存储过程：

CREATE OR REPLACE FUNCTION GetUser(ipUserId integer)
RETURNS setof users AS $$
BEGIN
  IF ipUserId is null THEN
    return query select * from users A order by modifieddate desc;
  END IF;
  return query select * from users where iduser = ipUserId;
END;
$$ LANGUAGE plpgsql;

我尝试在 java 中使用它，如下所示：

    StoredProcedureQuery query = entityManager.createStoredProcedureQuery("GetUser").
            registerStoredProcedureParameter("ipUserId",
                    Integer.class, ParameterMode.IN)
            .registerStoredProcedureParameter("users",
                    List.class, ParameterMode.OUT)
            .setParameter("postId", 1);

或者

 StoredProcedureQuery query = entityManager.createStoredProcedureQuery("GetUser")
                .registerStoredProcedureParameter(1,void.class, ParameterMode.REF_CURSOR)
                .registerStoredProcedureParameter(2,Integer.class, ParameterMode.IN)
                .setParameter(2, ipIdUser);

我想将结果存储在列表中。

我应该怎么做，因为我遇到了各种各样的错误？

更新：

这些是错误：

javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: Error calling CallableStatement.getMoreResults
Caused by: org.hibernate.exception.SQLGrammarException: Error calling CallableStatement.getMoreResults
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.result.internal.OutputsImpl.convert(OutputsImpl.java:79)
    at org.hibernate.result.internal.OutputsImpl.<init>(OutputsImpl.java:56)
    at org.hibernate.procedure.internal.ProcedureOutputsImpl.<init>(ProcedureOutputsImpl.java:34)
    at org.hibernate.procedure.internal.ProcedureCallImpl.buildOutputs(ProcedureCallImpl.java:453)
    at org.hibernate.procedure.internal.ProcedureCallImpl.getOutputs(ProcedureCallImpl.java:404)
    at org.hibernate.procedure.internal.ProcedureCallImpl.outputs(ProcedureCallImpl.java:663)
    at org.hibernate.procedure.internal.ProcedureCallImpl.getResultList(ProcedureCallImpl.java:751)
    ... 21 more
Caused by: org.postgresql.util.PSQLException: A CallableStatement was executed with an invalid number of parameters

Answer 1

您可以尝试使用CallableStatement。 假设您的Connection变量正常：

CallableStatement stmt = con.prepareCall("{call SCHEMA.PROCEDURE_NAME (?, ?)}");
stmt.setInt(1, custom_var);
stmt.registerOutParameter(2, OracleTypes.INTEGER);
stmt.execute();

要获得结果： stmt.getInt(3); stmt.getString(4) stmt.getInt(3); stmt.getString(4)

如果无法成功，请尝试使用JdbcTemplate：

SimpleJdbcCall call = new SimpleJdbcCall(this.jdbcTemplate).withSchemaName(SCHEMA).withProcedureName(PROC);
MapSqlParameterSource params = new MapSqlParameterSource();
params.addValue("ipUserId", custom_var);
Map out = call.execute(params);

要获取单个结果： Integer.parseInt("" + out.get("OUT_PARAM_NAME")); (String) out.get("OUT_PARAM_NAME2")); Integer.parseInt("" + out.get("OUT_PARAM_NAME")); (String) out.get("OUT_PARAM_NAME2"));

或者，您可以将所有结果保存在列表中以供日后使用：

SimpleJdbcCall call = new SimpleJdbcCall(this.jdbcTemplate);
List<Map<String, Object>> rows = call.getJdbcTemplate().queryForList(PROC_STRING, new Object[] { param1, param2 });

Answer 2

我找到了一个非常简单的解决方案，只需执行一个SQL查询以使用hibernate调用该过程即可。

    String SqlString = "select * from GetUser({0})";

    if (ipIdUser == null )
        SqlString = MessageFormat.format(SqlString, "NULL");
    else
        SqlString = MessageFormat.format(SqlString, ipIdUser);

    LOGGER.info("SqlSting =" + SqlString);

    return entityManager.createNativeQuery(SqlString, User.class)
            .getResultList();

Answer 3

为什么不对StoredProcedureQuery使用getResultList ？ 这避免了必须进行字符串操作。

List<User> users = entityManager.createStoredProcedureQuery("GetUser")
  .registerStoredProcedureParameter("ipUserId", Integer.class, ParameterMode.IN)
  .setParameter("ipUserId", ipIdUser)
  .getResultList();

Answer 4

In your case, you have a table valued function that happens to map to an actual table, so the approach using the JPA native query is elegant too, but perhaps your projection is something different, or you return multiple nested data structures, arrays, etc ，使用 JPA 可能会很棘手。

jOOQ 为您的所有过程生成代码，包括表值函数。 例如，您将有一个包含getUser方法的Routines class，您可以像这样查询：

Result<GetUser> result = Routines.getUser(configuration, 1);

您还可以使用表值 function 作为查询中的实际表，如下所示：

Result<GetUser> result = ctx.selectFrom(GETUSER(1)).fetch();

免责声明：我在 jOOQ 背后的公司工作。