Question

此查询给出错误

ORA-00907：缺少右括号

我找不到任何括号问题

ngOnInit() {
    this.fetchArchiveForGroupChat(jid, connection);
}

fetchArchiveForGroupChat(jid, connection) {
    let maxNumberOfResults = "35";

    if (this.lastMessageUID !== -1 && !this.archiveMessagesCompleted) {
        console.log('Fetching second Archive...');

        this.nextSetOfArchivedMessages = []; // // Clear array on each request

        let iq = $iq({
                         type: "set",
                         id: generateUUIDv4(),
                     })
                 .c("query", {
                       xmlns: this.xmppNamespacesService.mamNS,
                       queryid: connection.getUniqueId("group-history")
                   })
    .c("x", {
      xmlns: this.xmppNamespacesService.dataFormsNS,
      type: "submit"
    })
    .c("field", {
      var: "FORM_TYPE",
      type: "hidden"
    })
    .c("value").t(this.xmppNamespacesService.mamNS)
    .up().up()
    .c("field", {
      var: "with"
    })
    .c("value").t(jid)
    .up().up().up() //to reach query
    .c("set", {
      xmlns: this.xmppNamespacesService.resultSetManagementNS
    })
    .c("max").t(maxNumberOfResults)
    .up()
    .c("before").t(this.lastMessageUID); //to retrieve the last n messages

  console.log("IQ to retrieve archive:", iq.tree());

  // Sending the IQ stanza to the server
  connection.sendIQ(iq, this.onReceivingArchive.bind(this),
    (e) => {
      console.log("An error has occurred while retrieving archive");
      console.log(e);
    }
  );
} else if (!this.archiveMessagesCompleted) {
  console.log("Fetching 1rst Archive");

  // Clear array on each request
  this.archiveList = [];
  this.nextSetOfArchivedMessages = [];

  let iq = $iq({
    type: "set",
    id: generateUUIDv4(),
  })
    .c("query", {
      xmlns: this.xmppNamespacesService.mamNS,
      queryid: connection.getUniqueId("group-history")
    })
    .c("x", {
      xmlns: this.xmppNamespacesService.dataFormsNS,
      type: "submit"
    })
    .c("field", {
      var: "FORM_TYPE",
      type: "hidden"
    })
    .c("value").t(this.xmppNamespacesService.mamNS)
    .up().up()
    .c("field", {
      var: "with"
    })
    .c("value").t(jid)
    .up().up().up() //to reach query
    .c("set", {
      xmlns: this.xmppNamespacesService.resultSetManagementNS
    })
    .c("max").t(maxNumberOfResults)
    .up()
    .c("before")//.t(this.lastMessageUID); // To retrieve the last n messages // To retrieve the last n messages

  console.log("IQ to retrieve archive:", iq.tree());

  // Sending the IQ stanza to the server
  connection.sendIQ(iq, this.onReceivingArchive.bind(this),
    (e) => {
      console.log("An error has occurred while retrieving archive");
      console.log(e);
    }
  );
}

Answer 1

您的问题是这个

ORDER BY id DESC

您不能在充当列表达式的子查询中使用ORDER BY。如果将其删除，您面临的错误将消失。

但是，我希望您使用with子句重写查询，因为两个子查询表达式都提取同一行。

WITH auth AS ( SELECT *
                 FROM ( SELECT pre_desig_id AS perpared_by,
                    pre_last_date AS pre_end_dt
                        FROM authorization
                      WHERE project_id = 5
          AND pre_desig_id = 48 ORDER BY id DESC )
 WHERE ROWNUM = 1 )
SELECT a.perpared_by,a.pre_end_dt
  FROM authorization au
  LEFT JOIN project p ON au.project_id = p.project_id
  LEFT JOIN designation d ON au.au_desig_id = d.desigid
 CROSS JOIN auth a;

Answer 2

您需要转换派生列的（prepared_by）子查询，类似于下面的pre_end_dt的子查询

Select 
       (Select pre_desig_id
          From (Select pre_desig_id,
                       row_number() over (order by ID desc) as rn
                  From Authorization
                 Where project_id = 5
                   and pre_desig_id = 48
                 )
         Where rn = 1)  as prepared_by,
       (Select pre_last_date
          From (Select pre_last_date,
                       row_number() over (order by ID desc) as rn
                  From Authorization
                 Where project_id = 5
                   and pre_desig_id = 48
                 )
         Where rn = 1) as pre_end_dt
  From Authorization au
  Left Join Project p
    on au.project_id = p.project_id
  Left Join Designation d
    on au.au_desig_id = d.desigid;

其中Order By ID Desc部分产生错误，应将其包装在额外的子查询中，否则编译器不允许直接使用Order By。即限制（rownum=1）和使用order by不允许在同一级别上使用，它们必须分别存在于外部和内部select语句中。

实际上，最好使用row_number()窗口分析函数，而不是rownum伪列，这在大多数情况下是不可信的，因为它是在排序之前生成的。

即使将Where rownum = 1与order by ID desc一起用于内部select语句也足以供您使用，而是使用row_number()函数养成习惯。

ORA-00907：右括号缺失，可能与SubQuery有关

2 个答案: