如何在Oracle Developer上運行此查詢？

Question

我有這個疑問的PowerShell腳本的一部分，它運行SQL Server上確定，但未能在Oracle

select case when OBJECT_ID (N'INTERFACE_DEFINITION', N'U') is null then 0 else 1 end 

這裏是錯誤：ORA-00923：FROM關鍵字未找到預期

有沒有做這項工作需要做一些改變？

謝謝。

Answer 1

The DUAL table is present in every Oracle database. This special table contains just one column. The column is named DUMMY, and it has a datatype of VARCHAR2(1). The DUAL table contains only one row. That row has a value in DUMMY of ‘X’.

The purpose of DUAL is simple—to have something to run a SELECT statement against when you don’t wish to retrieve any data in particular but instead simply wish to run a SELECT statement to get some other task accomplished.

檢驗物品存在：

OBJECT_ID (N'INTERFACE_DEFINITION', N'U') 

在Oracle中，你可以使用這個查詢：

select count(*) from all_objects where object_name = 'INTERFACE_DEFINITION'; 

all_objects不一定會顯示在所有對象數據庫。它僅向您顯示當前用戶具有特權的對象。