嵌入式SQL中的UNION子句

Question

我正在使用ingres 10S SQL，並且試圖在嵌入式SQL C程序中編寫以下SQL語句。 它可以作為獨立的SQL腳本正常運行，但是編譯eSQL程序會收到錯誤

%% Error in file localtask.sc, Line 498: E_EQ0244 Syntax error on 'union'.

INSERT INTO nr301_tab2 (authority_id)
SELECT a.authority_id
FROM nrremdets a, nrstatus_hierarchy z
WHERE a.authority_id = z.authority_id
UNION
SELECT a.authority_id
FROM nrsumsamts a, nrsumsdets b
WHERE a.authority_id = b.authority_id;

（第498行是UNION行）該UNION子句有什么問題？

Answer 1

只需稍微調整一下查詢，它就可以工作。 嘗試這個：

INSERT INTO nr301_tab2 (authority_id)
SELECT authority_id
FROM
    (SELECT a.authority_id
     FROM nrremdets a, nrstatus_hierarchy z
     WHERE a.authority_id = z.authority_id
     UNION
     SELECT a.authority_id
     FROM nrsumsamts a, nrsumsdets b
     WHERE a.authority_id = b.authority_id) Result

想法是合並結果集，這將創建一個新的結果集，將其插入到表中一次。 通過添加括號，我們確保會發生這種情況。