正則表達式將LIMIT語法轉換爲SqlServer TOP語法

我有一些爲PostgreSQL編寫的查詢字符串，我必須將它們轉換爲SqlServer。我使用C＃6正則表達式將LIMIT語法轉換爲SqlServer TOP語法

爲了從LIMIT語法TOP語法我已經寫了下面的簡單的regex轉換：

SELECT ([\S\s]*)LIMIT (\d+) -> SELECT TOP $2 $1

整條生產線的代碼是：

return Regex.Replace(query, @"SELECT ([\S\s]*)LIMIT (\d+)", "SELECT TOP $2 $1", RegexOptions.RightToLeft);

現在，eveything對於簡單的查詢工作正常，但對於子查詢不起作用：TOP字符串每次都放入超級父查詢中。

嘗試例如下面的查詢：

SELECT b3.aaa, 
     b3.count 
FROM 
(
    SELECT CONCAT(b.foo/100.0, '-', (b.foo + 10)/100.0) AS aaa, 
         COUNT(b.foo) AS count 
    FROM 
    (
     SELECT b2.foo - (b2.foo % 10) AS foo 
     FROM 
     (
      SELECT CAST(b.foo * 100 AS INT) AS foo 
      FROM eee b 
       INNER JOIN bar f ON b.bar_id = f.id 
      WHERE b.foo < 1 
        AND f.nome = 'aaa' 
     ) b2 
    ) b 
    GROUP BY b.foo 
    ORDER BY b.foo 
    LIMIT 10 
)

它轉換爲：

SELECT TOP 10 b3.aaa, 
     b3.count 
FROM 
(
    SELECT CONCAT(b.foo/100.0, '-', (b.foo + 10)/100.0) AS aaa, 
         COUNT(b.foo) AS count 
    FROM 
    (
     SELECT b2.foo - (b2.foo % 10) AS foo 
     FROM 
     (
      SELECT CAST(b.foo * 100 AS INT) AS foo 
      FROM eee b 
       INNER JOIN bar f ON b.bar_id = f.id 
      WHERE b.foo < 1 
        AND f.nome = 'aaa' 
     ) b2 
    ) b 
    GROUP BY b.foo 
    ORDER BY b.foo 
)

，而我想有

SELECT b3.aaa, 
     b3.count 
FROM 
(
    SELECT TOP 10 CONCAT(b.foo/100.0, '-', (b.foo + 10)/100.0) AS aaa, 
         COUNT(b.foo) AS count 
    FROM 
    (
     SELECT b2.foo - (b2.foo % 10) AS foo 
     FROM 
     (
      SELECT CAST(b.foo * 100 AS INT) AS foo 
      FROM eee b 
       INNER JOIN bar f ON b.bar_id = f.id 
      WHERE b.foo < 1 
        AND f.nome = 'aaa' 
     ) b2 
    ) b 
    GROUP BY b.foo 
    ORDER BY b.foo 
)

我應該怎麼寫正則表達式我需要？

來源

2017-07-05 Rowandish

這工作好與我做處理援引括號一些變化：

var pattern = @"SELECT ((?:[^'()]|(?>'[^']+')|(?<open>\()|(?<-open>\)))+(?(open)(?!)))LIMIT (\d+)"; 

query = Regex.Replace(query, pattern, "SELECT TOP $2 $1");

來源

2017-07-05 22:58:45 NetMage

我無法測試您的正則表達式，因爲它有一個模式錯誤，請你解決這個問題？謝謝 – Rowandish

我複製並粘貼它，它執行得很好。 – NetMage

對不起，我在reg101網站上進行了模式錯誤測試，是我的錯。我測試了它，它工作正常，非常感謝！ – Rowandish

正則表達式將LIMIT語法轉換爲SqlServer TOP語法

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