Question

我创建了一个临时表（@temptable），其中我将列留空了，因为我将用另一个select语句填充它。

我有一个包含5行的表格：

 BookNum | BookDesc | BookDate | ......
---------|----------|----------|--------
 00      | A sto... | 6/6/2013 | ......
 00      | {null}   | {null}   | ......
 02      | The t... | 6/6/2013 | ......
 00      | {null}   | 6/6/2013 | ......
 02      | {null}   | 6/6/2013 | ......

我的temptable有一个包含BookNum的列：

...... | total_books | title | BookCode | CountOfBook
-------|-------------|-------|----------|-------------
...... |      4      | Once  |    00    |   {null}
...... |      4      | Once  |    00    |   {null}
...... |      4      | Once  |    00    |   {null}
...... |      4      | Once  |    00    |   {null}
...... |      4      | Once  |    00    |   {null}
...... |      4      | Once  |    00    |   {null}
...... |      4      | Four  |    02    |   {null}
...... |      4      | Four  |    02    |   {null}

我想要做的是从书籍表中获取一本特定书籍的书数，其中日期不为空，并将其放入我的@temptable的CountOfBook列中，但我可以'似乎弄清楚了。它应该是这样的：

...... | total_books | title | BookCode | CountOfBook
-------|-------------|-------|----------|-------------
...... |      4      | Once  |    00    |     2
...... |      4      | Once  |    00    |     2
...... |      4      | Once  |    00    |     2
...... |      4      | Once  |    00    |     2
...... |      4      | Once  |    00    |     2
...... |      4      | Once  |    00    |     2
...... |      4      | Four  |    02    |     2
...... |      4      | Four  |    02    |     2

因为每本书中有2本日期不为空。

Answer 1

试试这个，你可以在更新语句中使用子查询 - 这对你有帮助 -

   update tempTable t
    set CountOfBook = (select count(*) as CountOfBook_2 
                        from Books 
                       where BookData is not null
                       Group by BookCode 
                       having BookCode=t.BookCode );

sqlfiddle示例 - ＆gt; 使用oracle 11 g =＆gt; fiddle

<强>更新尝试使用此：link referred

   update tempTable 
    set CountOfBook = (select count(*) as CountOfBook_2 
                        from Books 
                       where BookData is not null
                       Group by BookCode 
                       having BookCode=t.BookCode)
    FROM tempTable as t;

使用两个表中的数据更新临时表

1 个答案: