的Oracle PL/SQL找到最大和最小每列的

Question

在这里第一个问题，感谢事先所有的答复。我正在尝试创建一个PL/SQL代码，它将查找表中每个变量的最大值和最小值。该表格非常大，约100多个变量和超过百万条记录。

编辑：我想创建一个循环，而不是一个select语句，我将不得不为每一列键入最大和最小100+倍。

理想情况下，我是刨了SELECT语句作为变量来从用户那里获取的统计数据表中的列名，然后创建选择最大值和最小值从表中这些变量中的每一个的循环。

另外，表中有不同类型的列。所以我也需要找到一种方法来过滤掉其他不是数字的类型。再次

感谢下面的所有响应。

Answer 1

SELECT MIN(column001) AS min_column001, 
     MAX(column001) AS max_column001, 
     MIN(column002) AS min_column002, 
     MAX(column002) AS max_column002, 
     MIN(column003) AS min_column003, 
     MAX(column003) AS max_column003, 
     MIN(column004) AS min_column004, 
     MAX(column004) AS max_column004, 

... 

     MIN(column099) AS min_column099, 
     MAX(column099) AS max_column099, 
     MIN(column100) AS min_column100, 
     MAX(column100) AS max_column100 
FROM YourTable; 

Answer 2

为了避免在键入的所有列名，执行以下查询：

SELECT 'min('||column_name||'), max('||column_name||'), ' 
FROM user_tab_cols 
WHERE table_name = 'myTableName'; 

然后将结果复制到查询缓冲区并构建它周围的查询的其余部分。那就是：

• 添加select第一行之前
• 添加from任何你想要的表
• 删除最后一个逗号

你也可以这样做只是通过选择列名：

SELECT column_name 
FROM user_tab_cols 
WHERE table_name = 'myTableName'; 

将输出复制到Excel（或您最喜欢的电子表格）中d使用公式生成代码。

Answer 3

可以动态地生成需要从表中

SELECT 'SELECT ' 
      || LISTAGG('MIN("' || COLUMN_NAME || '") AS "MIN_' || COLUMN_NAME || '"' 
        || ',MAX("' || COLUMN_NAME || '") AS "MAX_' || COLUMN_NAME || '"' 
       , ',') WITHIN GROUP (ORDER BY COLUMN_ID) 
      || ' FROM TBL' 
    FROM USER_TAB_COLUMNS 
    WHERE TABLE_NAME = 'YOURTABLENAME'; 

其然后可以复制选择所有列，并运行到输出每一列的最小值和最大值的SQL。

如果你在做这一切的动态再坚持（假设各列不同的数据类型）：

SQL Fiddle

的Oracle 11g R2架构设置：

CREATE TABLE tbl (
    asdfghjkl NUMBER, 
    poiuytrew VARCHAR2(3), 
    oiuytrewq DATE, 
    sdfghjkla NUMBER, 
    zxcvbnmcv NUMBER, 
    mnbvcxznb NUMBER, 
    qwertyuio NUMBER, 
    wertyuiop NUMBER 
); 

INSERT INTO tbl 
SELECT LEVEL, LPAD(TO_CHAR(LEVEL), 3, '0'), TRUNC(SYSDATE) - LEVEL, LEVEL+1, 10-LEVEL, LEVEL, ABS(5-LEVEL), POWER(0.9, LEVEL) 
FROM DUAL 
CONNECT BY LEVEL < 10; 

CREATE TABLE test AS SELECT * FROM tbl WHERE 1 = 0; 

查询1：

SELECT * FROM tbl 

Results：

| ASDFGHJKL | POIUYTREW |      OIUYTREWQ | SDFGHJKLA | ZXCVBNMCV | MNBVCXZNB | QWERTYUIO | WERTYUIOP | 
|-----------|-----------|---------------------------------|-----------|-----------|-----------|-----------|-------------| 
|   1 |  001 | December, 15 2013 00:00:00+0000 |   2 |   9 |   1 |   4 |   0.9 | 
|   2 |  002 | December, 14 2013 00:00:00+0000 |   3 |   8 |   2 |   3 |  0.81 | 
|   3 |  003 | December, 13 2013 00:00:00+0000 |   4 |   7 |   3 |   2 |  0.729 | 
|   4 |  004 | December, 12 2013 00:00:00+0000 |   5 |   6 |   4 |   1 |  0.6561 | 
|   5 |  005 | December, 11 2013 00:00:00+0000 |   6 |   5 |   5 |   0 |  0.59049 | 
|   6 |  006 | December, 10 2013 00:00:00+0000 |   7 |   4 |   6 |   1 | 0.531441 | 
|   7 |  007 | December, 09 2013 00:00:00+0000 |   8 |   3 |   7 |   2 | 0.4782969 | 
|   8 |  008 | December, 08 2013 00:00:00+0000 |   9 |   2 |   8 |   3 | 0.43046721 | 
|   9 |  009 | December, 07 2013 00:00:00+0000 |  10 |   1 |   9 |   4 | 0.387420489 | 

查询2：

DECLARE 
    min_sql CLOB; 
    max_sql CLOB; 
    min_rec tbl%ROWTYPE; 
    max_rec tbl%ROWTYPE; 
BEGIN 
    -- Generate the SQL to find the minimums 
    SELECT 'SELECT ' 
      || LISTAGG('MIN("' || COLUMN_NAME || '")', ',') 
       WITHIN GROUP (ORDER BY COLUMN_ID) 
      || ' FROM TBL' 
    INTO min_sql 
    FROM USER_TAB_COLUMNS 
    WHERE TABLE_NAME = 'TBL'; 

    -- Generate the SQL to find the maximums 
    SELECT 'SELECT ' 
      || LISTAGG('MAX("' || COLUMN_NAME || '")', ',') 
       WITHIN GROUP (ORDER BY COLUMN_ID) 
      || ' FROM TBL' 
    INTO max_sql 
    FROM USER_TAB_COLUMNS 
    WHERE TABLE_NAME = 'TBL'; 

    -- Execute the SQL to find the minimums and put the 
    -- results into a %ROWTYPE record (to ensure dataypes 
    -- match). 
    EXECUTE IMMEDIATE min_sql INTO min_rec; 

    -- Execute the SQL to find the maximums and put the 
    -- results into a %ROWTYPE record (to ensure dataypes 
    -- match). 
    EXECUTE IMMEDIATE max_sql INTO max_rec; 

    -- Do something with the minimums 
    INSERT INTO test VALUES min_rec; 

    -- Do something with the maximums 
    INSERT INTO test VALUES max_rec; 
END; 

查询3：

SELECT * FROM test 

Results：

| ASDFGHJKL | POIUYTREW |      OIUYTREWQ | SDFGHJKLA | ZXCVBNMCV | MNBVCXZNB | QWERTYUIO | WERTYUIOP | 
|-----------|-----------|---------------------------------|-----------|-----------|-----------|-----------|-------------| 
|   1 |  001 | December, 07 2013 00:00:00+0000 |   2 |   1 |   1 |   0 | 0.387420489 | 
|   9 |  009 | December, 15 2013 00:00:00+0000 |  10 |   9 |   9 |   4 |   0.9 |