我们都知道,要从表中选择所有列,可以使用

SELECT * FROM tableA

是否有一种方法可以在不指定所有列的情况下从表中排除列?

SELECT * [except columnA] FROM tableA

我所知道的唯一方法是手动指定所有列并排除不需要的列。这真的很耗时,所以我正在寻找方法来节省时间和精力,以及未来的维护表应该有更多/更少的列。


当前回答

是的,这是可能的(但不建议)。

CREATE TABLE contact (contactid int, name varchar(100), dob datetime)
INSERT INTO contact SELECT 1, 'Joe', '1974-01-01'

DECLARE @columns varchar(8000)

SELECT @columns = ISNULL(@columns + ', ','') + QUOTENAME(column_name)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'contact' AND COLUMN_NAME <> 'dob'
ORDER BY ORDINAL_POSITION

EXEC ('SELECT ' + @columns + ' FROM contact')

代码说明:

Declare a variable to store a comma separated list of column names. This defaults to NULL. Use a system view to determine the names of the columns in our table. Use SELECT @variable = @variable + ... FROM to concatenate the column names. This type of SELECT does not not return a result set. This is perhaps undocumented behaviour but works in every version of SQL Server. As an alternative you could use SET @variable = (SELECT ... FOR XML PATH('')) to concatenate strings. Use the ISNULL function to prepend a comma only if this is not the first column name. Use the QUOTENAME function to support spaces and punctuation in column names. Use the WHERE clause to hide columns we don't want to see. Use EXEC (@variable), also known as dynamic SQL, to resolve the column names at runtime. This is needed because we don't know the column names at compile time.

其他回答

你可以创建一个包含你想要选择的列的视图,然后你可以从视图中选择*…

右键单击对象资源管理器中的表,选择前1000行

它会列出所有列,而不是*。然后删除不需要的列。应该比你自己打快多了。

然后,当你觉得这有点太多的工作,获得Red Gate的SQL提示,并从tbl输入ssf,转到*并再次单击选项卡。

解决这个问题的最好方法是使用视图,您可以创建具有所需列的视图并从中检索数据

example

mysql> SELECT * FROM calls;
+----+------------+---------+
| id | date       | user_id |
+----+------------+---------+
|  1 | 2016-06-22 |       1 |
|  2 | 2016-06-22 |    NULL |
|  3 | 2016-06-22 |    NULL |
|  4 | 2016-06-23 |       2 |
|  5 | 2016-06-23 |       1 |
|  6 | 2016-06-23 |       1 |
|  7 | 2016-06-23 |    NULL |
+----+------------+---------+
7 rows in set (0.06 sec)

mysql> CREATE VIEW C_VIEW AS
    ->     SELECT id,date from calls;
Query OK, 0 rows affected (0.20 sec)

mysql> select * from C_VIEW;
+----+------------+
| id | date       |
+----+------------+
|  1 | 2016-06-22 |
|  2 | 2016-06-22 |
|  3 | 2016-06-22 |
|  4 | 2016-06-23 |
|  5 | 2016-06-23 |
|  6 | 2016-06-23 |
|  7 | 2016-06-23 |
+----+------------+
7 rows in set (0.00 sec)

如果我们谈论的是过程,它使用这个技巧来生成一个新的查询并立即执行它:

SELECT LISTAGG((column_name), ', ') WITHIN GROUP (ORDER BY column_id)
INTO var_list_of_columns
FROM ALL_TAB_COLUMNS
WHERE table_name = 'PUT_HERE_YOUR_TABLE'
AND column_name NOT IN ('dont_want_this_column','neither_this_one','etc_column');

我这样做了,它工作得很好(版本5.5.41):

# prepare column list using info from a table of choice
SET @dyn_colums = (SELECT REPLACE(
GROUP_CONCAT(`COLUMN_NAME`), ',column_name_to_remove','') 
FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE 
`TABLE_SCHEMA`='database_name' AND `TABLE_NAME`='table_name');

# set sql command using prepared columns
SET @sql = CONCAT("SELECT ", @dyn_colums, " FROM table_name");

# prepare and execute
PREPARE statement FROM @sql;
EXECUTE statement;