我试图使用一个选择语句从某个MySQL表中获得除一个以外的所有列。有什么简单的方法吗?
编辑:在这个表格中有53列(不是我的设计)
当前回答
也许我有一个解决Jan Koritak指出的矛盾的方法
SELECT CONCAT('SELECT ',
( SELECT GROUP_CONCAT(t.col)
FROM
(
SELECT CASE
WHEN COLUMN_NAME = 'eid' THEN NULL
ELSE COLUMN_NAME
END AS col
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'employee' AND TABLE_SCHEMA = 'test'
) t
WHERE t.col IS NOT NULL) ,
' FROM employee' );
表:
SELECT table_name,column_name
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'employee' AND TABLE_SCHEMA = 'test'
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
table_name column_name
employee eid
employee name_eid
employee sal
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
查询结果:
'SELECT name_eid,sal FROM employee'
其他回答
(不要在大桌子上尝试，结果可能是……令人惊讶的!)
临时表
DROP TABLE IF EXISTS temp_tb;
CREATE TEMPORARY TABLE ENGINE=MEMORY temp_tb SELECT * FROM orig_tb;
ALTER TABLE temp_tb DROP col_a, DROP col_f,DROP col_z; #// MySQL
SELECT * FROM temp_tb;
DROP语法可能因数据库而异
如果愿意，可以使用SQL生成SQL，并对生成的SQL进行评估。这是一种通用的解决方案，因为它从信息模式中提取列名。下面是一个Unix命令行的示例。
替换
MYSQL的MYSQL命令 带有表名的TABLE 包含排除字段名的EXCLUDEDFIELD
echo $(echo 'select concat("select ", group_concat(column_name) , " from TABLE") from information_schema.columns where table_name="TABLE" and column_name != "EXCLUDEDFIELD" group by "t"' | MYSQL | tail -n 1) | MYSQL
实际上，您只需要以这种方式提取列名一次，就可以构造排除该列的列列表，然后只需使用已构造的查询。
比如:
column_list=$(echo 'select group_concat(column_name) from information_schema.columns where table_name="TABLE" and column_name != "EXCLUDEDFIELD" group by "t"' | MYSQL | tail -n 1)
现在可以在构造的查询中重用$column_list字符串。
如果你想排除一个字段的值，例如安全问题/敏感信息，你可以检索该列为空。
e.g.
SELECT *, NULL AS salary FROM users
如果它总是相同的一列，那么你可以创建一个不包含它的视图。
否则，不，我不这么认为。
这个问题是关于MySQL的，但我仍然认为值得一提的是，至少谷歌BigQuery和H2原生支持* EXCEPT语法。
SELECT * FROM actor
生产:
|actor_id|first_name|last_name |last_update |
|--------|----------|------------|-----------------------|
|1 |PENELOPE |GUINESS |2006-02-15 04:34:33.000|
|2 |NICK |WAHLBERG |2006-02-15 04:34:33.000|
|3 |ED |CHASE |2006-02-15 04:34:33.000|
而
SELECT * EXCEPT (last_update) FROM actor
生产:
|actor_id|first_name|last_name |
|--------|----------|------------|
|1 |PENELOPE |GUINESS |
|2 |NICK |WAHLBERG |
|3 |ED |CHASE |
也许，MySQL的未来版本也会支持这种语法?
