如何使用MySQL在所有表中标识存在的列？

要标识列名，请在MySQL中使用INFORMATION_SCHEMA.COLUMNS。这是语法-

select table_name,column_name
from INFORMATION_SCHEMA.COLUMNS
where table_schema = SCHEMA()
andcolumn_name='anyColumnName';

让我们实现上面的查询，以便识别在所有表中都存在的列。在这里，我们发现存在列EmployeeAge-

select table_name,column_name
   FROM INFORMATION_SCHEMA.COLUMNS
   WHERE table_schema = SCHEMA()
   AND column_name='EmployeeAge';

这将产生以下输出，显示带有特定列“ EmployeeAge”的表-

+---------------+-------------+
| TABLE_NAME    | COLUMN_NAME |
+---------------+-------------+
| demotable1153 | EmployeeAge |
| demotable1297 | EmployeeAge |
| demotable1303 | EmployeeAge |
| demotable1328 | EmployeeAge |
| demotable1378 | EmployeeAge |
| demotable1530 | EmployeeAge |
| demotable1559 | EmployeeAge |
| demotable1586 | EmployeeAge |
| demotable1798 | EmployeeAge |
| demotable1901 | EmployeeAge |
| demotable511  | EmployeeAge |
| demotable912  | EmployeeAge |
+---------------+-------------+
12 rows in set (0.00 sec)

为了证明，让我们检查上表的描述-

desc demotable1153;

这将产生以下输出，显示demotable1153中EmployeeAge列的存在-

+--------------+-------------+------+-----+---------+----------------+
| Field        | Type        | Null | Key | Default | Extra          |
+--------------+-------------+------+-----+---------+----------------+
| EmployeeId   | int(11)     | NO   | PRI | NULL    | auto_increment |
| EmployeeName | varchar(40) | YES  | MUL | NULL    |                |
| EmployeeAge  | int(11)     | YES  |     | NULL    |                |
+--------------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)