How do I use `SHOW COLUMNS` as a valid data source for a table?

For this, you can use INFORMATION_SCHEMA.COLUMNS as shown in the following syntax −

SELECT *FROM (SELECT *FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME= 'yourTableName')
anyAliasName;

Let us first create a table:

mysql> create table DemoTable
(
   StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   StudentFirstName varchar(20),
   StudentLastName varchar(20),
   StudentAge int
);
Query OK, 0 rows affected (1.51 sec)

Here is the query to use `SHOW COLUMNS` as a valid data source −

mysql> SELECT *FROM (SELECT *FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME= 'DemoTable')tbl;

This will produce the following output −

+---------------+--------------+-------------+------------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+--------------------+-----------------+-------------+------------+----------------+---------------------------------+----------------+-----------------------+--------+
| TABLE_CATALOG | TABLE_SCHEMA | TABLE_NAME | COLUMN_NAME       | ORDINAL_POSITION | COLUMN_DEFAULT | IS_NULLABLE | DATA_TYPE | CHARACTER_MAXIMUM_LENGTH | CHARACTER_OCTET_LENGTH | NUMERIC_PRECISION | NUMERIC_SCALE | DATETIME_PRECISION | CHARACTER_SET_NAME | COLLATION_NAME | COLUMN_TYPE | COLUMN_KEY | EXTRA | PRIVILEGES | COLUMN_COMMENT | GENERATION_EXPRESSION | SRS_ID |
+---------------+--------------+-------------+------------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+--------------------+-----------------+-------------+------------+----------------+---------------------------------+----------------+-----------------------+--------+
| def           | sample       | DemoTable   | StudentId        | 1                | NULL           | NO          | int       | NULL                     | NULL                   | 10                 | 0 | NULL | NULL | NULL | int(11) | PRI | auto_increment | select,insert,update,references | | | NULL |
| def           | sample       | DemoTable   | StudentFirstName | 2                | NULL           | YES         | varchar   | 20                       | 60                     | NULL               | NULL | NULL | utf8 | utf8_general_ci | varchar(20) | | | select,insert,update,references | | | NULL |
| def           | sample       | DemoTable   | StudentLastName  | 3                | NULL           | YES         | varchar   | 20                       | 60                     | NULL               | NULL | NULL | utf8 | utf8_general_ci | varchar(20) | | | select,insert,update,references | | | NULL |
| def           | sample       | DemoTable   | StudentAge       | 4                | NULL           | YES         | int       | NULL                     | NULL                   | 10                 | 0 | NULL | NULL | NULL | int(11) | | | select,insert,update,references | | | NULL |
+---------------+--------------+-------------+------------------+------------------+----------------+-------------+-----------+--------------------------+------------------------+-------------------+---------------+--------------------+--------------------+-----------------+-------------+------------+----------------+---------------------------------+----------------+-----------------------+--------+
4 rows in set (0.00 sec)

Arjun Thakur

Published on 29-Apr-2019 09:17:00

• Related Questions & Answers
• How do I show unique constraints of a table in MySQL?
• How do I show the schema of a table in a MySQL database?
• How do I list all the columns in a MySQL table?
• How can I use MySQL subquery as a table in FROM clause?
• How to create a table TAB2 having same attributes & columns as for table TAB1
• How do I use tabHost for Android?
• How do I show a MySQL warning that just happened?
• How do I use the ternary operator ( ? : ) in PHP as a shorthand for “if / else”?
• How do I view the auto_increment value for a table in MySQL?
• How do we include attributes for table columns in HTML?
• How do I get the current AUTO_INCREMENT value for a table in MySQL?
• How can I return the values of columns from MySQL table as a set of values?
• How do I alter a MySQL table column defaults?
• How do I plot only a table in Matplotlib?
• How do I remove a uniqueness constraint from a MySQL table?