[mysql] How do I count columns of a table

For example :

tbl_ifo

id | name  | age | gender 
----------------------------
1  | John  |  15 |  Male
2  | Maria |  18 |  Female
3  | Steph |  19 |  Female
4  | Jay   |  21 |  Male

How can I count the columns of this table using mysql?

I have a more general answer; but I believe it is useful for counting the columns for all tables in a DB:

SELECT table_name, count(*)
FROM information_schema.columns
GROUP BY table_name;

To count the columns of your table precisely, you can get form information_schema.columns with passing your desired Database(Schema) Name and Table Name.

Reference the following Code:

SELECT count(*)
FROM information_schema.columns
WHERE table_schema = 'myDB'  
AND table_name = 'table1';

this query may help you

SELECT COUNT(COLUMN_NAME) FROM INFORMATION_SCHEMA.COLUMNS WHERE 
TABLE_CATALOG = 'database' AND TABLE_SCHEMA = 'dbo'
AND TABLE_NAME = 'tbl_ifo'

I think you want to know the total entries count in a table! For that use this code..

SELECT count( * ) as Total_Entries FROM tbl_ifo;

I think you need also to specify the name of the database:

SELECT COUNT(*)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_schema = 'SchemaNameHere'
  AND table_name = 'TableNameHere'

if you don't specify the name of your database, chances are it will count all columns as long as it matches the name of your table. For example, you have two database: DBaseA and DbaseB, In DBaseA, it has two tables: TabA(3 fields), TabB(4 fields). And in DBaseB, it has again two tables: TabA(4 fields), TabC(4 fields).

if you run this query:

SELECT count(*)
FROM information_schema.columns
WHERE table_name = 'TabA'

it will return 7 because there are two tables named TabA. But by adding another condition table_schema = 'SchemaNameHere':

SELECT COUNT(*)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_schema = 'DBaseA'
  AND table_name = 'TabA'

then it will only return 3.

Simply use mysql_fetch_assoc and count the array using count() function

$cs = mysql_query("describe tbl_info");
$column_count = mysql_num_rows($cs);

Or just:

$column_count = mysql_num_rows(mysql_query("describe tbl_info"));