Find the number of columns in a table

Question

It is possible to find the number of rows in a table:

select count(*) from tablename

Is it possible to find the number of columns in a tabl

Answer 1

Here is how you can get a number of table columns using Python 3, sqlite3 and pragma statement:

con = sqlite3.connect(":memory:")    
con.execute("CREATE TABLE tablename (d1 VARCHAR, d2 VARCHAR)")
cur = con.cursor()
cur.execute("PRAGMA table_info(tablename)")
print(len(cur.fetchall()))

Source

Answer 2

SELECT count(*) FROM information_schema.`COLUMNS` C
WHERE table_name = 'your_table_name'
AND TABLE_SCHEMA = "your_db_name"

Answer 3

Can get using following sql statement:

select count(*) Noofcolumns from SYSCOLUMNS where id=(select id from SYSOBJECTS where name='table_name')

Answer 4

A MySQL answer adapted slightly from the MSDN example for MySqlDataReader.GetValues:

//assumes you've already created a connection, opened it, 
//and executed a query to a reader

while(reader.Read())
{
    Object[] values = new Object[reader.FieldCount];
    int fieldCount = reader.GetValues(values);

    Console.WriteLine("\nreader.GetValues retrieved {0} columns.",   fieldCount);
    for (int i = 0; i < fieldCount; i++)
        Console.WriteLine(values[i]);
}

Using MySqlDataReader.FieldCount will allow you to retrieve the number of columns in the row you've queried.

Answer 5

Or use the sys.columns

--SQL 2005
SELECT  *
FROM    sys.columns
WHERE   OBJECT_NAME(object_id) = 'spt_values'
-- returns 6 rows = 6 columns

--SQL 2000
SELECT  *
FROM    syscolumns
WHERE   OBJECT_NAME(id) = 'spt_values'
-- returns 6 rows = 6 columns

SELECT  *
FROM    dbo.spt_values
    -- 6 columns indeed

Answer 6

SELECT COUNT(COLUMN_NAME) 
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE 
    TABLE_CATALOG = 'Database name' 
    AND TABLE_SCHEMA = 'dbo' 
    AND TABLE_NAME = 'table name'