Query returns basic statistics of numbers of columns in a database.
Query
select [columns], 
    [tables], 
    CONVERT(DECIMAL(10,2),1.0*[columns]/[tables]) as average_column_count
from (
    select count(*) [columns],
           count(distinct schema_name(tab.schema_id) + tab.name) as [tables]
       from sys.tables as tab
            inner join sys.columns as col
                on tab.object_id = col.object_id
) q
Columns
- columns - total number of columns in a database
- tables - number of tables in a database
- average_column_count - average number of columns in a table in a database
Rows
- Query returns just one row
Sample results

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Piotr Kononow
                                                                        Piotr Kononow
                                 SQL Server
                                                                SQL Server
                                 Azure SQL Database
                                                                                                Azure SQL Database
                                             Oracle database
                                                                                                Oracle database
                                             Snowflake
                                                                                                Snowflake
                                             Amazon Redshift
                                                                                                Amazon Redshift
                                             IBM Db2
                                                                                                IBM Db2
                                             Teradata
                                                                                                Teradata
                                             Vertica
                                                                                                Vertica
                                             PostgreSQL
                                                                                                PostgreSQL
                                             MySQL
                                                                                                MySQL
                                             MariaDB
                                                                                                MariaDB