SQL Server/T-SQL Tutorial/System Functions/COL LENGTH

COL_LENGTH takes two arguments, the table name and the column name.

What it returns is the defined length of the particular column.
5>
6> CREATE TABLE publishers(
7>    pub_id         char(4)           NOT NULL,
8>    pub_name       varchar(40)           NULL,
9>    city           varchar(20)           NULL,
10>    state          char(2)               NULL,
11>    country        varchar(30)           NULL DEFAULT("USA")
12> )
13> GO
1>
2>
3> insert publishers values("1", "Publisher A", "Vancouver",  "MA", "USA")
4> insert publishers values("2", "Publisher B", "Washington", "DC", "USA")
5> insert publishers values("3", "Publisher C", "Berkeley",   "CA", "USA")
6> insert publishers values("4", "Publisher D", "New York",   "NY", "USA")
7> insert publishers values("5", "Publisher E", "Chicago",    "IL", "USA")
8> insert publishers values("6", "Publisher F", "Dallas",     "TX", "USA")
9> insert publishers values("7", "Publisher G", "Vancouver",  "BC", "Canada")
10> insert publishers values("8", "Publisher H", "Paris",      NULL, "France")
11> GO
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>      SELECT COL_LENGTH("publishers", "pub_id")
2> GO
------
     4
(1 rows affected)
1>
2> drop table publishers;
3> GO
1>