System functions return system information.
The following system functions are available:
Some of the system functions are implemented in SQL Anywhere as stored procedures.
The db_id, db_name, and datalength functions are implemented as built-in functions.
The implemented system functions are described in the following table.
|col_length( table-name, column-name )||Returns the defined length of column|
|col_name( table-id, column-id [, database-id ] )||Returns the column name|
|datalength( expression )||Returns the length of the expression, in bytes|
|db_id( [ database-name ] )||Returns the database ID number|
|db_name( [ database-id ] )||Returns the database name|
|index_col ( table-name, index-id, key_# [, userid ] )||Returns the name of the indexed column|
|object_id ( object-name )||Returns the object ID|
|object_name ( object-id [, database-id ] )||Returns the object name|
|suser_id( [ user-name ] )||Returns an integer user identification number|
|suser_name( [ user-id ] )||Returns the user ID|
|tsequal ( timestamp, timestamp2 )||In SQL Anywhere, tsequal compares timestamp values (truncated to milliseconds) to prevent an update on a row that has been modified since it was selected. When timestamps are different, false (0) is returned. See Using tsequal for updates. The use of tsequal is deprecated.|
|user_id( [ user-name ] )||Returns an integer user identification number. This does not return the SQL Anywhere user ID.|
|user_name( [user-id ] )||Returns the user ID|