Returns information about fieldName.
fileName - the name of an open database file (local or remote).
fieldName - the name of a field in the specified database file.
Important  See Design functions for information about literal text parameters.
Data type returned 
Originated in 
FileMaker Pro 6.0 or earlier
Field names must be in the format tablename::fieldname to specify a field that exists in a table different from the current table. The result has four values separated by spaces:
The second value is the field type: text, number, date, time, timestamp, or container.
FieldType(“Customers”;“Phone Number”) returns Standard Text Unindexed 3 when, in the Customers database file, the Phone Number field is defined as a text field that repeats a maximum of three times and the storage options are left unchanged. (Most fields are indexed when a find is performed in that field.)
FieldType(“Customers”;“Current Balance”) returns StoredCalc Number Indexed 1 when, in the Customers database file, the Current Balance field is defined as a stored, numeric calculation field that is indexed.
FieldType(“Customers”;“Today’s Date”) returns Global Date Unindexed 1 when, in the Customers database file, the Today’s Date field is defined as a global field of type date. Global fields are never indexed.
FieldType(“Customers”;”Statement”) returns External(Secure) Container Unindexed 1 when, in the Customers database file, the Statement field is defined as a container field that stores data externally using secure storage. Container fields cannot be indexed.
Related topics 
Functions reference (category list)
Functions reference (alphabetical list)
About formulas
About functions
Defining calculation fields
Using operators in formulas