TableIDs
Purpose 
Returns a list of all table IDs in fileName, separated by carriage returns.
Format 
TableIDs(fileName)
Parameters 
fileName - the name of an open database file (local or remote).
Important  See Design functions for information about literal text parameters.
Data type returned 
text
Originated in 
FileMaker Pro 6.0 or earlier
Description 
Each table ID is unique. Also, the ID is independent of when you create each table: the first table could have the smallest, middle, or largest value.
If no parameter is specified for fileName, FileMaker returns results for the current file.
Examples 
TableIDs(“University Database”) returns
1065089
1065090
for the University Database database file if two tables have been defined for the file.
Related topics 
Functions reference (category list)
Functions reference (alphabetical list)
About formulas
About functions
Defining calculation fields
Using operators in formulas