How to print Core Data debug values?

Question

How can I print the values being sent to the sqlite database while using Core Data SQL Debug?

Using the "-com.apple.CoreData.SQLDebug 1" in my "Arguments Passed on Launch" debug options prints the SQL structure just fine

(you can check see how to use this here: XCode4 and Core Data: How to enable SQL Debugging)

But the problem is that the NSLog printed is something like UPDATE ZTABLE SET ZCOLUMN = ? WHERE ZID = ? and it does not help at all if you are trying to see what is the full SQL statement and/or data being sent to the database.

Answer 1

Open "Product -> Scheme -> Edit Scheme..." in Xcode and add to "Arguments Passed on Launch":

-com.apple.CoreData.SQLDebug 3
-com.apple.CoreData.Logging.stderr 1 

(The second launch argument is needed for Core Data debugging on iOS 10/macOS 10.12 or later, see com.apple.CoreData.SQLDebug not working for more information.)

The you'll see all the values that the SQL statements are bound to. Example output:

test56[1588:c07] CoreData: sql: BEGIN EXCLUSIVE
test56[1588:c07] CoreData: sql: INSERT INTO ZEVENT(Z_PK, Z_ENT, Z_OPT, ZTIMESTAMP) VALUES(?, ?, ?, ?)
test56[1588:c07] CoreData: details: SQLite bind[0] = (int64)13
test56[1588:c07] CoreData: details: SQLite bind[1] = (int64)1
test56[1588:c07] CoreData: details: SQLite bind[2] = (int64)1
test56[1588:c07] CoreData: details: SQLite bind[3] = "368650709.435904"
test56[1588:c07] CoreData: sql: COMMIT

Answer 2

If you are using Xcode 8, you will need to also need to add additional argument

-com.apple.CoreData.Logging.stderr 1