Translate NOT NULL violation to the specific exception

Raise `ActiveRecord::NotNullViolation` when a record cannot be inserted
or updated because it would violate a not null constraint.

4 files changed, 13 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index b600fa5785..0e4bc1afcb 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -734,6 +734,8 @@ module ActiveRecord
 
         # See https://dev.mysql.com/doc/refman/5.7/en/error-messages-server.html
         ER_DUP_ENTRY            = 1062
+        ER_NOT_NULL_VIOLATION   = 1048
+        ER_DO_NOT_HAVE_DEFAULT  = 1364
         ER_NO_REFERENCED_ROW_2  = 1452
         ER_DATA_TOO_LONG        = 1406
         ER_LOCK_DEADLOCK        = 1213
@@ -756,6 +758,8 @@ module ActiveRecord
             end
           when ER_DATA_TOO_LONG
             ValueTooLong.new(message)
+          when ER_NOT_NULL_VIOLATION, ER_DO_NOT_HAVE_DEFAULT
+            NotNullViolation.new(message)
           when ER_LOCK_DEADLOCK
             Deadlocked.new(message)
           else
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 263456a6a3..5262141995 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -408,6 +408,7 @@ module ActiveRecord
 
         # See http://www.postgresql.org/docs/current/static/errcodes-appendix.html
         VALUE_LIMIT_VIOLATION = "22001"
+        NOT_NULL_VIOLATION    = "23502"
         FOREIGN_KEY_VIOLATION = "23503"
         UNIQUE_VIOLATION      = "23505"
         SERIALIZATION_FAILURE = "40001"
@@ -423,6 +424,8 @@ module ActiveRecord
             InvalidForeignKey.new(message)
           when VALUE_LIMIT_VIOLATION
             ValueTooLong.new(message)
+          when NOT_NULL_VIOLATION
+            NotNullViolation.new(message)
           when SERIALIZATION_FAILURE
             SerializationFailure.new(message)
           when DEADLOCK_DETECTED
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index eeaf739011..a7c4a2cd86 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -530,6 +530,8 @@ module ActiveRecord
           #   column *column_name* is not unique
           when /column(s)? .* (is|are) not unique/, /UNIQUE constraint failed: .*/
             RecordNotUnique.new(message)
+          when /.* may not be NULL/, /NOT NULL constraint failed: .*/
+            NotNullViolation.new(message)
           else
             super
           end
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 7c8be37326..3c0b7e98bd 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -151,6 +151,10 @@ module ActiveRecord
       end
   end
 
+  # Raised when a record cannot be inserted or updated because it would violate a not null constraint.
+  class NotNullViolation < StatementInvalid
+  end
+
   # Raised when a record cannot be inserted or updated because a value too long for a column type.
   class ValueTooLong < StatementInvalid
   end