From f6d162c983f4773b38debe46d8e4f5bbc3027a8f Mon Sep 17 00:00:00 2001
From: guzman-raphael <raphael.h.guzman@gmail.com>
Date: Tue, 19 May 2020 09:21:03 -0500
Subject: [PATCH 1/2] Add check to verify that blobs are not sparse (for now).

---
 +dj/Relvar.m | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/+dj/Relvar.m b/+dj/Relvar.m
index 1ca2eceb..5dd6cf2e 100755
--- a/+dj/Relvar.m
+++ b/+dj/Relvar.m
@@ -249,6 +249,7 @@ function insert(self, tuples, command)
                             blobs{end+1} = char(v);  %#ok<AGROW>
                         end
                     elseif header.attributes(i).isBlob
+                        assert(~issparse(v), 'Sparse blobs not currently supported');
                         valueStr = sprintf('%s"{M}",', valueStr);
                         blobs{end+1} = v;    %#ok<AGROW>
                     else
@@ -363,6 +364,7 @@ function update(self, attrname, value)
                     valueStr = '"{S}"';
                     value = {char(value)};
                 case header.attributes(ix).isBlob
+                    assert(~issparse(value), 'Sparse blobs not currently supported');
                     valueStr = '"{M}"';
                     value = {value};
                 case header.attributes(ix).isNumeric

From d842885e1c5eb6fe8f9f5841ba7a61197808d174 Mon Sep 17 00:00:00 2001
From: guzman-raphael <raphael.h.guzman@gmail.com>
Date: Tue, 19 May 2020 09:45:58 -0500
Subject: [PATCH 2/2] Update error message.

---
 +dj/Relvar.m | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/+dj/Relvar.m b/+dj/Relvar.m
index 5dd6cf2e..40f2fc4b 100755
--- a/+dj/Relvar.m
+++ b/+dj/Relvar.m
@@ -249,7 +249,10 @@ function insert(self, tuples, command)
                             blobs{end+1} = char(v);  %#ok<AGROW>
                         end
                     elseif header.attributes(i).isBlob
-                        assert(~issparse(v), 'Sparse blobs not currently supported');
+                        assert(~issparse(v), ...
+                            'DataJoint:DataType:Mismatch', ...
+                            'The field `%s` must not be a sparse blob', ...
+                            header.attributes(i).name);
                         valueStr = sprintf('%s"{M}",', valueStr);
                         blobs{end+1} = v;    %#ok<AGROW>
                     else
@@ -364,7 +367,10 @@ function update(self, attrname, value)
                     valueStr = '"{S}"';
                     value = {char(value)};
                 case header.attributes(ix).isBlob
-                    assert(~issparse(value), 'Sparse blobs not currently supported');
+                    assert(~issparse(value), ...
+                        'DataJoint:DataType:Mismatch', ...
+                        'The field `%s` must not be a sparse blob', ...
+                        attrname);
                     valueStr = '"{M}"';
                     value = {value};
                 case header.attributes(ix).isNumeric