fix #244 - error when querying BLOB data

Author: amochin

src/DatabaseLibrary/query.py

@@ -827,7 +827,11 @@ def _log_query_results(self, col_names, result_rows, log_head: Optional[int] = N
             msg += f"<tr{row_style}>"
             msg += f'<th scope="row" style="color:{row_index_text_color}; background-color: {row_index_background_color};{cell_border_and_align}">{i}</th>'
             for cell in row:
-                msg += f'<td style="{cell_border_and_align}">{cell}</td>'
+                try:
+                    cell_string = str(cell)
+                except TypeError as e:
+                    cell_string = f"Unable printing the value: {e}"
+                msg += f'<td style="{cell_border_and_align}">{cell_string}</td>'
             msg += "</tr>"
         msg += "</table>"
         if table_truncated:

test/tests/custom_db_tests/oracle_blob.robot

@@ -0,0 +1,29 @@
+*** Settings ***
+Documentation       Tests for querying a table with BLOB data type.
+...                 The data type naming is DB specific, these tests are designed for Oracle DB only.
+
+Resource            ../../resources/common.resource
+
+Suite Setup         Connect To DB
+Suite Teardown      Disconnect From Database
+Test Setup          Execute Sql String
+...                     CREATE TABLE blob_table (id integer not null unique, data blob)
+Test Teardown       Execute Sql String    DROP TABLE blob_table
+
+
+*** Variables ***
+${DB_MODULE}            oracledb
+${DB_HOST}              127.0.0.1
+${DB_PORT}              1521
+${DB_PASS}              pass
+${DB_USER}              db_user
+${DB_NAME}              db
+${ORACLE_LIB_DIR}       ${EMPTY}
+
+
+*** Test Cases ***
+Blob Data Type - Logging Results Causes No Error
+    [Documentation]    See https://github.com/MarketSquare/Robotframework-Database-Library/issues/244
+    ${binary_data}=    Evaluate    b'abc'
+    Execute Sql String    INSERT INTO blob_table VALUES(1, '${binary_data}')
+    ${result}=    Query    SELECT data FROM blob_table WHERE id=1