• Azure Functions SQL Extension or Extension Bundle Version:
  Azure Functions Core Tools
  Core Tools Version: 4.0.7030 Commit hash: N/A +bb4c949899cd5659d6bfe8b92cc923453a2e8f88 (64-bit)
  Function Runtime Version: 4.1037023568
• Is this a deployed or local function: Local and Deployed
• What type of Database are you using? Microsoft SQL Azure (RTM) - 12.0.2000.8 Apr 9 2025 07:13:50 Copyright (C) 2024 Microsoft Corporation 5

Steps to Reproduce:

1. CREATE TABLE BinaryData (BinaryColumn binary(8))
2. Attempt to send the following JSON string to the output binding for the above table: '{"BinaryColumn":"//////////8="}'
3. This should result in the binary value 0xFFFFFFFFFFFFFFFF being inserted into the table. Instead an error is returned:

Base64 encoded string cannot be converted to binary value. Binary data would be truncated.

This only occurs when a "/" character exists in the BASE64 string. This is because the output binding framework tries to run the following command, escaping "/" characters in the whole JSON object.

SELECT * FROM OPENJSON(REPLACE(@rowData, N'/', N'\/')) WITH ([BinaryColumn] binary(8))

Manually running the above SQL, but doubling the length to binary(16) avoids the error.