Querying non-printable characters from the database

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1

I want to save DPL labels, similar to ZPL, in MSSQL database for future retrieval and printing. My problem is the DPL string contains non-printable characters that are being stripped out of my query results, for example the STX delimiter (start of line) \x02.

I assume the characters are being stored properly based on copying the string from management studio and pasting into notepad++ shows the missing characters

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However when I query the label string and print the results in ignition the STX delimiter is gone, however the end of line character is still present.

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Any help is greatly appreciated!

2

Is this any help?

string = "\02n\r\n\02M0592\r\n\02O0220\r\n"
charArray = [c for c in string]
print(charArray)

# Returns:
# ['\x02', 'n', '\r', '\n', '\x02', 'M', '0', '5', '9', '2', '\r', '\n', '\x02', 'O', '0', '2', '2', '0', '\r', '\n']

STX is 0x02.

Try it in the script console.

3

Many things won't print visibly even though they are there. If in doubt, especially when charsets are involved, use byte arrays and blob columns.

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4

Yeah I noticed that. When I read the file from disk then print the results the characters in question aren’t visible, but they are still there. When I query them from the database and print them they just aren’t there period, but they are in the database.

I think your suggestion of reading the label file as a byte array and storing it that way might be the way to go.