How to store complex strings in the database?

I am learning Elixir so please bear with me. I am trying to figure out how to store complex string into the database. Using an SVG file as an example (because it has a good mix of characters for testing), what is the best way to store it into the database (Postgres/mnesia etc.). I tried converting it into base64, using sigils etc. to no avail. All of them will find some fault with certain characters within the complex string. Is there another way to do this? Thanks in advance.

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Hey @carter. Any time you have some sort of issue you’re running into, it helps if you can provide an example piece of data, as well as the code you tried to run, and the errors you ran into. It’s hard to help without this info.

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Thank you for the reply. Here’s some examples of what I have tried and the error I get.

Base.encode64("<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"> <svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" width="500px" height="500px" viewBox="0 0 500 500" enable-background="new 0 0 500 500" xml:space="preserve"> <path fill="none" stroke="#010101" stroke-width="0.5" stroke-linecap="round" stroke-linejoin="round" d="M274.767,96.803" /> <path fill="none" stroke="#010101" stroke-width="0.5" stroke-linecap="round" stroke-linejoin="round" d="M280.375,91.197" /> <path fill="none" stroke="#010101" stroke-width="0.5" stroke-linecap="round" stroke-linejoin="round" d="M280.375,91.197" /> <path fill="#EF3D25" d="M209.648,128.194c-0.841,0.113-17.177,2.8-19.153,11.005c-1.573,6.537,5.536,19.816,5.536,24.399 c4.862,0.901,9.493-2.008,13.98-3.388c4.489-1.379-3.46-11.632-2.862-15.131c0.598-3.499,2.973-1.707,4.496-3.207 c1.524-1.5,8.452-5.854,6.355-11.681C217.332,128.335,214.732,127.515,209.648,128.194z" /> <path fill="none" stroke="#010101" stroke-width="1.5" stroke-linecap="round" stroke-miterlimit="10" d="M213.15,141.376 c0,0-9.433,3.782-10.522,6.972" /> <path fill="none" stroke="#010101" stroke-width="1.5" stroke-linecap="round" stroke-miterlimit="10" d="M197.846,131.557 c3.877,0.45,8.595-0.095,10.682,1.903" /> </svg>")

** (SyntaxError) iex:1:103: keyword argument must be followed by space after: http:

Here’s another

~s(<?xml version="1.0" encoding="UTF-8" standalone="no"?> <svg xmlns:dc="http://purl.org/dc/elements/1.1/"     xmlns:cc="http://creativecommons.org/ns#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"     xmlns:svg="http://www.w3.org/2000/svg" xmlns="http://www.w3.org/2000/svg"     xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"     xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" id="svg" version="1.1" width="48" height="48"     viewBox="0 0 48 48" sodipodi:docname="Amazon DynamoDB.svg" inkscape:version="0.92.5 (2060ec1f9f, 2020-04-08)">     <metadata id="metadata10">         <rdf:RDF>             <cc:Work rdf:about="">                 <dc:format>image/svg+xml</dc:format>                 <dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage" />             </cc:Work>         </rdf:RDF>     </metadata>     <defs id="defs8" />     <sodipodi:namedview pagecolor="#ffffff" bordercolor="#666666" borderopacity="1" objecttolerance="10"         gridtolerance="10" guidetolerance="10" inkscape:pageopacity="0" inkscape:pageshadow="2"         inkscape:window-width="3696" inkscape:window-height="2032" id="namedview6" showgrid="false" inkscape:zoom="0.59"         inkscape:cx="200" inkscape:cy="200" inkscape:window-x="144" inkscape:window-y="54" inkscape:window-maximized="1"         inkscape:current-layer="svg" />     <g id="svgg" transform="scale(0.12)">         <path id="path0"             d="M 0,200 V 400 H 200 400 V 200 0 H 200 0 v 200 m 389.6,0 V 390.4 H 199.6 9.6 V 200 9.6 h 190 190 V 200 M 173.6,61 c 0,0.51 -1.044,0.6 -7,0.6 -4.4,0 -7,0.149 -7,0.4 0,0.24 -1.6,0.4 -4,0.4 -3.289,0 -4,0.107 -4,0.6 0,0.489 -0.667,0.6 -3.6,0.6 -2.133,0 -3.6,0.163 -3.6,0.4 0,0.222 -1.067,0.4 -2.4,0.4 -1.867,0 -2.4,0.133 -2.4,0.6 0,0.453 -0.489,0.6 -2,0.6 -1.1,0 -2,0.18 -1.6,-0.6 -0.88,0 -1.6,-0.18 -1.6,-0.4 0,-0.22 -0.45,-0.4 -1,-0.4 -0.622,0 -1,-0.227 -1,-0.6 0,-0.467 -0.533,-0.6 -2.4,-0.6 -2.265,0 -2.4,0.054 -2.4,0.957"             inkscape:connector-curvature="0" style="fill:#000000;fill-rule:evenodd;stroke:none" />         <path id="path1" d="" inkscape:connector-curvature="0" style="fill:#ffffff;fill-rule:evenodd;stroke:none" />     </g> </svg>)

** (SyntaxError) iex:1:762: keyword argument must be followed by space after: http:

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I would highly recommend storing this SVG information in an actual file, and then calling File.read!("path/to/file.svg"). Giant string literals like this are often a pain to deal with.

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I second Ben’s recommendation to read from file.

Otherwise, you could try heredocs… (as long as string doesn’t contain and new line followed by whitespaces and """)

string = """
<?xml ..>
"""
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Thank you for your replies. The real challenge is around storing complex strings and not really SVG per se. I am using SVG as an example. Let me try another scenario. Let’s say I create a blog and allow users to create any content they like. Let’s say a user decides to embed some codes with his article. It would come with all kinds of characters that I cannot control. What is the best way to process and store to the DB a complex document like that? Heredocs is possible, but it does comes with the contstraint mentioned above. Is there a sure-fire way to handle the complex string without worrying about the content, new line, whitespace and any other surprises?

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What is the tool that you use to write to the database ?

Because once you have your svg string in a variable, you should not have problems with special characters unless you are bulding raw sql like this: "INSERT INTO t VALUES('#{svg}');". This will not work.

But if you use a tool like Ecto, then your variable should fit into a text or binary column.

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I’m not arguing the issue of just storing any random textual content in a Postgres text column?

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