Update column from Base64 to string (natively in SQL)












1















I've been trying to figure this out for two days now and would really appreciate some help. I've imported data from a csv where one field contained html data encoded in base64.



The idea is to loop over every row and run FROM_BASE64 on it.



How do I structure a query that:




  1. Loops over all lines

  2. Calls FRON_BASE64 for each line

  3. Runs UPDATE (or similar functionality) on that same row and column


Context: I'm running MariaDB (MySQL equivalent).



Thanks for any help!










share|improve this question





























    1















    I've been trying to figure this out for two days now and would really appreciate some help. I've imported data from a csv where one field contained html data encoded in base64.



    The idea is to loop over every row and run FROM_BASE64 on it.



    How do I structure a query that:




    1. Loops over all lines

    2. Calls FRON_BASE64 for each line

    3. Runs UPDATE (or similar functionality) on that same row and column


    Context: I'm running MariaDB (MySQL equivalent).



    Thanks for any help!










    share|improve this question



























      1












      1








      1








      I've been trying to figure this out for two days now and would really appreciate some help. I've imported data from a csv where one field contained html data encoded in base64.



      The idea is to loop over every row and run FROM_BASE64 on it.



      How do I structure a query that:




      1. Loops over all lines

      2. Calls FRON_BASE64 for each line

      3. Runs UPDATE (or similar functionality) on that same row and column


      Context: I'm running MariaDB (MySQL equivalent).



      Thanks for any help!










      share|improve this question
















      I've been trying to figure this out for two days now and would really appreciate some help. I've imported data from a csv where one field contained html data encoded in base64.



      The idea is to loop over every row and run FROM_BASE64 on it.



      How do I structure a query that:




      1. Loops over all lines

      2. Calls FRON_BASE64 for each line

      3. Runs UPDATE (or similar functionality) on that same row and column


      Context: I'm running MariaDB (MySQL equivalent).



      Thanks for any help!







      mysql sql mariadb






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 19 '18 at 18:24









      Bill Karwin

      377k63515670




      377k63515670










      asked Nov 19 '18 at 18:11









      MentorMentor

      472213




      472213
























          1 Answer
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          1














          Typically base64 would be used for binary data. You probably shouldn't store the decoded data in the same column as the base64-coded string. If necessary you should ALTER TABLE to add a new column that is VARBINARY or BLOB type, to hold the binary data.



          ALTER TABLE MyTable ADD COLUMN BinaryField BLOB;


          You can then fill that column with an UPDATE statement:



          UPDATE MyTable SET BinaryField = FROM_BASE64(EncodedField);





          share|improve this answer
























          • Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

            – Mentor
            Nov 19 '18 at 18:37













          • Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

            – Mentor
            Nov 19 '18 at 18:47











          • You might want to learn about character sets.

            – Bill Karwin
            Nov 19 '18 at 19:25











          • The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

            – Rick James
            Nov 20 '18 at 3:44











          • @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

            – Mentor
            Nov 21 '18 at 10:22











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          1 Answer
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          1 Answer
          1






          active

          oldest

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          active

          oldest

          votes






          active

          oldest

          votes









          1














          Typically base64 would be used for binary data. You probably shouldn't store the decoded data in the same column as the base64-coded string. If necessary you should ALTER TABLE to add a new column that is VARBINARY or BLOB type, to hold the binary data.



          ALTER TABLE MyTable ADD COLUMN BinaryField BLOB;


          You can then fill that column with an UPDATE statement:



          UPDATE MyTable SET BinaryField = FROM_BASE64(EncodedField);





          share|improve this answer
























          • Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

            – Mentor
            Nov 19 '18 at 18:37













          • Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

            – Mentor
            Nov 19 '18 at 18:47











          • You might want to learn about character sets.

            – Bill Karwin
            Nov 19 '18 at 19:25











          • The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

            – Rick James
            Nov 20 '18 at 3:44











          • @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

            – Mentor
            Nov 21 '18 at 10:22
















          1














          Typically base64 would be used for binary data. You probably shouldn't store the decoded data in the same column as the base64-coded string. If necessary you should ALTER TABLE to add a new column that is VARBINARY or BLOB type, to hold the binary data.



          ALTER TABLE MyTable ADD COLUMN BinaryField BLOB;


          You can then fill that column with an UPDATE statement:



          UPDATE MyTable SET BinaryField = FROM_BASE64(EncodedField);





          share|improve this answer
























          • Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

            – Mentor
            Nov 19 '18 at 18:37













          • Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

            – Mentor
            Nov 19 '18 at 18:47











          • You might want to learn about character sets.

            – Bill Karwin
            Nov 19 '18 at 19:25











          • The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

            – Rick James
            Nov 20 '18 at 3:44











          • @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

            – Mentor
            Nov 21 '18 at 10:22














          1












          1








          1







          Typically base64 would be used for binary data. You probably shouldn't store the decoded data in the same column as the base64-coded string. If necessary you should ALTER TABLE to add a new column that is VARBINARY or BLOB type, to hold the binary data.



          ALTER TABLE MyTable ADD COLUMN BinaryField BLOB;


          You can then fill that column with an UPDATE statement:



          UPDATE MyTable SET BinaryField = FROM_BASE64(EncodedField);





          share|improve this answer













          Typically base64 would be used for binary data. You probably shouldn't store the decoded data in the same column as the base64-coded string. If necessary you should ALTER TABLE to add a new column that is VARBINARY or BLOB type, to hold the binary data.



          ALTER TABLE MyTable ADD COLUMN BinaryField BLOB;


          You can then fill that column with an UPDATE statement:



          UPDATE MyTable SET BinaryField = FROM_BASE64(EncodedField);






          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Nov 19 '18 at 18:27









          Bill KarwinBill Karwin

          377k63515670




          377k63515670













          • Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

            – Mentor
            Nov 19 '18 at 18:37













          • Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

            – Mentor
            Nov 19 '18 at 18:47











          • You might want to learn about character sets.

            – Bill Karwin
            Nov 19 '18 at 19:25











          • The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

            – Rick James
            Nov 20 '18 at 3:44











          • @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

            – Mentor
            Nov 21 '18 at 10:22



















          • Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

            – Mentor
            Nov 19 '18 at 18:37













          • Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

            – Mentor
            Nov 19 '18 at 18:47











          • You might want to learn about character sets.

            – Bill Karwin
            Nov 19 '18 at 19:25











          • The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

            – Rick James
            Nov 20 '18 at 3:44











          • @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

            – Mentor
            Nov 21 '18 at 10:22

















          Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

          – Mentor
          Nov 19 '18 at 18:37







          Thank you for that! The current data type of the column is string (I'm importing into a table I didn't make and shouldn't alter). Would I cause issues with UPDATE MyTable SET BinaryField = FROM_BASE64(Binary Field) ;. In case I was unclear, I don't need the original Base64 string.

          – Mentor
          Nov 19 '18 at 18:37















          Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

          – Mentor
          Nov 19 '18 at 18:47





          Figured it out. update thetable set thecolumn = FROM_BASE64(thecolumn) did the trick. This was simpler than I anticipated.

          – Mentor
          Nov 19 '18 at 18:47













          You might want to learn about character sets.

          – Bill Karwin
          Nov 19 '18 at 19:25





          You might want to learn about character sets.

          – Bill Karwin
          Nov 19 '18 at 19:25













          The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

          – Rick James
          Nov 20 '18 at 3:44





          The Base64 column should be TEXT CHARACTER SET ascii COLLATE ascii_bin. (There are other options, but this is the most logical.)

          – Rick James
          Nov 20 '18 at 3:44













          @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

          – Mentor
          Nov 21 '18 at 10:22





          @RickJames, like I mentioned in my comment, the data was being imported into a database belonging to an existing codebase. The only reason the string was base64 encoded was to make it easier to store html in a csv file without causing syntax issues.

          – Mentor
          Nov 21 '18 at 10:22




















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