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mysqlstringutf-8character-encoding

How to fix double-encoded UTF8 characters (in an utf-8 table)

A previous LOAD DATA INFILE was run under the assumption that the CSV file is latin1-encoded. During this import the multibyte characters were interpreted as two single character and then encoded using utf-8 (again).

This double-encoding created anomalies like ñ instead of ñ.

How to correct these strings?

Solution

  • The following MySQL function will return the correct utf8 string after double-encoding:

    CONVERT(CAST(CONVERT(field USING latin1) AS BINARY) USING utf8)

    It can be used with an UPDATE statement to correct the fields:

    UPDATE tablename SET
    field = CONVERT(CAST(CONVERT(field USING latin1) AS BINARY) USING utf8);