如何修复双重编码的UTF8字符（在utf-8表中）
问题描述：
上一个 LOAD DATA INFILE 是在假设CSV文件 latin1 -encoded的情况下运行的。在此导入过程中，多字节字符被解释为两个单字符，然后再次使用utf-8编码。
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).
这种双重编码创建了异常，如
This double-encoding created anomalies like ñ instead of ñ.
如何更正这些字符串？
答
以下MySQL函数将在双重编码后返回正确的utf8字符串：
The following MySQL function will return the correct utf8 string after double-encoding:
CONVERT(CAST(CONVERT(field USING latin1) AS BINARY) USING utf8)
它可以与 UPDATE 语句一起使用以更正字段：
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);