Problem when line feed code is mixed when csv in import into varchar column with AWS Aurora.

[Environment]

• AWS Aurora or Mysql

[Problem]

• When csv file is imported to string column,If the criteria are enclosed in single quotes, will not produce the desired result.

where target_column = '31000000000';

• If the criteria are not enclosed in single quotes,ok.

where target_column = 31000000000;

[Cause]

• If you import a csv file without double quotes in the loader,Imports up to unnecessary line feed codes.
• Line feed code is usually invisible in database.It is necessary to look in hexadecimal.

value	memo	hex(value)
31000000000	csv	33313030303030303030300D
31000000000	DML	3331303030303030303030

’0D’ is Line feed code of UTF-8.

[point]rule of mysql.

• For conditional expression [string = number],Compare strings on left side as decimal numbers.line feed code is invalid.

• For conditional expression [string = string],The character strings on the left side are compared as they are.line feed code is valid.

[How to]

• To see the line feed code, convert it to hexadecimal.my case is LF.In hexadecimal, it is “0d”.
• This DML deletes only the line feed code.

update target_table_name set target_column_name = TRIM( UNHEX('0D') FROM target_column_name );