截取出来的字符可能有空格需要去掉空格

好的，我修改一下存储过程，加入去除空格的功能。以下是修改过的存储过程。

DELIMITER $$
CREATE PROCEDURE insert_data_from_txt(IN file_name VARCHAR(255))
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE line VARCHAR(255);
    DECLARE col1 VARCHAR(8);
    DECLARE col2 VARCHAR(5);
    DECLARE col3 VARCHAR(6);
    DECLARE file_cursor CURSOR FOR SELECT * FROM INFORMATION_SCHEMA.FILES WHERE FILE_NAME = file_name;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    
    OPEN file_cursor;
    FETCH file_cursor INTO line;
    
    WHILE NOT done DO
        SET col1 = TRIM(SUBSTRING(line, 1, 8));
        SET col2 = TRIM(SUBSTRING(line, 9, 5));
        SET col3 = TRIM(SUBSTRING(line, 14, 6));
        
        INSERT INTO your_table_name (column1, column2, column3) VALUES (col1, col2, col3);
        
        FETCH file_cursor INTO line;
    END WHILE;
    
    CLOSE file_cursor;
END$$
DELIMITER ;

我在每个字段的赋值语句中加入了`TRIM()`函数，用于去除每个字段的空格。现在存储过程会在读取txt文件并插入数据之前先去除每个字段的空格。