如何导出断线＆＃39; \ n＆＃39;在使用MySQL INTO OUTFILE的文件中

Question

我尝试使用MySQL导出sql文件。我使用此方法是因为我想导入具有LOAD DATA功能的文件。并且文件名必须以dinamically方式生成。我将执行通过命令行生成的文件。

这是剧本：

SET @filename = 'C:/icl/myfile.CSV';

SET @str = CONCAT('LOAD DATA INFILE ',@filename);
SET @str = CONCAT(@str,' INTO TABLE icl_process_data.filecontent LINES TERMINATED BY ''\n''');

SELECT @str INTO OUTFILE 'C:/icl/tmp_script.sql';

结果如下：

LOAD DATA INFILE C:/icl/myfile.CSV INTO TABLE icl_process_data.filecontent LINES TERMINATED BY '\'

我不知道为什么断线的结果＆＃39; \ n＆＃39;是＆＃39; \＃39;。我怎么能解决这个问题？

Answer 1

这是逃避序列的问题，有几种方法可以做到这一点。我选择将起始单引号放在第一路的末尾附近的外部双引号内（在concat中有3个块）。

单引号作为第二种方式（在concat中有2个块）：

SET @filename = 'C:/icl/myfile.CSV';
-- C:/icl/myfile.CSV

SET @str = CONCAT('LOAD DATA INFILE ',@filename);
-- LOAD DATA INFILE C:/icl/myfile.CSV

-- First way is below (with the result being the line after it if you ignore the `-- ` at the beginning):
SET @str = CONCAT(@str," INTO TABLE icl_process_data.filecontent LINES TERMINATED BY '","\\n'");
-- LOAD DATA INFILE C:/icl/myfile.CSV INTO TABLE icl_process_data.filecontent LINES TERMINATED BY '\n'

-- Second way is below (with the result being the line after it if you ignore the `-- ` at the beginning):
SET @str = CONCAT('LOAD DATA INFILE ',@filename);
SET @str = CONCAT(@str,' INTO TABLE icl_process_data.filecontent LINES TERMINATED BY \'\\n\'');
-- LOAD DATA INFILE C:/icl/myfile.CSV INTO TABLE icl_process_data.filecontent LINES TERMINATED BY '\n'

来自String Literals上的mysql手册页：