MySQL 如何处理包含空值的表导出到CSV文件中

如果我们从包含NULL值的表中导出数据，MySQL会在CSV文件中为具有NULL值的记录中存储\N。可以用以下示例说明：

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示例

假设我们想要导出’tudent_info’表的值，包含以下数据 –

mysql> Select * from Student_info;
+------+---------+------------+------------+
| id   | Name    | Address    | Subject    |
+------+---------+------------+------------+
| 101  | YashPal | Amritsar   | History    |
| 105  | Gaurav  | Chandigarh | Literature |
| 125  | Raman   | Shimla     | Computers  |
| 130  | Ram     | Jhansi     | Computers  |
| 132  | Shyam   | Chandigarh | Economics  |
| 133  | Mohan   | Delhi      | Computers  |
| 150  | Saurabh | NULL       | Literature |
+------+---------+------------+------------+
7 rows in set (0.00 sec)

我们可以看到结果在地址字段中有一个NULL值，其中id为150。现在以下查询将导出此表中的数据到Student_27.CSV中 –

mysql> Select * from Student_info INTO OUTFILE 'C:/mysql/bin/mysql-files/student_27.csv' FIELDS TERMINATED BY ',';
Query OK, 7 rows affected (0.02 sec)

上述查询已在Student_27.CSV文件中存储以下值 –

101   YashPal   Amritsar     History
105   Gaurav    Chandigarh   Literature
125   Raman     Shimla       Computers
130   Ram       Jhansi       Computers
132   Shyam     Chandigarh   Economics
133   Mohan     Delhi        Computers
150   Saurabh   \N           Literature