今天从ORACLE导出数据文本格式的到MYSQL 5.6 发现
load data infile Incorrect date value ''
这种报错，从5.6开始在严格模式下插入数据如果是数字和日期
mysql> insert into testnull1 values('','test','');
ERROR 1366 (HY000): Incorrect integer value: '' for column 'id' at row 1
mysql> insert into testnull1 values(1,'test','');
ERROR 1292 (22007): Incorrect datetime value: '' for column 'dt' at row 1
会报错，实际上我们希望''为NULL；
5.6如果表结构是如果表是int,varchar,datetime
后如果通过 load data infile 如果记录如下
,test,
同样会把空值转换为''会报如上的错，这个时候就要用\N来代替。
那么如果从ORACLE中导出
select nvl(to_char(id),'\N'),nvl(name,'\N'),to_char(dt,'yyyy-mm-dd hh24:mi:ss') from testnulli;
将NULL值转换为\N如下：
create table testnulli
(id int,name varchar2(20),dt date);
insert into testnulli
values(1,'gaopeng',to_date('2010-10-10 12:02:01','YYYY-MM-DD HH24:MI:SS'));
insert into testnulli
values(null,'gaopeng',null);
DECLARE
row_result varchar2(4000);
selectsql varchar2(4000);
qrycursor SYS_REFCURSOR;
txt_handle UTL_FILE.file_type;
BEGIN
--selectsql := 'select id || '','' || name || '','' || dti from testdump where name = ''gaopeng'' and dti > to_date(''2015-03-17 00:00:00'', ''yyyy-mm-dd hh24:mi:ss'')';
selectsql := 'select nvl(to_char(id),''\N'')||'',''||nvl(name,''\N'')||'',''||nvl(to_char(dt,''yyyy-mm-dd hh24:mi:ss''),''\N'') from testnulli';
txt_handle := UTL_FILE.FOPEN('DATA_PUMP_DIR', 'testnull.txt', 'w', 32767);
open qrycursor for selectsql;
loop
fetch qrycursor
into row_result;
exit when qrycursor%notfound;
UTL_FILE.PUT_LINE(txt_handle, row_result);
end loop;
--关闭游标
close qrycursor;
UTL_FILE.FCLOSE(txt_handle);
end;
导出的文本如下：
1,gaopeng,2010-10-10 12:02:01
\N,gaopeng,\N
然后再次 load data infile 就不会出问题
mysql> load data infile '/tmp/testnull.txt' into table testnull1 fields terminated by ',' ;
Query OK, 2 rows affected (0.01 sec)
Records: 2 Deleted: 0 Skipped: 0 Warnings: 0
mysql> select * from testnull1;
+------+---------+---------------------+
| id | name | dt |
+------+---------+---------------------+
| 1 | gaopeng | 2010-10-10 12:02:01 |
| NULL | gaopeng | NULL |
+------+---------+---------------------+
2 rows in set (0.02 sec)
实际上
mysql> insert into testnull1 values(\N,'test',\N);
Query OK, 1 row affected (0.00 sec)
等价于
mysql> insert into testnull1 values(null,'test',null);
Query OK, 1 row affected (0.01 sec)