LOAD_FILE()

Function description

The LOAD_FILE() function is used to read the contents of the file pointed to by the datalink type.

Note

When using load_file() to load a large file, if the file data volume is too large, the system memory limit may be exceeded, causing memory overflow. It is recommended to use it in combination with offset and size of DATALINK.

Function syntax

>LOAD_FILE(datalink_type_data);

Parameter explanation

Parameters	Description
datalink_type_data	datalink type data can be converted using the cast() function

Example

There is a file t1.csv under /Users/admin/case

(base) admin@192 case % cat t1.csv 
this is a test message

create table t1 (col1 int, col2 datalink);
create stage stage1 url='file:///Users/admin/case/';
insert into t1 values (1, 'file:///Users/admin/case/t1.csv');
insert into t1 values (2, 'stage://stage1//t1.csv');

mysql> select * from t1;
+------+---------------------------------+
| col1 | col2                            |
+------+---------------------------------+
|    1 | file:///Users/admin/case/t1.csv |
|    2 | stage://stage1//t1.csv          |
+------+---------------------------------+
2 rows in set (0.00 sec)

mysql> select col1, load_file(col2) from t1;
+------+-------------------------+
| col1 | load_file(col2)         |
+------+-------------------------+
|    1 | this is a test message
 |
|    2 | this is a test message
 |
+------+-------------------------+
2 rows in set (0.01 sec)


mysql> select load_file(cast('file:///Users/admin/case/t1.csv' as datalink));
+--------------------------------------------------------------+
| load_file(cast(file:///Users/admin/case/t1.csv as datalink)) |
+--------------------------------------------------------------+
| this is a test message
                                      |
+--------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select load_file(cast('stage://stage1//t1.csv' as datalink));
+-----------------------------------------------------+
| load_file(cast(stage://stage1//t1.csv as datalink)) |
+-----------------------------------------------------+
| this is a test message
                             |
+-----------------------------------------------------+
1 row in set (0.00 sec)