How does kettle handle text data transfer as' 'instead of null

kettle Sometimes, field data is empty during transmission , yes null, However, the target field of transmission should be non empty

such as kettle Three fields were transferred ,id,name,age, Text character this field is empty , What's coming in is null, Field limit error will be reported

This time we can in ${KETTLE_HOME}/.kettle/kettle.properties Add a sentence to the document

# Auto fill blank is ''
KETTLE_EMPTY_STRING_DIFFERS_FROM_NULL=Y

Then for the empty characters in the file , Will automatically switch to ''

tips: This field is only applicable to STRING Type validation , Because the interface tables are all STRING The type field , In this case, time , Numeric fields are also passed in '', An error will be reported when the interface table is imported into the main table ：'' Can not act as DATE or NUMBER

resolvent ：1. When text data is transferred into the interface table , Even if the field type of the interface table is character , Still select its main table field type , Instead of blindly setting STRING

2. Set all to STRING, When the interface table is converted to the main table, the non character fields are case when col1 = '' then null else col1 end col1 transformation