The issue here is due to the system trying to insert a NULL value into a field WITHOUT specifying the JDBC type. While most of databases deal with it internally, some *cough* professional databases like SQL Server and Oracle leave this to the user. This specific issue is manifested when trying to insert a NULL in a field declared of type FLOAT.
When node properties are saved in the “normal” tables, their metadata are collected. The item of interest here is the JDBC TYPE of such property, which is later used during the SQL operation.
The type is then used when the data is inserted using the NodePropertyValue class.
Status after testing all database (with an automatic test):
Postgres: all good
SQLServer: cannot insert null in double or float
Oracle: cannot insert any null
MySQL: all good
MariaDB: assuming all good, will see what Travis says :)
So we need to provide a fix for SQLServer and Oracle