CSV File `sample.csv'

"Test"
"100.22"
""

Import via CsvRead

CREATE TABLE TEST(TEST DECIMAL(12,2) NULL);
INSERT INTO TEST SELECT * FROM CsvRead('sample.csv');

Will fail at row 2 with

org.h2.jdbc.JdbcSQLDataException: Data conversion error converting "'' (TEST: ""TEST"" DECIMAL(12, 2))";

Reason: the empty String '' is not interpreted as NULL, but instead forwarded to a call of new BigDecimal('') which will fail.