SQL0407N Assignment of a NULL value to a NOT NULL column "TBSPACEID=2, TABLEID=50, COLNO=8" is not allowed. SQLSTATE=23502
上面的错误信息没有直接给出table名，可以通过下面的语句得到table和column
SELECT * FROM SYSCAT.TABLES WHERE TBSPACEID = 2 AND TABLEID = 50
SELECT * FROM SYSCAT.COLUMNS WHERE TABNAME= '*******' AND COLNO = 8