The following table shows the corresponding empty value for each data type and DBMS.
DBMS |
Numeric |
Date |
Datetime (**) |
Character (n) |
Varchar |
Long Varchar |
Blob |
SQL Server |
0 |
1753-01-01 00:00:00.000 |
1753-01-01 00:00:00.000 |
n blanks |
<empty string> |
<empty string> |
<empty file> |
Oracle |
0 |
0001-01-01 00:00:00 |
0001-01-01 00:00:00 |
n blanks |
1 blank |
1 blank |
<empty file> |
DB2 UDB |
0 |
0001-01-01 |
0001-01-01 00:00:00.000 |
n blanks |
<empty string> |
<empty string> |
<empty file> |
DB2 iSeries |
0 |
"00000000"
or 0001-01-01 (*) |
0001-01-01-00.00.00 |
n blanks |
<empty string> |
<empty string> |
<empty file> |
MySQL |
0 |
1000-01-01 |
1000-01-01 00:00:00 |
<empty string> |
<empty string> |
<empty string> |
<empty file> |
PostgreSQL |
0 |
0001-01-01 |
0001-01-01 00:00:00 |
n blanks |
<empty string> |
<empty string> |
<empty file> |
Informix |
0 |
0001-01-01 |
0001-01-01 00:00:00 |
n blanks |
<empty string> |
<empty string> |
<empty file> |
(*) For DB2 iSeries, the empty value depends on the Date Data Type Definition model property value.
(**) Empty values are invariable with respect to the Precision. More information at DateTime data type