转载自：http://blog.csdn.net/kevin601195993/article/details/7655903
| Standard datatype | DBMS-specific physical data type | Content | Length |
|---|---|---|---|
| Integer | int / INTEGER | 32-bit integer | — |
| Short Integer | smallint / SMALLINT | 16-bit integer | — |
| Long Integer | int / INTEGER | 32-bit integer | — |
| Byte | tinyint / SMALLINT | 256 values | — |
| Number | numeric / NUMBER | Numbers with a fixed decimal point | Fixed |
| Decimal | decimal / NUMBER | Numbers with a fixed decimal point | Fixed |
| Float | float / FLOAT | 32-bit floating point numbers | Fixed |
| Short Float | real / FLOAT | Less than 32-bit point decimal number | — |
| Long Float | double precision / BINARY DOUBLE | 64-bit floating point numbers | — |
| Money | money / NUMBER | Numbers with a fixed decimal point | Fixed |
| Serial | numeric / NUMBER | Automatically incremented numbers | Fixed |
| Boolean | bit / SMALLINT | Two opposing values (true/false; yes/no; 1/0) | — |
Character data types
The following character data types are available:
| Standard data type | DBMS-specific physical data type | Content | Length |
|---|---|---|---|
| Characters | char / CHAR | Character strings | Fixed |
| Variable Characters | varchar / VARCHAR2 | Character strings | Maximum |
| Long Characters | varchar / CLOB | Character strings | Maximum |
| Long Var Characters | text / CLOB | Character strings | Maximum |
| Text | text / CLOB | Character strings | Maximum |
| Multibyte | nchar / NCHAR | Multibyte character strings | Fixed |
| Variable Multibyte | nvarchar / NVARCHAR2 | Multibyte character strings | Maximum |
Time data types
| Standard data type | DBMS-specific physical data type | Content | Length |
|---|---|---|---|
| Date | date / DATE | Day, month, year | — |
| Time | time / DATE | Hour, minute, and second | — |
| Date & Time | datetime / DATE | Date and time | — |
| Timestamp | timestamp / TIMESTAMP | System date and time | — |
Other data types
The following other data types are available:
| Standard data type | DBMS-specific physical data type | Content | Length |
|---|---|---|---|
| Binary | binary / RAW | Binary strings | Maximum |
| Long Binary | image / BLOB | Binary strings | Maximum |
| Bitmap | image / BLOB | Images in bitmap format (BMP) | Maximum |
| Image | image / BLOB | Images | Maximum |
| OLE | image / BLOB | OLE links | Maximum |
| Other | — | User-defined data type | — |
| Undefined | undefined | Undefined. Replaced by the default data type at generation. | — |