Determining equivalent SQL and C or C++ data types
The precompiler determines the base SQLTYPE and SQLLEN of host variables based on the table. If a host variable appears with an indicator variable, the SQLTYPE is the base SQLTYPE plus one.
| C or C++ data type | SQLTYPE of host variable | SQLLEN of host variable | SQL data type |
|---|---|---|---|
| short int | 500 | 2 | SMALLINT |
| long int | 496 | 4 | INTEGER |
| long long int | 492 | 8 | BIGINT |
| decimal(p,s) | 484 | p in byte 1, s in byte 2 | DECIMAL (p,s) |
| _Decimal32 | 996 | 4 | Treated as DECFLOAT(7) although SQL does not directly support this data type. |
| _Decimal64 | 996 | 8 | DECFLOAT(16) |
| _Decimal128 | 996 | 16 | DECFLOAT(34) |
| float | 480 | 4 | FLOAT (single precision) |
| double | 480 | 8 | FLOAT (double precision) |
| single-character form | 452 | 1 | CHAR(1) |
| NUL-terminated character form | 460 | length | VARCHAR (length - 1) |
| VARCHAR structured form | 448 | length | VARCHAR (length) |
| single-graphic form | 468 | 1 | GRAPHIC(1) |
| NUL-terminated single-graphic form | 400 | length | VARGRAPHIC (length - 1) |
| VARGRAPHIC structured form | 464 | length | VARGRAPHIC (length) |
You can use the following table to determine the C or C++ data type that is equivalent to a given SQL data type.
| SQL data type | C or C++ data type | Notes |
|---|---|---|
| SMALLINT | short int | |
| INTEGER | long int | |
| BIGINT | long long int | |
| DECIMAL(p,s) | decimal(p,s) | p is a positive integer from 1 to 63, and s is a positive integer from 0 to 63. |
| NUMERIC(p,s) or nonzero scale binary | No exact equivalent | Use DECIMAL (p,s). |
| DECFLOAT(16) | _Decimal64 | Only supported in C. |
| DECFLOAT(34) | _Decimal128 | Only supported in C. |
| FLOAT (single precision) | float | |
| FLOAT (double precision) | double | |
| CHAR(1) | single-character form | |
| CHAR(n) | No exact equivalent | If n>1, use NUL-terminated character form. |
| VARCHAR(n) | NUL-terminated character form | Allow at least n+1 to accommodate
the NUL-terminator. If data can contain character NULs (/0), use VARCHAR
structured form or SQL VARCHAR. n is a positive integer. The maximum value of n is 32740. |
| VARCHAR structured form | The maximum value of n is 32740. The SQL VARCHAR form may also be used. | |
| CLOB | None | Use SQL TYPE IS to declare a CLOB in C or C++. |
| GRAPHIC (1) | single-graphic form | |
| GRAPHIC (n) | No exact equivalent | |
| VARGRAPHIC(n) | NUL-terminated graphic form | If n > 1, use NUL-terminated graphic form. |
| VARGRAPHIC structured form | If data can contain graphic NUL values (/0/0), use VARGRAPHIC
structured form. Allow at least n + 1 to accommodate the NUL-terminator.
n is a positive integer. The maximum value of n is 16370. |
|
| DBCLOB | None | Use SQL TYPE IS to declare a DBCLOB in C or C++. |
| BINARY | None | Use SQL TYPE IS to declare a BINARY in C or C++. |
| VARBINARY | None | Use SQL TYPE IS to declare a VARBINARY in C or C++. |
| BLOB | None | Use SQL TYPE IS to declare a BLOB in C or C++. |
| DATE | NUL-terminated character form | If the format is *USA, *ISO, *JIS, or *EUR, allow at least 11 characters to accommodate the NUL-terminator. If the format is *MDY, *YMD, or *DMY, allow at least 9 characters to accommodate the NUL-terminator. If the format is *JUL, allow at least 7 characters to accommodate the NUL-terminator. |
| VARCHAR structured form | If the format is *USA, *ISO, *JIS, or *EUR, allow at least 10 characters. If the format is *MDY, *YMD, or *DMY, allow at least 8 characters. If the format is *JUL, allow at least 6 characters. | |
| TIME | NUL-terminated character form | Allow at least 7 characters (9 to include seconds) to accommodate the NUL-terminator. |
| VARCHAR structured form | Allow at least 6 characters; 8 to include seconds. | |
| TIMESTAMP | NUL-terminated character form | Allow at least 20 characters (33 to include all fractional seconds) to accommodate the NUL-terminator. If n is less than 33, truncation occurs on the fractional seconds part. |
| VARCHAR structured form | Allow at least 19 characters. To include all fractional seconds, allow 32 characters. If the number of characters is less than 32, truncation occurs on the fractional seconds part. | |
| XML | None | Use SQL TYPE IS to declare XML in C or C++. |
| DATALINK | Not supported | |
| ROWID | None | Use SQL TYPE IS to declare a ROWID in C or C++. |
| Result set locator | None | Use SQL TYPE IS to declare a result set locator in C or C++. |