应用程序调用 SQLGetTypeInfo 来确定数据源支持哪些数据类型以及这些数据类型的特征。 下表显示了 SQLGetTypeInfo 为支持SQL_CHAR、SQL_LONGVARCHAR、SQL_DECIMAL、SQL_REAL、SQL_DATETIME、SQL_INTERVAL_YEAR和SQL_INTERVAL_DAY_TO_SECOND的数据源返回的示例结果集。
| TYPE_NAME | DATA_TYPE | COLUMN_SIZE | LITERAL_PREFIX | LITERAL_SUFFIX | CREATE_PARAMS | NULLABLE |
|---|---|---|---|---|---|---|
| “char” | SQL_CHAR | 255 | "'" | "'" | “length” | SQL_TRUE |
| "text" | SQL_LONGVARCHAR | 2147483647 | "'" | "'" | <Null> | SQL_TRUE |
| “decimal” | SQL_DECIMAL | 28 | <Null> | <Null> | “precision， scale” |
SQL_TRUE |
| “real” | SQL_REAL | 7 | <Null> | <Null> | <Null> | SQL_TRUE |
| “datetime” | SQL_TYPE_TIMESTAMP | 23 | "'" | "'" | <Null> | SQL_TRUE |
| “INTERVAL YEAR () TO YEAR” | SQL_INTERVAL_YEAR | 9 | "'" | "'" | “precision” | SQL_TRUE |
| “INTERVAL DAY () TO FRACTION (5) ” | SQL_INTERVAL_DAY_TO_SECOND | 24 | "'" | "'" | “precision” | SQL_TRUE |
| DATA_TYPE | CASE_SENSITIVE | SEARCHABLE | UNSIGNED_ATTRIBUTE | FIXED_PREC_SCALE | AUTO_UNIQUE_VALUE | LOCAL_TYPE_NAME |
|---|---|---|---|---|---|---|
| SQL_CHAR | SQL_FALSE | SQL_SEARCHABLE | <Null> | SQL_FALSE | <Null> | “char” |
| SQL_LONGVARCHAR | SQL_FALSE | SQL_PRED_CHAR | <Null> | SQL_FALSE | <Null> | "text" |
| SQL_DECIMAL | SQL_FALSE | SQL_PRED_BASIC | SQL_FALSE | SQL_FALSE | SQL_FALSE | “decimal” |
| SQL_REAL | SQL_FALSE | SQL_PRED_BASIC | SQL_FALSE | SQL_FALSE | SQL_FALSE | “real” |
| SQL_TYPE_TIMESTAMP | SQL_FALSE | SQL_SEARCHABLE | <Null> | SQL_FALSE | <Null> | “datetime” |
| SQL_INTERVAL_YEAR | SQL_FALSE | SQL_SEARCHABLE | <Null> | SQL_FALSE | <Null> | “INTERVAL YEAR () TO YEAR” |
| SQL_INTERVAL_DAY_TO_SECOND | SQL_FALSE | SQL_PRED_BASIC | <Null> | SQL_FALSE | <Null> | “INTERVAL DAY () TO FRACTION (5) ” |
| DATA_TYPE | MINIMUM_SCALE | MAXIMUM_SCALE | SQL_DATA_TYPE | SQL_DATETIME_SUB | NUM_PREC_RADIX | INTERVAL_PRECISION |
|---|---|---|---|---|---|---|
| SQL_CHAR | <Null> | <Null> | SQL_CHAR | <Null> | <Null> | <Null> |
| SQL_LONGVARCHAR | <Null> | <Null> | SQL_LONGVARCHAR | <Null> | <Null> | <Null> |
| SQL_DECIMAL | 0 | 28 | SQL_DECIMAL | <Null> | 10 | <Null> |
| SQL_REAL | <Null> | <Null> | SQL_REAL | <Null> | 10 | <Null> |
| SQL_TYPE_TIMESTAMP | 3 | 3 | SQL_DATETIME | SQL_CODE_TIMESTAMP | <Null> | 12 |
| SQL_INTERVAL_YEAR | 0 | 0 | SQL_INTERVAL | SQL_CODE_INTERVALYEAR | <Null> | 9 |
| SQL_INTERVAL_DAY_TO_SECOND | 5 | 5 | SQL_INTERVAL | SQL_CODE_INTERVALDAY_TO_SECOND | <Null> | 9 |