This table shows the recommended data types for extracting data from the databases supported in Qt. Note that types used in Qt are not necessarily valid as input types to a specific database system. e.g., A double might work perfectly as input for floating point records in a particular database, but not necessarily as a storage format for output from that database, because it would be stored with 64-bit precision in C++.
| IBM DB2 data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| SMALLINT | 16-bit signed integer | typedef qint16 |
| INTEGER | 32-bit signed integer | typedef qint32 |
| BIGINT | 64-bit signed integer | typedef qint64 |
| REAL | 32-bit Single-precision floating point | typedef qreal |
| DOUBLE PRECISION | 64-bit Double-precision floating point | Mapped to QString for high precision doubles, otherwise qreal |
| FLOAT | 64-bit Double-precision floating point | typedef qreal |
| CHAR | Fixed-length, null-terminated character string | Mapped to QString |
| VARCHAR | Null-terminated varying length string | Mapped to QString |
| LONG VARCHAR | Not null-terminated varying length character string | Mapped to QString |
| BLOB | Not null-terminated varying binary string with 4-byte string length indicator | Mapped to QByteArray |
| CLOB | Character large string object | Mapped to QString |
| DATE | Null-terminated character string of the following format: yyyy-mm-dd | Mapped to QDate |
| TIME | Null-terminated character string of the following format: hh.mm.ss | Mapped to QTime |
| TIMESTAMP | Null-terminated character string of the following format: yyyy-mm-dd-hh.mm.ss.nnnnnn | Mapped to QDateTime |
| Borland InterBase data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| BOOLEAN | Boolean | bool |
| TINYINT | 8 bit signed integer | typedef qint8 |
| SMALLINT | 16-bit signed integer | typedef qint16 |
| INTEGER | 32-bit signed integer | typedef qint32 |
| BIGINT LONG | 64-bit signed integer | typedef qint64 |
| REAL FLOAT | 32-bit floating point | typedef qreal |
| FLOAT | 64-bit floating point | typedef qreal |
| DOUBLE | 64-bit floating point | typedef qreal |
| DOUBLE PRECISION | 64-bit Double-precision floating point | Mapped to QString for high precision doubles, otherwise qreal |
| VARCHAR STRING | Character string, Unicode | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| DATE | Displays date. Format: 'yyyy-mm-dd' | Mapped to QDate |
| TIME | Displays time. Format is 'hh:mm:ss' in 24-hour format | Mapped to QTime |
| TIMESTAMP | Displays a timestamp. Format is 'yyyy-mm-dd hh:mm:ss' | Mapped to QDateTime |
| MySQL data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| TINYINT | 8 bit signed integer | typedef qint8 |
| TINYINT UNSIGNED | 8 bit unsigned integer | typedef quint8 |
| SMALLINT | 16-bit signed integer | typedef qint16 |
| SMALLINT UNSIGNED | 16-bit unsigned integer | typedef quint16 |
| INT | 32-bit signed integer | typedef qint32 |
| INT UNSIGNED | 32-bit unsigned integer | typedef quint32 |
| BIGINT | 64-bit signed integer | typedef qint64 |
| FLOAT | 32-bit Floating Point | typedef qreal |
| DOUBLE | 64-bit Floating Point | Mapped to QString for high precision doubles, otherwise qreal |
| CHAR | Character string | Mapped to QString |
| VARCHAR | Character string | Mapped to QString |
| TINYTEXT | Character string | Mapped to QString |
| TEXT | Character string | Mapped to QString |
| MEDIUMTEXT | Character string | Mapped to QString |
| LONGTEXT | Character string | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| all BLOB types | BLOB | Mapped to QByteArray |
| DATE | Date without Time | Mapped to QDate |
| DATETIME | Date and Time | Mapped to QDateTime |
| TIMESTAMP | Date and Time | Mapped to QDateTime |
| TIME | Time | Mapped to QTime |
| YEAR | Year (int) | Mapped to QDateTime |
| ENUM | Enumeration of Value Set | Mapped to QString |
| Oracle Call Interface data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| NUMBER | FLOAT, DOUBLE, PRECISIONc REAL | Mapped to QString for high precision doubles, otherwise qreal |
| NUMBER(38) | INTEGER INT SMALLINT | typedef qint8/16/32/64 |
| NUMBER(p,s) | NUMERIC(p,s) DECIMAL(p,s)a | Mapped to QString |
| NVARCHAR2(n) | Character string (NATIONAL CHARACTER VARYING(n) NATIONAL CHAR VARYING(n) NCHAR VARYING(n)) | Mapped to QString |
| NCHAR(n) | Character string (NATIONAL CHARACTER(n) NATIONAL CHAR(n) NCHAR(n)) | Mapped to QString |
| CHAR(n) | Character string (CHARACTER(n) CHAR(n)) | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| BLOB | A binary large object | Mapped to QByteArray |
| TIMESTAMP | Year, month, and day values of date, as well as hour, minute, and second values of time | Mapped to QDateTime |
| ODBC data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| BIT | Boolean | BOOL |
| TINYINT | 8 bit integer | typedef qint8 |
| SMALLINT | 16-bit signed integer | typedef qint16 |
| INTEGER | 32-bit signed integer | typedef qint32 |
| BIGINT | 64-bit signed integer | typedef qint64 |
| REAL | 32-bit Single-precision floating point | typedef qreal |
| FLOAT | 64-bit Double floating point | typedef qreal |
| DOUBLE | 64-bit Double floating point | Mapped to QString for high precision doubles, otherwise qreal |
| CHAR | Character string | Mapped to QString |
| VARCHAR | Character string | Mapped to QString |
| LONGVARCHAR | Character string | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| DATE | Character string | Mapped to QDate |
| TIME | Character Time, Character string | Mapped to QTime |
| TIMESTAMP | Character Time, Character string | Mapped to QDateTime |
| PostgreSQL data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| BOOLEAN | Boolean | bool |
| SMALLINT | 16-bit signed integer | typedef qint16 |
| INTEGER | 32-bit signed integer | typedef qint32 |
| BIGINT | 64-bit signed integer | typedef qint64 |
| REAL | 32-bit variable-precision floating point | typedef qreal |
| DOUBLE PRECISION | 64-bit variable-precision floating point | Mapped to QString for high precision doubles, otherwise qreal |
| DECIMAL VARIABLE | user-specified precision, exact | typedef qreal |
| NUMERIC VARIABLE | user-specified precision, exact | typedef qreal |
| VARCHAR | variable-length character string | Mapped to QString |
| CHARACTER | Character string of fixed-length | Mapped to QString |
| TEXT | Character string of variable-length | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| TIMESTAMP | 8 bytes, both date and time | Mapped to QDateTime |
| TIMESTAMP | 8 bytes, both date and time, with time zone | Mapped to QDateTime |
| DATE | 4 bytes, dates only | Mapped to QDate |
| TIME | 8 bytes, times of day only 00:00:00.00 - 23:59:59.99 | Mapped to QTime |
| TIME | 12 bytes times of day only, with time zone 00:00:00.00+12 | Mapped to QDateTime |
| QSQLITE SQLite version 3 data type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| NULL | NULL value. | NULL |
| INTEGER | Signed integer, stored in 8, 16, 24, 32, 48, or 64-bits depending on the magnitude of the value. | typedef qint8/16/32/64 |
| REAL | 64-bit floating point value. | typedef qreal |
| TEXT | Character string (UTF-8, UTF-16BE or UTF-16-LE). | Mapped to QString |
| CLOB | Character large string object | Mapped to QString |
| BLOB | The value is a BLOB of data, stored exactly as it was input. | Mapped to QByteArray |
| Mimer SQL type | SQL type description | Recommended input (C++ or Qt data type) |
|---|---|---|
| SMALLINT | 16-bit signed integer | typedef qint16 |
| INTEGER | 32-bit signed integer | typedef qint32 |
| INTEGER(n) | Integer with up to 45 digits precision | Mapped to QString |
| BIGINT | 64-bit signed integer | typedef qint64 |
| REAL | 32-bit Single-precision IEEE floating point | typedef float |
| DOUBLE PRECISION | 64-bit Double-precision IEEE floating point | Mapped to QString for high precision doubles, otherwise qreal |
| FLOAT | 64-bit Double-precision IEEE floating point | Mapped to QString for high precision doubles, otherwise qreal |
| FLOAT(n) | Floating point with up to 45 digits precision | Mapped to QString |
| DECIMAL(p,s) | Decimal with up to 45 digits precision and scale | Mapped to QString |
| CHAR | Fixed-length character Latin-1 string (CHAR or character) | Mapped to QString |
| VARCHAR | Variable length Latin-1 string (VARCHAR or CHARACTER VARYING) | Mapped to QString |
| NCHAR | Fixed-length Unicode string (NCHAR or NATIONAL CHARACTER) | Mapped to QString |
| NVARCHAR | Variable length Unicode string (NVARCHAR or NATIONAL CHARACTER VARYING) | Mapped to QString |
| BINARY | Fixed length binary data | Mapped to QByteArray |
| VARBINARY | Variable length binary data (VARBINARY or BINARY VARYING) | Mapped to QByteArray |
| BLOB | Binary large object (BLOB or BINARY LARGE OBJECT) | Mapped to QByteArray |
| CLOB | Latin-1 character large object (CLOB or CHARACTER LARGE OBJECT) | Mapped to QString |
| NCLOB | Unicode character large object (NCLOB or NATIONAL CHARACTER LARGE OBJECT) | Mapped to QString |
| DATE | Date consisting of year, month, and day | Mapped to QDate |
| TIME | Time consisting of hours, minute, seconds with optional fractional seconds | Mapped to QTime |
| TIMESTAMP | Date and time with optional fractional seconds | Mapped to QDateTime |
| BUILTIN.UUID | Universally unique identifier | Mapped to QUuid |
| BOOLEAN | Boolean | bool |
| INTERVAL YEAR(7) | Year, format '±yyyyyyy' (max precision) | Mapped to QString |
| INTERVAL YEAR(7) TO MONTH | Year to month, format '±yyyyyyy-mm' (max precision) | Mapped to QString |
| INTERVAL MONTH(7) | Month, format '±mmmmmmm' (max precision) | Mapped to QString |
| INTERVAL DAY(7) | Day, format '±ddddddd' (max precision) | Mapped to QString |
| INTERVAL DAY(7) TO HOUR | Day to hour, format '±ddddddd hh' (max precision) | Mapped to QString |
| INTERVAL DAY(7) TO MINUTE | Day to minute, format '±ddddddd hh:mm' (max precision) | Mapped to QString |
| INTERVAL DAY(7) TO SECOND(9) | Day to second, format '±ddddddd hh:mm:ss[.fffffffff]' (max precision) | Mapped to QString |
| INTERVAL HOUR(8) | Hour, format '±hhhhhhhh' (max precision) | Mapped to QString |
| INTERVAL HOUR(8) TO MINUTE | Hour to minute, format '±hhhhhhhh:mm' (max precision) | Mapped to QString |
| INTERVAL HOUR(8) TO SECOND(9) | Hour to second, format '±hhhhhhhh:mm:ss[.fffffffff]' (max precision) | Mapped to QString |
| INTERVAL MINUTE(10) | Minute, format '±mmmmmmmmmm' (max precision) | Mapped to QString |
| INTERVAL MINUTE(10) TO SECOND(9) | Minute to second, format '±mmmmmmmmmm:ss[.fffffffff]' (max precision) | Mapped to QString |
| INTERVAL SECOND(12,9) | Second, format '±ssssssssssss[.fffffffff]' (max precision) | Mapped to QString |
