#include <d32dbms.h>
| class TDbQuery |
| Public Member Functions | |
|---|---|
| TDbQuery(const TDesC &, TDbTextComparison) | |
| TDbTextComparison | Comparison() |
| const TDesC & | Query() |
A wrapper for an SQL string combined with a text comparison mode.
An instance of the class is used as a parameter to RDbView::Prepare(), RDbRowSet::FindL() and RDbRowConstraint::Open().
The evaluation of SQL queries or constraints depends on how Text columns are compared so every SQL string is accompanied by a member of the TDbTextComparison enumeration to indicate how comparison is done.
If the SQL string contains a LIKE clause with * (asterisks) wildcard then the characters between them must be no longer than length 255. If only one * exists then the length is taken from the start and to the end of the clause. However, if the clause contains a ? (question mark) wildcard within it then the characters between must be no longer than length 253.
See also: TDbTextComparison RDbView::Prepare() RDbRowSet::FindL() RDbRowConstraint::Open()
| TDbQuery | ( | const TDesC & | aQuery, |
| TDbTextComparison | aComparison = EDbCompareNormal | ||
| ) | [inline] | ||
Constructs a query object from an SQL string and a text comparison mode.
Note that no copy is made of the descriptor passed; it is stored by reference in the query object.
| Parameter | Description |
|---|---|
| aQuery | The SQL string as a descriptor. |
| aComparison | The type of text comparison to use in evaluation of the SQL. If not supplied, normal comparison is used. |
| TDbTextComparison | Comparison | ( | ) | const [inline] |
Returns the text comparison mode for the query object.
Returns: The text comparison mode.
| const TDesC & | Query | ( | ) | const [inline] |
Returns the SQL string in the query object.
Returns: A descriptor containing the SQL string.