CeSeekDatabase (CEDB) (Windows CE 5.0)
This function seeks the specified record in an open database. This function is obsolete. Applications should call CeSeekDatabaseEx (CEDB) instead.
This function does not work with EDB databases. For more information on EDB, see EDB Functions.
A RAPI version of this function exists called CeSeekDatabase (RAPI).
CEOIDCeSeekDatabase(HANDLEhDatabase, DWORDdwSeekType, DWORDdwValue, LPDWORDlpdwIndex);
Parameters
hDatabase
[in] Handle to the open database in which to seek the record.dwSeekType
[in] Type of seek operation to perform. The following table shows possible values for dwSeekType.Value Description CEDB_SEEK_CEOID Seeks until finding an object that has the specified object identifier. The dwValue parameter specifies the object identifier. This type of seek operation is very efficient. CEDB_SEEK_VALUESMALLER Starting from the current seek position, seeks backward toward the start of the sort. Always seeks backward, regardless of sort order. In ascending order, this finds the largest value smaller than or equal to the specified value; in descending order, this finds the smallest value larger than or equal to the specified value. If none of the previous records has a value that meets the search criteria, the seek pointer is left at the end of the database and the function returns zero. The dwValue parameter is a pointer to a CEPROPVAL structure.
CEDB_SEEK_VALUEFIRSTEQUAL Begins at the start of the sort and seeks forward until finding the first value that is equal to the specified value. Always seeks forward, regardless of sort order. If the seek operation fails, the seek pointer is left at the end of the database and the function returns zero. The dwValue parameter is a pointer to a CEPROPVAL structure. CEDB_SEEK_VALUENEXTEQUAL Starting from the current seek position, seeks exactly one position forward in the sorted order and checks if the next record is equal in value to the specified value. If so, returns the object identifier of this next record; otherwise, returns zero and leaves the seek pointer at the end of the database. You can use this operation in conjunction with the CEDB_SEEK_VALUEFIRSTEQUAL operation to enumerate all records with an equal value. The dwValue parameter is a pointer to a CEPROPVAL structure. CEDB_SEEK_VALUEGREATER Starting from the current seek position, seeks forward toward the end of the sort. Always seeks forward, regardless of sort order. In ascending order, this finds the smallest value greater than or equal to the specified value; in descending order, this finds the largest value smaller than or equal to the specified value. If none of the following records has a value that meets the search criteria, the seek pointer is left at the end of the database and the function returns zero. The dwValue parameter is a pointer to a CEPROPVAL structure.
CEDB_SEEK_BEGINNING Seeks until finding the record at the specified position from the beginning of the database. The dwValue parameter specifies the number of records to seek from the beginning. CEDB_SEEK_CURRENT Seeks backward or forward from the current position of the seek pointer for the specified number of records. The dwValue parameter specifies the number of records to seek from the current position. The function seeks forward if dwValue is a positive value or backward if it is negative. CEDB_SEEK_END Seeks backward for the specified number of records from the end of the database. The dwValue parameter specifies the number of records to seek from the end. dwValue
[in] Value to use for the seek operation. The meaning of this parameter depends on the value of dwSeekType. It may be a CEOID, a DWORD counter, or a pointer to a CEPROPVAL structure.lpdwIndex
[out] Pointer to a variable that receives the index from the start of the database to the beginning of the record that was found. This parameter can be NULL.Passing a non-NULL value for lpdwIndex will cause the call to be slower and should be avoided whenever possible.
Return Values
The object identifier of the record on which the seek ends indicates success. Zero indicates failure. To get extended error information, call GetLastError. GetLastError may return ERROR_INVALID_PARAMETER if a parameter is invalid.
Remarks
The CeSeekDatabase function always uses the current sort order as specified in the call to the CeOpenDatabaseEx (CEDB) function. If the CEDB_AUTOINCREMENT flag was specified, an automatic seek of one from the current position is done with each read operation that occurs on the database. If a seeks fails, the record pointer points to the same record as before the seek operation.
Note that a seek can only be performed on a sorted property value. After creating a database (using CeCreateDatabaseEx (CEDB)) and opening the database (using CeOpenDatabaseEx), subsequent calls to CeSeekDatabase assume the sort order that was specified in the propid parameter of the call to CeOpenDatabaseEx.
To enter negative values for the CEDB_SEEK_CURRENT case, cast a signed long. This changes the effective range on the record indexes to 31 bits from 32 bits.
When a CEPROPVAL structure is required to seek operation, the propid parameter must be set to the PROPID of the sort order specified in the CeOpenDatabaseEx call.
Using CeWriteRecordProps in conjunction with CeSeekDatabase may result in unexpected seek behavior. See description of CeWriteRecordProps (CEDB) for more details.
Requirements
OS Versions: Windows CE 1.01 and later.
Header: Windbase.h.
Link Library: Coredll.lib.
See Also
CeCreateDatabaseEx (CEDB) | CeOpenDatabaseEx (CEDB) | CEPROPVAL | CeSeekDatabaseEx (CEDB) | CeWriteRecordProps (CEDB)
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