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- Handling a deleted record
- Number of deleted records
- Deleting a record from a query
- Version of data file
- Size of the data file
- Deletion and lock
- xBase/FoxFro
HDelete (Function)
 No disponible con este tipo de conexión
Deletes a record from a data file (query or view). The record is deleted logically and physically. It cannot be restored (unlike the records crossed by HCross). The following operations are performed: - the record is deleted: the record is rendered inactive and is no longer referenced in the index. The data is not kept.
- the indexes (corresponding to the record keys) are deleted from the index file.
- the memos associated with the record are deleted from the memo file.
After running HDelete, the record is inserted in the list of deleted records and will be reused by HAdd. WINDEV, WINDEV Mobile and WEBDEV offer automatic error handling for the following 5 types of error: Duplicate error, Integrity error, Password error, Modification conflict and status error during modification conflict, Blocking error. For more details, see HFSQL error handling help. Note To delete all records in a data file, use HDeleteAll.
HReadSeekFirst(Orders, CustNum, ValCustNum)
WHILE HFound() = True
HDelete()
HReadNext()
END
FOR EACH Order where CustNum = CustNumVal
HDelete()
END
Sintaxis
<Result> = HDelete([<Data file> [, <Record number> [, <Options>]]])
<Result>: Boolean - True if the record was deleted,
- False if a problem occurred (locked record, etc. (see the special cases)). HErrorInfo is used to identify the error.
If the record to delete is already deleted, HDelete returns True.
<Data file>: Optional character string Name of HFSQL data file or view used. If this parameter is an empty string (""), HDelete manipulates the last data file used by the last HFSQL function (function starting with "H"). <Record number>: Optional integer Number of the record to delete. If this parameter is not specified (if it is equal to 0 or to the hCurrentRecNum constant), the current record will be deleted. However, the current record will remain the deleted record.
CAUTION: Do not confuse the Record number with the automation identifier associated with the Record.
In most cases, these two numbers are not identical. The record number is returned by HRecNum.
<Options>: Optional constant Configures the integrity management performed on the deleted record. | | | hIgnoreIntegrity | Ignores the integrity check for this operation, even if the automatic integrity check is enabled (HSetIntegrity) |
Observaciones Deleting a record from a query Deleting a record from a query can be performed: - in the query result
- in the data files handled by the query (hModifyFile constant used in HExecuteQuery or HExecuteSQLQuery). In this case, the hWithFilter constant is automatically selected.
Regardless of how the query is executed (with or without the constant hWithFilterconstant), the HDelete function can only be used on single-file requests. Caution: - On non-HFSQL data files, there is no need to specify the constant hModifiesFile in functions HExecuteQuery or HExecuteSQLQuery: data files contributing to the query are automatically modified when the query result is modified.
- Records cannot be deleted from a query that uses groups or aggregates.
- Integrity and duplicates are not managed by operations on multi-file queries: it is advisable to use transactions to avoid any problems.
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