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- Read operation based on a key
- Comparison between <Source>.Next and .ReadNext
- Miscellaneous
- Locks
<Source>.Next (Function) In french: <Source>.Suivant
Not available with this kind of connection
Sets the position on the next data file record according to a browse item. The record is not read.The number of the current record is modified only when it is returned by <Source>.RecNum. For the functions that handle the current record number ( <Source>.Delete, <Source>.Read, <Source>.Modify, etc.), the value of this number is not updated: you must use <Source>.RecNum(). For example: not to do:
but
Customer.Delete(Customer.RecNum())
Values in the browse item are read in ascending order (see Remarks for more details). Caution: The record loaded in memory is not modified. The HFSQL variables (Customer.Name for example, which means the Name item of Customer file) are not updated. In most cases, <Source>.Next sets the position in the data file to loop through the records that match a condition. <Source>.Next is used to position on the next record corresponding to the condition. Several cases may occur after the call to <Source>.Next: - a record corresponding to the condition was found: <Source>.Found returns True
- the data file is empty or there is no record corresponding to the condition: <Source>.Out returns True
Remarks: Values in the browse item are read in ascending order (for more details, see the remarks). Caution: The record loaded in memory is not modified. The HFSQL variables (for example Customer.Name, i.e. the Name item of the Customer file) are not updated. Generally, <Source>.Next sets the position in the data file during a loop operation. Several cases may occur after the call to <Source>.Next: Customer.First(Name) WHILE Customer.Out() = False // Process the record Customer.Next(Name) END Syntax
<Result> = <Source>.Hnext([<Search key item> [, <Options>]])
<Result>: Boolean - True if the position was set,
- False if an error occurred. This problem can be caused by:
<Source>: Type corresponding to the specified source Name of the HFSQL data file. <Search key item>: Optional character string Name of the key item used to loop through the data file. If this name is not specified, <Source>.Next will use the last browse item used on this data file by the last HFSQL management function (function starting with "H"). If this item does not exist, the best browse item is automatically used. <Options>: Optional constant Configures the lock and the management of duplicates performed on the record selected by <Source>.Next: | | hDistinct | If there are any duplicates, sets the position on a single record of the duplicates. This parameter is taken into account only if the iteration is performed on a key item. By default, all duplicates are iterated over.
| hLockNo | No lock: the record can be read or modified by another application. | hLockReadWrite | Lock in read/write mode: the selected record cannot be read or modified by another application. | hLockWrite | Lock in write mode: the selected record can be read by another application but it cannot be modified. |
To change the lock mode, use: Remarks Read operation based on a key <Source>.Next positions on the next record with the greatest key value. The sort order taken into account is the one specified in the analysis for this key.
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