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- Records read
- Looping through a data file
- Memos
- Locks
- Miscellaneous
<Source>.Read (Función)
 No disponible con este tipo de conexión
Reads a record in a data file according to a given record number. This read mode is called "Direct access". The record read is loaded in memory. <Source>.State is used to find out the record status (active, crossed or deleted). In most cases, <Source>.Read is used to position in the data file in order to perform a read loop by specifying the record number. Several cases may occur after the call to <Source>.Read: - the specified record number does not exist (greater than the total number of records or negative): no reading is performed and function <Source>.Out returns True.
- the specified record number no longer exists (record scratched, deleted, etc.): no playback is performed and function <Source>.Out returns False.
Use <Source>.State to find out the record status. - the data file is empty: function <Source>.Out returns True.
- the function attempts to block a record already blocked in play mode: function HErrorLock returns True and function <Source>.Out returns True.
 JDBC access: lock management is not supported for databases that are accessed through JDBC.
This function can be used with the data files (indexed or not) and with the HFSQL views. // Sequential iteration to display the name of all customers
i is int
FOR i = 1 _TO_ Customer.NbRec(hStateAll)
Customer.Read(i)
IF Customer.State() = hStateActive THEN
Info("Customer name: " + Customer.Name)
END
END
Sintaxis
<Result> = <Source>.Read([<Record number> [, <Options>]])
<Result>: Booleano - True if the record was read,
- False in the event of an error (block, end of data file, etc.): the record is not read. HError is used to identify the error.
<Source>: Tipo de fuente especificada Name of the HFSQL data file, view or query used. <Record number>: Entero opcional Number of the record to read.If this parameter is not specified (or is equal to 0 or to the hCurrentRecNum constant), <Source>.Read will read the current record.
<Options>: Constante opcional Configures the lock set on the record read by <Source>.Read: | | | hLockNo | No blocking: the Record can be played back or modified by another application during playback. | | hLockReadWrite | Read/write lock: the record being read cannot be read or modified by another application. | | hLockWrite | Write lock: the record currently read can be read by another application but it cannot be modified by another application. |
Observaciones Looping through a data file Memos The memos associated with the record can be automatically read (or not) when reading the record. <Source>.SetMemo is used to customize this automatic read operation. If the memos are supported, the associated text memos are read when the record is read. The binary memos are read only when they are explicitly used ( <Source>.ExtractMemo).
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