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New WINDEV, WEBDEV and WINDEV Mobile 25 feature!
  • Browse item
  • Browsing queries
  • Locks
  • Memos
  • Password
  • Native XML Connector
  • Miscellaneous
WINDEV
WindowsLinuxUniversal Windows 10 AppJavaReports and QueriesUser code (UMC)
WEBDEV
WindowsLinuxPHPWEBDEV - Browser code
WINDEV Mobile
AndroidAndroid Widget iPhone/iPadApple WatchUniversal Windows 10 AppWindows Mobile
Others
Stored procedures
Positions on the first file record according to a browse item. The record is read and the HFSQL variables are updated (Customer.Name for example, which means the Name item of Customer file).
The reading is performed from the lowest value to the greatest value of the browse item (see remarks for more details).
In most cases, <Source>.ReadFirst is used to set the position in the data file in order to perform a read loop with <Source>.ReadNext.
Several cases may occur after the call to <Source>.ReadFirst:
  • the data file is empty or no record corresponds to the filter (defined by <Source>.Filter): no reading is performed and <Source>.Out returns True.
  • the function tries to read a record that is already locked in read mode: no reading is performed, HErrorLock returns True and <Source>.Out returns True.
    Windows Mobile The management of locks is only performed on HFSQL Client/Server data files or data files handled by a native access. An HFSQL Mobile record cannot be locked. Indeed, the operating system of Pocket PC does not allow you to lock records.
    PHP The management of locks is not available.
    Java Access by JDBC: The management of locks is not available for databases accessed by JDBC.
This function can be used with the data files, HFSQL views or queries.
Versions 15 and later
Android This function is now available for Android applications.
New in version 15
Android This function is now available for Android applications.
Android This function is now available for Android applications.
Versions 17 and later
iPhone/iPad This function is now available for iPhone/iPad applications.
New in version 17
iPhone/iPad This function is now available for iPhone/iPad applications.
iPhone/iPad This function is now available for iPhone/iPad applications.
Versions 18 and later
Android Widget This function is now available in Android Widget mode.
Universal Windows 10 App This function is now available in Windows Store apps mode.
New in version 18
Android Widget This function is now available in Android Widget mode.
Universal Windows 10 App This function is now available in Windows Store apps mode.
Android Widget This function is now available in Android Widget mode.
Universal Windows 10 App This function is now available in Windows Store apps mode.
Remark: From version 19, HFSQL is the new name of HyperFileSQL.
Versions 21 and later
Universal Windows 10 App This function is now available in Universal Windows 10 App mode.
New in version 21
Universal Windows 10 App This function is now available in Universal Windows 10 App mode.
Universal Windows 10 App This function is now available in Universal Windows 10 App mode.
Example
Customer.ReadFirst(Name)
WHILE Customer.Out() = False
// Process the record
Customer.ReadNext(Name)
END
Syntax
<Result> = <Source>.ReadFirst([<Browse item> [, <Options>]])
<Result>: Boolean
Corresponds to:
  • False if an error occurred. In this case, HError returns an integer other than 0. HErrorInfo returns more details about the error. The record is not read.
  • the value of <Source>.Found in the other cases (the record can be read, even if <Result> returns False).
<Source>: Type corresponding to the specified source
Name of data file, HFSQL view or query used.
<Browse item>: Optional character string (with or without quotes)
Name of item used to browse the data file or view (this parameter is ignored by the queries). If this name is not specified, <Source>.ReadFirst will use:
  • For a data file: the last browse item used on this file by the last function for HFSQL management (starting with the letter H). If this item does not exist, the best browse item is automatically used.
  • For a query: the ORDER BY of query if it exists, otherwise the last item used.
  • For a view: the sort item of view (if it exists), otherwise the last item used.
<Options>: Optional constant
Used to configure:
  • the lock performed on the record read by <Source>.ReadFirst
  • whether the filter that was defined must be taken into account.
hLockNoNo lock (even if HStartLock was called): the record can be read or modified by another application during the reading.
PHP This constant is not available.

Java Access by JDBC: This constant is not available.
hLockWriteLock in write mode: the record currently read can be read by another application but it cannot be modified by another application.
PHP This constant is not available.

Java Access by JDBC: This constant is not available.
hLockReadWriteLock in read/write: the record currently read cannot be read or modified by another application.
OLE DB Lock in write-only. Operating mode equivalent to the hLockWrite constant.

PHP This constant is not available.

Java Access by JDBC: This constant is not available.
Versions 17 and later
hForwardOnly
New in version 17
hForwardOnly
hForwardOnly
Native Connectors (Native Accesses) This constant can only be used with Native Connectors.
Used to speed up the browse of data during a simple browse that does not use the following features:
  • Reading the previous record.
  • Modifying a record.
  • Saving position.
If one of these features is used, the result may differ from the expected one.
This constant can be used for example during a browse used to fill a memory table.
hKeepFilterThe filter implemented by <Source>.Filter will be taken into account, even if the search key is not optimized for the filter. Reminder: <Source>.Filter returns the search key optimized for the filter.
Caution: in this case, performance issues may arise for large files.
Hyper File 5.5 This constant cannot be used.
hNoRefresh
OLE DBNative Connectors (Native Accesses) <Source>.ReadFirst does not refresh the content of the table or query. If possible, the query is not re-run. All the saved positions are stored.
Windows Mobile Locks are managed only on HFSQL Client/Server data files or on data files handled by a Native Connector. An HFSQL Mobile record cannot be locked. Indeed, the operating system of Pocket PC does not allow you to lock records.
OLE DBNative Connectors (Native Accesses) The lock options will have no effect if the locks are not supported by the OLE DB provider or by the Native Connector.
OLE DB The lock mode specified by <Source>.ReadFirst will remain effective during the calls to <Source>.ReadPrevious and <Source>.ReadNext.
To modify the lock mode, you must use:
Native Connectors (Native Accesses) For Native Oracle Connector, a different lock mode can be specified for each record. However, if a transaction was started by SQLTransaction before setting the lock, the lock will only be released at the end of the transaction (SQLTransaction associated with sqlCommit or sqlRollBack).
Hyper File 5.5 The lock options are ignored. Use the locking read functions (HReadFirstLock) kept for backward compatibility.
PHP The lock options are not available.
Java Access by JDBC: The management of locks is not available for databases accessed by JDBC.
Remarks

Browse item

If the browse item is a key, <Source>.ReadFirst reads the record with the lowest key value. The sort order is the one that was specified in the analysis for this key. If duplicates are found, <Source>.ReadFirst reads the first "duplicate" record according to the sequence of record numbers.
If the browse item is not a key, <Source>.ReadFirst reads the first active record. When browsing the file, the records will be sorted according to their record number.
In this case, the selected browse item will appear in red in the code editor and a warning will appear in the "Code" pane.
Remark: The automatic completion proposes the key items only.
WINDEVWEBDEV - Server codeWINDEV MobileOLE DBNative Connectors (Native Accesses)

Browsing queries

By default, <Source>.ReadFirst re-runs the query to refresh the result. To avoid re-running the query, we recommend that you use the hNoRefresh constant.
Browsing a query run with the hQueryWithoutCorrection constant:
To browse the records in the order returned by the database, there is no need to specify a browse item. Example:
MyQuery.ExecuteQuery(hQueryWithoutCorrection)
...
MyQuery.ReadFirst(hNoRefresh)
If a browse item is specified, the query result is retrieved and indexed in its entirety. The browse is performed on the specified item. The initial sort of the query (specified by ORDER BY) is ignored. The created index (in HFSQL format) is sensitive to the case, to the punctuation, to the accented characters and in ascending order.
Example:
MyQuery.ExecuteQuery(hQueryWithoutCorrection)
...
MyQuery.ReadFirst(MyItem, hNoRefresh)
The created index is used to perform searches on the query result.
WINDEVWEBDEV - Server codeReports and QueriesiPhone/iPadUniversal Windows 10 AppWindows MobileAjaxUser code (UMC)External languageHFSQLHFSQL Client/ServerStored proceduresHyper File 5.5OLE DBNative Connectors (Native Accesses)

Locks

By default (<Options> not specified), the record is not locked.
If a lock is requested (hLockWrite or hLockReadWrite constant), the record will be read only if this record is not already locked.
There is no need to specify a lock parameter if the data file is locked by HStartLock: the lock specified by HStartLock is automatically taken into account. To ignore the lock specified by HStartLock, use the hLockNo constant.
OLE DBNative Connectors (Native Accesses) The lock options will have no effect if the locks are not supported by the OLE DB provider or by the Native Connector.

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 reading.
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).

Password

If <Source>.ReadFirst is the first function that handles the specified data file, the password is checked when opening the data file. If the password is incorrect, HErrorPassword returns True and <Source>.Out returns True.
WINDEVWEBDEV - Server codeReports and QueriesWindowsUser code (UMC)Stored proceduresNative Connectors (Native Accesses)

Native XML Connector

The behavior of <Source>.ReadFirst depends on <Source>.ActivateAutoFilter/<Source>.DeactivateAutoFilter.
<Source>.ActivateAutoFilter is enabled by default.
Therefore, to read the content of XML file, read the content of main file (the parent) then read the content of linked files (the children).
When reading a data file, a filter is automatically applied to the linked data files in order to only read the records corresponding to the main file.
For example:
The email of this person can be retrieved when browsing the Person file.
To do so, simply set the position on the "Person" file and apply <Source>.ReadFirst to the "Email" file.
In this case, the record read in the "Email" file will correspond to the first email associated with the current record in the "Person" file.
If this mechanism is disabled (<Source>.DeactivateAutoFilter), the record read in the "Email" file will correspond to the first record found in the Email file (and not to the child of the record read in the "Person" file).

Miscellaneous

Component : wd250hf.dll
Minimum version required
  • Version 25
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