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  • Browse item
  • Browsing queries
  • Locks
  • Memos
  • Password
  • Native XML Connector
  • Miscellaneous
WINDEV
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WEBDEV
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WINDEV Mobile
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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).
Values in the browse item are read in ascending order (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 read operation is performed, HErrorLock returns True and <Source>.Out returns True.
    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
Name of item used to loop through 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 the view (if it exists), otherwise the last item used.
<Options>: Optional constant
Used to configure:
  • the lock set on the record read by <Source>.ReadFirst
  • whether the filter that was defined must be taken into account.
Versions 17 and later
hForwardOnly
New in version 17
hForwardOnly
hForwardOnly
Native Connectors (Native Accesses) This constant can only be used with Native Connectors.
Optimizes simple iterations that do 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.
For example, this constant can be used to populate a Table control programmatically.
hKeepFilterThe filter set 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.
hLockNoNo lock: 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.
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.
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.
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.
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 with the sqlCommit or sqlRollBack constant).
Hyper File 5.5 The lock options are ignored. Use 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 be displayed 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-executes the query to refresh the result. To avoid re-executing 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 iteration 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 QueriesUniversal Windows 10 AppiPhone/iPadUser code (UMC)External languageAjaxHFSQLHFSQL 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.
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 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).

Password

If <Source>.ReadFirst is the first function that handles the specified data file, the password is checked when the opening 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

  • The current record number is returned by <Source>.RecNum.
  • <Source>.ChangeKey is used to modify the search key while remaining positioned on the current record.
  • To improve the first browse times on a file, use <Source>.Optimize on this data file.
  • This function replaces HReadFirstLock and HReadFirstNoLock, which were kept for compatibility with WINDEV 5.5.
Component: wd270hf.dll
Minimum version required
  • Version 25
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