DbServer Methods (Typed)

DbServer.Append Method

DbServer.AppendDB Method (Typed)

DbServer.AppendDelimited Method (Typed)

DbServer.AppendSDF Method (Typed)

DbServer.Average Method (Typed)

DbServer.BLOBDirectExport Method

DbServer.BLOBDirectGet Method (Typed)

DbServer.BLOBDirectImport Method

DbServer.BLOBDirectPut Method (Typed)

DbServer.BLOBExport Method

DbServer.BLOBGet Method (Typed)

DbServer.BLOBImport Method (Typed)

DbServer.BLOBRootGet Method (Typed)

DbServer.BLOBRootLock Method (Typed)

DbServer.BLOBRootPut Method (Typed)

DbServer.BLOBRootUnlock Method (Typed)

DbServer.ClearFilter Method (Typed)

DbServer.ClearIndex Method (Typed)

DbServer.ClearLocate Method (Typed)

DbServer.ClearOrderScope Method (Typed)

DbServer.ClearRelation Method (Typed)

DbServer.ClearScope Method (Typed)

DbServer.Close Method (Typed)

DbServer.Commit Method (Typed)

DbServer.ConstructUniqueAlias Method (Typed)

DbServer.Continue Method (Typed)

DbServer.CopyDB Method (Typed)

DbServer.CopyDelimited Method (Typed)

DbServer.CopySDF Method (Typed)

DbServer.CopyStructure Method

DbServer.Count Method (Typed)

DbServer.CreateIndex Method (Typed)

DbServer.CreateOrder Method (Typed)

DbServer.DataField Method (Typed)

DbServer.Delete Method

DbServer.DeleteAll Method (Typed)

DbServer.DeleteOrder Method (Typed)

DbServer.Error Method (Typed)

DbServer.Eval Method (Typed)

DbServer.FieldGet Method (Typed)

DbServer.FieldGetBytes Method (Typed)

DbServer.FieldGetFormatted Method (Typed)

DbServer.FieldHyperLabel Method (Typed)

DbServer.FieldInfo Method (Typed)

DbServer.FieldName Method (Typed)

DbServer.FieldPos Method (Typed)

DbServer.FieldPut Method (Typed)

DbServer.FieldPutBytes Method (Typed)

DbServer.FieldSpec Method (Typed)

DbServer.FieldStatus Method (Typed)

DbServer.FieldSym Method (Typed)

DbServer.FieldValidate Method (Typed)

DbServer.FLock Method (Typed)

DbServer.GetArray Method (Typed)

DbServer.GetLocate Method (Typed)

DbServer.GetLookupTable Method (Typed)

DbServer.GoBottom Method (Typed)

DbServer.GoTo Method (Typed)

DbServer.GoTop Method (Typed)

DbServer.IndexKey Method (Typed)

DbServer.IndexOrd Method (Typed)

DbServer.Info Method (Typed)

DbServer.Join Method (Typed)

DbServer.Locate Method (Typed)

DbServer.LockCurrentRecord Method (Typed)

DbServer.LockSelection Method (Typed)

DbServer.NoIVarGet Method (Typed)

DbServer.NoIVarPut Method (Typed)

DbServer.Notify Method (Typed)

DbServer.OrderDescend Method

DbServer.OrderInfo Method (Typed)

DbServer.OrderIsUnique Method

DbServer.OrderKeyAdd Method

DbServer.OrderKeyCount Method

DbServer.OrderKeyDel Method

DbServer.OrderKeyGoTo Method (Typed)

DbServer.OrderKeyNo Method

DbServer.OrderScope Method (Typed)

DbServer.OrderSkipUnique Method (Typed)

DbServer.Pack Method (Typed)

DbServer.RddInfo Method (Typed)

DbServer.Recall Method (Typed)

DbServer.RecallAll Method (Typed)

DbServer.RecordInfo Method (Typed)

DbServer.Refresh Method (Typed)

DbServer.Reindex Method (Typed)

DbServer.Relation Method (Typed)

DbServer.Replace Method (Typed)

DbServer.ResetNotification Method (Typed)

DbServer.RLock Method (Typed)

DbServer.RLockVerify Method (Typed)

DbServer.Seek Method

DbServer.Select Method (Typed)

DbServer.SetDataField Method (Typed)

DbServer.SetFilter Method (Typed)

DbServer.SetIndex Method

DbServer.SetOrder Method

DbServer.SetOrderCondition Method (Typed)

DbServer.SetRelation Method (Typed)

DbServer.SetSelectiveRelation Method (Typed)

DbServer.Skip Method (Typed)

DbServer.Sort Method

DbServer.Sum Method (Typed)

DbServer.SuspendNotification Method (Typed)

DbServer.Total Method (Typed)

DbServer.UnLock Method (Typed)

DbServer.Update Method

DbServer.Zap Method (Typed)

DbServer.BLOBGet Method (Typed)

Get the contents of a BLOB, identified by its memo field number.

Namespace: XSharp.VO.SDK
Assembly: XSharp.VORDDClasses (in XSharp.VORDDClasses.dll) Version: 2.21

Syntax

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 VIRTUAL METHOD BLOBGet(
	uField AS USUAL,
	nStart AS LONG,
	nCount AS LONG
) AS USUAL

public virtual Usual BLOBGet(
	Usual uField,
	int nStart,
	int nCount
)

Request Example View Source

Parameters

uField: Type: Usual
The name, number, or symbol representing the position of the field in the database file structure.
nStart: Type: Long
The starting position in the memo field of the BLOB data. If nStart is positive, the starting position is relative to the leftmost character in uFieldPos. If nStart is negative, it is relative to the rightmost character in uFieldPos. If nStart is omitted, it is assumed to be 1.
nCount: Type: Long
The number of bytes of data to retrieve, beginning at nStart. If nCount is larger than the amount of data stored, excess data is ignored. If omitted, DBServer:BLOBGet() retrieves to the end of the data.

Return Value

Type: Usual
The BLOB data retrieved from the memo field. The data type of the return value depends on the actual data stored. Use ValType() or UsualType() to determine the data type. If the indicated field is not a memo field, DBServer:BLOBGet() returns NIL.

Remarks

Tip
nStart and nCount apply to string data only. They are ignored for any other data types.

DBServer:BLOBGet() is very similar to DBServer:FieldGet(). However, because string type variables cannot be larger than 64KB, DBServer:FieldGet() will raise a runtime error when attempting to retrieve memo fields of this magnitude or greater. DBServer:BLOBGet() will also raise an error if you attempt to retrieve a field greater than this magnitude; however, you can retrieve any subset of the BLOB data by using an nCount less than 64KB.

Tip
BLOB data less than 64KB can be retrieved from a memo field using standard means (for example, referring to the field by name in an expression or using the DBServer:FieldGet() method).

Examples

This example imports information from a word processing document into a field, then uses DBServer:BLOBGet() to extract the first 25 characters of the field:

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 1FUNCTION GetFirst25()
 2LOCAL nPos
 3LOCAL cStr AS STRING
 4LOCAL oDBCust := Customer{}
 5oDBCust := Customer{}
 6// Field that contains word processor documentation
 7nPos := oDBCust:FieldPos("WP_DOC")
 8// Import a file (can be larger than 64 KB), then obtain the
 9// first 25 characters to show to the user
10IF oDBCust:BLOBImport(nPos, "c:\app\temp.doc")
11cStr := oDBCust:BLOBGet(nPos, 1, 25)
12ELSE
13cStr := "Error: could not import file!"
14ENDIF
15oDBCust:Close()
16RETURN cStr

Reference

DbServer Class

XSharp.VO.SDK Namespace