Programming Mechworks PDM > DBWCommandShell > Library Reference > Database

Description

Same as DBWGetStringFieldData1 but allowing to retrieve also NULL values as results

Syntax

Function DBWGetStringFieldData2(datasource, login, password, table, field_to_read,key, keyvalue, ByRef sResult, isValueNull)

Parameters

datasource	name of a valid datasource or "@USEDEFAULTDATASOURCE" to force the usage of the default application datasource as returned from constant DBWorksConnectionDSN
login	a valid login to access the datasource in an autheinticated way
password	the password related to the specified login.
table	name of an existing table in the specified datasource.
field_to_read	name of the field from which the value must be taken.
key	field of which the value will be checked to determine the query selection.
keyvalue	value that will be checked to determine which records to read.

Return values

sResult	the result of the query as a string
isValueNull	TRUE: if the returned field value is NULLFALSE: otherwise

The function returns:

TRUE	if the selection found any record matching the query
FALSE	otherwise

Remarks

Use this function to retrieve values from an ODBC linked database.
This command is equivalent to applying an SQL selection query such as "select " & field_to_read & " from " & table &" WHERE " & key &" ='" & keyvalue & "'".

When connecting through file DSN, it's mandatory to use the datasource declared as @USEDEFAULTDATASOURCE.

Example

Sub main()
DBWInit(TRUE)
datasource = "@USEDEFAULTDATASOURCE"
login = DBWorksConnectionUID
password = DBWorksConnectionPWD
table = DBWLookUp("NAME_DOCUMENT_TABLE")
field_to_set = DBWLookup("NAME_FIELD_DESCRIPTION")
Key = DBWLookup("NAME_FIELD_UNIQUE_ID")
keyvalue="1991"
field_to_read = DBWLookup("NAME_FIELD_DESCRIPTION")
res = DBWGetStringFieldData2(datasource, login, password, table, field_to_read, key, keyvalue, sResult, isValueNull)
DBWMsgbox "res=" & res & vbcrlf & "isValueNull=" & isValueNull & vbcrlf & "sResult=" & sResult
End Sub

Possible cases of return values:

	NULL record found	not NULL record found	no record found
res	TRUE	TRUE	FALSE
isValueNull	TRUE	FALSE	FALSE
sResult		string

DBWGetStringFieldData2