The most difficult case to handle is when records are actually deleted from the source database between script executions. The following conditions apply:
· The data source can be any database.
· QlikView loads records inserted into the database or updated in the database after the last script execution.
· QlikView removes records deleted from the database after the last script execution.
· A field ModificationDate (or similar) is required for QlikView to recognize which records are new.
· A primary key field is required for QlikView to sort out updated records from the QVD file.
· This solution will force the reading of the QVD file to "standard mode" (rather than "super-fast mode"), which is still considerably faster than loading the entire database.
Script example:
Let ThisExecTime = Now( );
QV_Table:
SQL SELECT PrimaryKey, X, Y FROM DB_TABLE
WHERE ModificationTime >= #$(LastExecTime)#
AND ModificationTime < #$(ThisExecTime)#;
Concatenate LOAD PrimaryKey, X, Y FROM File.QVD
WHERE NOT EXISTS(PrimaryKey);
Inner Join SQL SELECT PrimaryKey FROM DB_TABLE;
If ScriptErrorCount = 0 then
STORE QV_Table INTO File.QVD;
Let LastExecTime = ThisExecTime;
End If
