QlikView Reference Manual.pdf - QlikCommunity - QlikView

Script Example:
QV_Table:
SQL SELECT PrimaryKey, X, Y FROM DB_TABLE
WHERE ModificationTime >= #$(LastExecTime)#;
Concatenate LOAD PrimaryKey, X, Y FROM File.QVD
WHERE NOT Exists(PrimaryKey);
STORE QV_Table INTO File.QVD;
Case 4: Insert, Update and Delete
The most difficult case to handle is when records are actually deleted from the source database between
script executions. The following conditions apply:
398
l The data source can be any database.
l QlikView loads records inserted into the database or updated in the database after the last script execution.
l QlikView removes records deleted from the database after the last script execution.
l A field ModificationDate (or similar) is required for QlikView to recognize which records are new.
l A primary key field is required for QlikView to sort out updated records from the QVD file.
l 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.