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As Wikipedia defines FLWOR is an acronym: FOR, LET, WHERE, ORDER BY, RETURN. FLWOR is loosely analogous to SQL’s SELECT-FROM-WHERE. FLWOR expressions can be used in OSB.

If we are creating variables in assign actions for just intermediate XQuery expressions evaluation then ‘let’ can be used multiple assign actions into one to increase proxy service performance.

In the following screenshot, 1st assign action loads contents XQuery resource and stores it in ‘varConfigPayload’ variable. The 2nd assign action gets the proxy name sent in payload using ‘$body/Payload/ProxyName/text()’ and stores it in ‘varProxyName’ variable. And the 3rd assign activity uses ‘$varConfigPayload/ProxyService[@name=$varProxyName]/Flag/text()’ to get the value from XQuery resource and store it in ‘varFlagValue’ variable.

Assume that variable ‘varProxyName’ is not used anywhere else, then we can combine the 2nd and 3rd assign actions by giving the expression as shown in below screenshot.

This is how we can use the FLWOR expressions to combine multiple assign activities into one.