[pgjones]

The presence of Absent removes the entire expression, and if that removal results in an empty clause (or group) it will remove that as well. For example if `a = Absent` `WHERE a = {a}` will remove everything, whereas `WHERE a = {a} AND b = {b}` will result in `WHERE b = {b}`.

> Do you support templating a sql tstring into an sql tstring for composition?

Yep

[jitl]

How do you know what the expression is though? Don’t you need to be parsing the SQL? If I have non standard SQL somewhere upstream in the text how does the parser cope?

[pgjones]

It does parse the SQL. At the moment an expression is defined as all the text between the appropriate separators given the clause.