I have a function, parseQuery, that parses a SQL query into an abstract representation of that query.
I'm about to write a function that takes an abstract representation of a query and returns a SQL query string.
What should I call the second function?
Compose? When parsing a query you break it into its constituent parts (tokens, etc.), the reverse would be composing the parts into a string query.
I think "serialize" is probably the word you want. It means to produce a textual representation of data that can be exported (and imported) from the program.
flatten?
The parsed query object perhaps represents a condition hierarchy, which you are "flattening" back into a 1 dimensional string.
But given that you're going from object to string, really just use toString or toSQL() or something like that. Besides, if you designed it well and are using the right app, you can rename it later and just stick stuff in the comments on what it does.
Just to add some stuff.
Surely parse is a two way word.
You can parse an abstract into a query.
You can parse a query into an abstract.
The question should be, what do you name the latter part of the method, and because in this instance you're parsing an abstract to make a query you'd call it parseAbstract.
To answer the question, parsing has no opposite.
compose, construct, generate, render,condense, reduce, toSQL, toString depending on the nature of the class and its related operators
A traditional compiler has two parts: a parser and a code generator.
So you could call it "Generate". Of course, it's a little bit different here because the compiler isn't writing source code. (unless it's a precompiler).
+1 for Generate, but tack on what you're generating, i.e. GenerateSQL()
writeQuery. Parse is the act of reading it from a string and creating the object (let's say 'actual') representation. The opposite would be writing the object into a string.
I voted for 'compose' but if you don't like that I would also suggest 'build'
I'd say serialize and deserialize, instead of parse and ...
In compiler terminology, the opposite is "unparse". Specifically, parsing turns a stream of tokens into abstract syntax trees, while unparsing turns abstract syntax trees into a stream of tokens.
I would go for ToString(), since you can usually chain-nest them (opposite functions, that let you pass from Class1 to Class2 and vice-versa)
DateTime.Parse( DateTime.Parse( myDate.ToString() ).ToString() );
Serialize() looks like a nice choice, but it already has an opposite in Deserialize().
In your specific scenario, as other pointed out, ToSql() is another good choice.
I believe the answer you're looking for is: "Don't parse SQL or assemble SQL in the first place. Use an Object/Relational Mapper and stop wasting your employer's money by solving problems that have already been solved for quite some time."