honeysql/doc/general-reference.md
2021-04-09 18:06:57 -07:00

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General Reference Documentation

This section provides more details about specific behavior in HoneySQL and how to generate certain SQL constructs.

SQL Entity Generation

See #313

Tuples and Composite Values

Some databases support "composite values" which are usually represented as tuples in SQL, eg., (col1,col2) or (13,42,'foo'). In HoneySQL v1, you could sometimes get away with just using a vector of entities and/or values, but it was very much dependent on the context. HoneySQL v2 always treats vectors (and sequences) as function calls (which may be "special syntax" or an actual function call).

HoneySQL provides :composite as special syntax to construct these tuples:

(sql/format-expr [:composite :col1 :col2])
;;=> ["(col1, col2)"]
(sql/format-expr [:composite 13 42 "foo"])
;;=> ["(?, ?, ?)" 13 42 "foo"]
;; or using symbols:
(sql/format-expr '(composite col1 col2))
;;=> ["(col1, col2)"]
(sql/format-expr '(composite 13 42 "foo"))
;;=> ["(?, ?, ?)" 13 42 "foo"]

Other Sections Will Be Added!

Other Reference Documentation

The full list of supported SQL clauses is documented in the Clause Reference. The full list of operators supported (as prefix-form "functions") is documented in the Operator Reference section. The full list of "special syntax" functions is documented in the Special Syntax section. The best documentation for the helper functions is in the honey.sql.helpers namespace. If you're migrating to HoneySQL 2.0, this overview of differences between 1.0 and 2.0 should help.