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Apply #85 to the migration guide too

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Sean Corfield 2020-01-17 10:44:59 -08:00
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doc/migration-from-clojure-java-jdbc.md
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@ -12,7 +12,7 @@ This page attempts to list all of the differences between [clojure.java.jdbc](ht
`clojure.java.jdbc` returned result sets (and generated keys) as hash maps with simple, lower-case keys by default. `next.jdbc` returns result sets (and generated keys) as hash maps with qualified, as-is keys by default: each key is qualified by the name of table from which it is drawn, if known. The as-is default is chosen to a) improve performance and b) not mess with the data. Using a `:builder-fn` option of `next.jdbc.result-set/as-unqualified-maps` will produce simple, as-is keys. Using a `:builder-fn` option of `next.jdbc.result-set/as-unqualified-lower-maps` will produce simple, lower-case keys -- the most compatible with `clojure.java.jdbc`'s default behavior.
> Note: `clojure.java.jdbc` would make column names unique by appending numeric suffices, for example in a `JOIN` that produced columns `id` from multiple tables. `next.jdbc` does not do this: if you use _qualified_ column names -- the default -- then you would get `:sometable/id` and `:othertable/id`, but with _unqualified_ column names you would just get one `:id` in each row. It was always poor practice to rely on `clojure.java.jdbc`'s renaming behavior and it added quite an overhead to result set building, which is why `next.jdbc` does not support it -- use explicit column aliasing in your SQL instead if you want _unqualified_ column names!
> Note: `clojure.java.jdbc` would make column names unique by appending numeric suffixes, for example in a `JOIN` that produced columns `id` from multiple tables. `next.jdbc` does not do this: if you use _qualified_ column names -- the default -- then you would get `:sometable/id` and `:othertable/id`, but with _unqualified_ column names you would just get one `:id` in each row. It was always poor practice to rely on `clojure.java.jdbc`'s renaming behavior and it added quite an overhead to result set building, which is why `next.jdbc` does not support it -- use explicit column aliasing in your SQL instead if you want _unqualified_ column names!
If you used `:as-arrays? true`, you will most likely want to use a `:builder-fn` option of `next.jdbc.result-set/as-unqualified-lower-arrays`.