(ns metabase.util.connection
(:require [clojure.set :as set]
[metabase.util :as u]
[toucan2.core :as t2])
(:import
(java.sql Connection DatabaseMetaData ResultSet ResultSetMetaData))) | |
(set! *warn-on-reflection* true) | |
(defn- consume-rset [^ResultSet rset cb]
(into {} (iteration
(fn [_]
(when (.next rset)
(cb rset)))))) | |
Returns a map of all column names to their respective type names for the given | (defn app-db-column-types
[app-db table-name']
(let [table-name (cond-> (name table-name')
(= (:db-type app-db) :h2) u/upper-case-en)]
(t2/with-connection [^Connection conn]
(let [md (.getMetaData conn)]
(with-open [cols (.getColumns md nil nil table-name nil)
pks (.getPrimaryKeys md nil nil table-name)
fks (.getImportedKeys md nil nil table-name)]
(let [pks (consume-rset pks (fn [^ResultSet pks]
[(.getString pks "COLUMN_NAME") true]))
fks (consume-rset fks (fn [^ResultSet fks]
[(.getString fks "FKCOLUMN_NAME")
(str (.getString fks "PKTABLE_NAME")
"."
(.getString fks "PKCOLUMN_NAME"))]))]
(consume-rset cols (fn [^ResultSet cols]
(let [col (.getString cols "COLUMN_NAME")]
[col {:type (.getString cols "TYPE_NAME")
:notnull (= (.getInt cols "NULLABLE")
ResultSetMetaData/columnNoNulls)
:pk (get pks col)
:fk (get fks col)}]))))))))) |
(defn- group-rset [^ResultSet rset cb]
(u/group-by first some? second (constantly true) conj #{}
(iteration (fn [_]
(when (.next rset)
(or (cb rset) [])))))) | |
Returns a map of the downstream relations that will have deletes cascade to them, for the given table. | (defn app-db-cascading-deletes
[app-db table-names]
(t2/with-connection [^Connection conn]
(let [md (.getMetaData conn)]
(reduce (partial merge-with set/union)
nil
(for [table-name' table-names]
(let [table-name (cond-> (name table-name')
(= (:db-type app-db) :h2) u/upper-case-en)]
(with-open [fks (.getImportedKeys md nil nil table-name)]
(group-rset fks (fn [^ResultSet fks]
(when (= (.getInt fks "DELETE_RULE") DatabaseMetaData/importedKeyCascade)
[(u/lower-case-en (.getString fks "PKTABLE_NAME"))
{:child-table (name table-name')
:child-column (u/lower-case-en (.getString fks "FKCOLUMN_NAME"))
:parent-column (u/lower-case-en (.getString fks "PKCOLUMN_NAME"))}])))))))))) |