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(ns clojureql.internal
(:import [java.sql Statement])
(:require
clojure.set
[clojure.java.jdbc.internal :as jdbcint]
[clojure.java.jdbc :as jdbc])
(:use [clojure.string :only [join split upper-case replace] :rename {join join-str replace replace-str}]
[clojure.core.incubator :only [-?> -?>>]]))
(defn upper-name [kw]
(-> kw name .toUpperCase))
(defn apply-aliases
"Takes a statement and a hashmap of aliases and returns
a statement with all aliases applied"
[stmt aliases]
[(reduce (fn [acc [old new]]
(.replaceAll acc old (-> (.split new "\\.") first)))
stmt aliases)])
(defn clean-sql [coll]
"For internal use only. Concats a collection of strings interposing spaces
between the items. Removes any garbage whitespace."
(loop [s (-> (join-str " " coll) .trim)]
(if-not (.contains s " ")
s
(recur (-> (.replace s " " " ")
(.replaceAll "\\( " "\\(")
(.replaceAll " \\)" "\\)"))))))
(defn assemble-sql [s & args]
"For internal use only. Works like format but cleans up afterwards"
(loop [s (-> (apply format s args) .trim)]
(if-not (.contains s " ")
s
(recur (.replace s " " " ")))))
(defn nskeyword
"Converts a namespace qualified keyword to a string"
[k]
(if (string? k)
k
(let [[kns nm] ((juxt namespace name) k)]
(if kns
(apply str (interpose "/" [kns nm]))
nm))))
(defn qualified? [c]
(.contains (nskeyword c) "."))
(defn add-tname
[tname colname]
(let [tname (if (map? tname)
(-> tname vals first)
tname)
colname (if (vector? colname)
(str (-> colname first nskeyword) " AS " (-> colname last nskeyword))
colname)]
(if (qualified? colname)
(nskeyword colname)
(-> (str (if (or (keyword? tname)
(not (empty? tname)))
(str (nskeyword tname) \.) "")
(nskeyword colname))
(.replaceAll "\\.\\." "\\.")))))
(defn aggregate? [c]
(let [c (if (vector? c) (first c) c)]
(or (and (string? c) (.contains c "(")) ; Best guess
(and (keyword? c)
(not-any? nil? ((juxt namespace name) (keyword c)))))))
(defn split-fields [t a]
(->> (.split a ":")
(map #(if (= % "*")
"*"
(if (.contains % ".")
(str %)
(str t %))))
(interpose ",")
(apply str)))
(defn rename-subselects [tname tcols]
(let [tcols (mapcat #(.split % ",") tcols)
tname (if (map? tname)
(str (nskeyword (-> tname vals last)) ".")
(str (nskeyword tname) "_subselect."))]
(map #(let [col (nskeyword %)]
(if (.contains col ".")
(let [[name col] (.split col "\\.")]
(str tname col))
(str tname col)))
(remove aggregate? tcols))))
;TODO: This function is too complex. First step to simplyfing is getting rid
; of the support for a non-collection argument.
(defn to-orderlist
"Converts a list like [:id#asc :name#desc] to \"id asc, name desc\"
Also takes a single keyword argument. Does not qualify fields found
in aggregates. aggregates can also be a keyword in which case all
fields are left unqualified."
[tname aggregates fields]
(->> (if (coll? fields) fields [fields])
(map #(if (.contains (name %) "#")
(->> (.split (name %) "#")
((juxt first last))
(map (fn [f] (if (or (= f "asc") (= f "desc"))
(upper-case f)
(if (or (keyword? aggregates)
(some (fn [i] (= (nskeyword i) (nskeyword f))) aggregates))
f
(add-tname tname f)))))
(interpose " ")
(apply str))
(if (or (keyword? aggregates)
(some (fn [i] (= (nskeyword i) (nskeyword %))) aggregates))
(str (nskeyword %) " ASC")
(str (if (keyword? %) (add-tname tname %) %) " ASC"))))
(interpose ",")
(apply str)))
(declare to-name)
(defn to-tablename
[c]
(cond
(nil? c) nil
(keyword? c) (to-name c)
(string? c) c
:else ; Map denotes rename
(let [[orig new] (map name (first c))]
(str orig \space new))))
(defn to-name
" Converts a keyword to a string, checking for aggregates
(to-name :avg/y) => 'avg(y)'
(to-name :y) => 'y'
(to-name :parent :fn/field => 'fn(master.field)' "
([c] (to-name :none c))
([p c]
(let [p (if (= :none p) "" (str (to-tablename p) \.))]
(if (string? c)
(str "'" c "'")
(if (aggregate? c)
(let [[aggr col] (-> (nskeyword c) (.split "/"))]
(str aggr "(" (split-fields p col) ")"))
(add-tname p c))))))
(defn to-tablealias
"Returns the alias of a :tname. If :tname is not aliased it
returns the same as to-tablename."
[c]
(if (map? c)
(name (first (vals c)))
(to-tablename c)))
(defn emit-case
[{:keys [alias clauses returns else]}]
(format "CASE %s %s END AS %s"
(reduce #(str %1 (format " WHEN %s THEN ?" %2))
"" clauses)
(if else " ELSE ?" "")
(nskeyword alias)))
(defn to-fieldlist
"Converts a column specification to SQL notation field list
:tble [:sum/k1 :k2 [:avg/k3 :as :c]] => 'sum(tble.k1),tble.k2,avg(tble.k3) AS c'
:tble :t1 [:avg/a:b] => 'avg(t1.a, t1.b)' "
([tcols] (to-fieldlist nil tcols))
([tname tcols]
(let [tname (if-let [tname (to-tablename tname)]
(str (-> tname (.split " ") last) \.) "")]
(letfn [(split-aggregate [item]
(let [item (nskeyword item)]
(if (.contains item "/")
(re-find #"(.*)\/(.*)" (nskeyword item))
(re-find #"(.*)\((.*)\)" item))))
(item->string [i]
(cond
(string? i) i ;User passed a string
(map? i) ;Used case
(emit-case i)
(vector? i) ;Either aliased or aggregated
(if (aggregate? (first i))
(let [[col _ alias] (map nskeyword i)
[_ fn aggr] (split-aggregate col)]
(if (string? (first i))
(str _ " AS " alias)
(str fn "(" (split-fields tname aggr) ")" " AS " alias)))
(let [[col _ alias] (map nskeyword i)]
(str (add-tname tname col) " AS " alias)))
(and (aggregate? i) (not (string? i)))
(let [[_ fn aggr :as x] (split-aggregate i)]
(str fn "(" (split-fields tname aggr) ")"))
(string? i)
i
:else
(add-tname tname i)))]
(cond
(not (coll? tcols))
tcols
(every? string? tcols)
(join-str "," tcols)
(= 1 (count tcols))
(-> tcols first item->string)
(or (keyword? tcols)
(and (>= 3 (count tcols))
(= :as (nth tcols 1))))
(item->string tcols)
:else (->> tcols (map item->string) (join-str \,)))))))
(defn has-aggregate?
[tble]
(some aggregate? (:tcols tble)))
(defn find-aliases
"Scans a column spec to find the first alias, if none is found the
first column is used instead"
[tcols]
(let [alias (-?>> (filter #(and (vector? %) (= 3 (count %))) tcols)
(map (comp name last)))]
(if (seq alias)
alias
[(-> tcols first nskeyword)])))
(defn find-aggregates
"Goes through tcols looking for vectors with 3 items and returns
the alias for those found."
[tcols]
; TODO: Dangerous, vector? should be table? and arguments reversed
(-?>> (if (vector? tcols) tcols (:tcols tcols))
(filter #(and (vector? %) (= 3 (count %))))
(map (comp name last))))
(defn requires-subselect?
[table]
(if (keyword? table)
false
(or (has-aggregate? table)
(number? (:limit table)) ; TODO: Check offset as well?
(seq (:restriction table))))) ; TODO: Sorting as well?
(defn extract-aliases
" Internal: Looks through the tables in 'joins' and finds tables
which requires subselects. It returns a vector of the
original name and the new name for each table "
[joins]
(for [[tbl-or-kwd pred] (map :data joins)
:when (requires-subselect? tbl-or-kwd)
:let [{:keys [tname tcols]} tbl-or-kwd
aliases (find-aliases tcols)]]
(into [(to-tablename tname)]
(map #(if (map? tname)
(str (-> tname vals last nskeyword) \. %)
(str (name tname) "_subselect." %)) aliases))))
(defn with-rename
"Renames fields that have had their parent aliased.
(name is horribly misleading, it protects against errors when
tables have been renamed)
:one [:one.a :one.b] {:one :two} => 'one AS one(a,b)' "
[tname tcols renames]
(let [oname (to-tablename tname)
unqualify (fn [s] (let [s (nskeyword s)]
(subs s (inc (.indexOf s ".")))))]
(if (map? renames)
(format "%s AS %s(%s)" oname oname
(reduce #(let [[orig new] %2]
(.replaceAll %1 (unqualify orig) (unqualify new)))
(join-str "," (->> (map nskeyword tcols)
(filter #(.contains % oname))
(map #(subs % (inc (.indexOf % "."))))))
renames))
(str oname "(" (to-fieldlist tcols) ")"))))
(defn get-foreignfield
"Extracts the first foreign field in a column spec
:t1 [:t1.x :t2x] => :t2.x "
[tname s]
(-> (remove #(.contains (-> % name (.split "\\.") first) (name tname)) s)
first))
(defn sql-clause [pred & args]
" Allows you to generate an sql clause by identifying params as %1, %2, %n.
(sql-clause '%1 > %2 < %1' 'one' 'two') => 'one > two < one' "
(letfn [(rep [s i] (.replaceAll s (str "%" (inc i))
(let [item (nth args i)]
(cond
(keyword? item) (name item)
(string? item) (str "'" item "'")
:else
(str item)))))]
(if (empty? args)
pred
(loop [i 0 retr pred]
(if (= i (-> args count dec))
(rep retr i)
(recur (inc i) (rep retr i)))))))
; SQL Specifics
(defn result-seq
"Creates and returns a lazy sequence of structmaps corresponding to
the rows in the java.sql.ResultSet rs. Accepts duplicate keys"
[^java.sql.ResultSet rs]
(let [rsmeta (.getMetaData rs)
idxs (range (.getColumnCount rsmeta))
keys (map (comp keyword
#(.toLowerCase ^String %)
#(.getColumnLabel rsmeta %)
inc)
idxs)
assoc-value (fn [mapping i]
(let [key (nth keys i)
val (.getObject rs ^Integer (inc i))]
; due to http://dev.clojure.org/jira/browse/CLJ-700
; we can't use contains? so use ::missing as a marker
(let [old (mapping key)]
(when-not (or (identical? ::missing old)
(= val old))
(throw (Exception.
(format "ResultSet has same label %s for different values, please rename one" key)))))
(assoc! mapping key val)))
empty (apply hash-map
(interleave (set keys)
(repeat ::missing)))
rows (fn rows []
(lazy-seq
(when (.next rs)
(cons
(persistent!
(reduce assoc-value
(transient empty)
idxs))
(rows)))))]
(rows)))
(defn with-results*
"Executes a query, then evaluates func passing in a seq of the results as
an argument. The first argument is a vector containing the (optionally
parameterized) sql query string followed by values for any parameters."
[[sql & params :as sql-params] func]
(when-not (vector? sql-params)
(throw (Exception. "sql-params must be a vector")))
(with-open [stmt (jdbc/prepare-statement (:connection jdbcint/*db*) sql)]
(doseq [[idx v] (map vector (iterate inc 1) params)]
(.setObject stmt idx v))
(if-let [fetch-size (-> jdbcint/*db* :opts :fetch-size)]
(do
(.setFetchSize stmt fetch-size)
(jdbc/transaction
(with-open [rset (.executeQuery stmt)]
(func (result-seq rset)))))
(with-open [rset (.executeQuery stmt)]
(func (result-seq rset))))))
(defn supports-generated-keys? [conn]
"Checks if the JDBC Driver supports generated keys"
(try (.supportsGetGeneratedKeys (.getMetaData conn))
(catch AbstractMethodError _ false)))
(defn prepare-statement [conn sql]
"When supported by the JDBC Driver, creates a new prepared statement which will return the generated keys - else returns a 'normal' prepared statement"
(if (supports-generated-keys? conn)
(jdbc/prepare-statement conn sql :return-keys true)
(jdbc/prepare-statement conn sql)))
(defn generated-keys [stmt]
"When supported by the JDBC driver, returns the generated keys of the latest executed statement"
(when (supports-generated-keys? (.getConnection stmt))
(let [ks (.getGeneratedKeys stmt)]
{:last-index
(and
(.next ks)
(.getObject ks 1))})))
(defn exec-prepared
"Executes an (optionally parameterized) SQL prepared statement on the
open database connection. Each param-group is a seq of values for all of
the parameters."
([sql param-group]
(with-open [stmt (prepare-statement (:connection jdbcint/*db*) sql)]
(doseq [[idx v] (map vector (iterate inc 1) param-group)]
(.setObject stmt idx v))
(jdbc/transaction
(let [retr (.execute stmt)]
(with-meta [(.getUpdateCount stmt)]
(generated-keys stmt))))))
([sql param-group & param-groups]
(with-open [stmt (jdbc/prepare-statement (:connection jdbcint/*db*) sql)]
(doseq [param-group (cons param-group param-groups)]
(doseq [[idx v] (map vector (iterate inc 1) param-group)]
(.setObject stmt idx v))
(.addBatch stmt))
(jdbc/transaction
(seq (.executeBatch stmt))))))
(defn conj-rows
"Inserts rows into a table with values for specified columns only.
column-names is a vector of strings or keywords identifying columns. Each
value-group is a vector containing a values for each column in
order. When inserting complete rows (all columns), consider using
insert-rows instead."
[table column-names & value-groups]
(let [column-strs (map to-tablename column-names)
n (count (first value-groups))
template (apply str (interpose "," (replicate n "?")))
columns (if (seq column-names)
(format "(%s)" (apply str (interpose "," column-strs)))
"")]
(apply exec-prepared
(format "INSERT INTO %s %s VALUES (%s)"
(to-tablename table) columns template)
value-groups)))
(defn update-vals
"Updates values on selected rows in a table. where-params is a vector
containing a string providing the (optionally parameterized) selection
criteria followed by values for any parameters. record is a map from
strings or keywords (identifying columns) to updated values."
[table where-params record]
(let [[where & params] where-params
column-strs (map to-tablename (keys record))
columns (apply str (concat (interpose "=?, " column-strs) "=?"))]
(exec-prepared
(format "UPDATE %s SET %s WHERE %s"
(to-tablename table) columns where)
(concat (vals record) params))))
(defn update-or-insert-vals
"Updates values on selected rows in a table, or inserts a new row when no
existing row matches the selection criteria. where-params is a vector
containing a string providing the (optionally parameterized) selection
criteria followed by values for any parameters. record is a map from
strings or keywords (identifying columns) to updated values."
[table where-params record]
(jdbc/transaction
(let [result (update-vals table where-params record)]
(if (zero? (first result))
(conj-rows table (keys record) (vals record))
result))))
(defn table-alias
"given an RTable tname, which is either
- a simple table-name string
- a {:table-name :alias} map
return
in the case of the simple string, the string itself
in the case of the alias map, the value of the explicit alias"
[tname]
(if (map? tname)
(str (nskeyword (-> tname vals last)))
(nskeyword tname)))
(defn subselect-table-alias
"given an RTable tname, which is either
- a simple table-name string
- a {:table-name :alias} map
return
in the case of the simple string, the string with _subselect appended
in the case of the alias map, the value of the explicit alias"
[tname]
(if (map? tname)
(str (nskeyword (-> tname vals last)))
(str (nskeyword tname) "_subselect")))
(defn join-table-alias
"given tna from the first position of the :data value of a join definition,
which is one of
- an RTable (for subselects)
- a simple table-name
- a space separated \"table-name alias\" pair
return
- if the object was an RTable, return the subselect table
alias, which is either an explicit alias, or
(str (nskeyword (:tname tna)) \"_subselect\")
- if the object was a simple table-name, return it
- if the object was an aliased table-name, return
just the alias"
[tna]
(if (map? tna)
(subselect-table-alias (:tname tna))
(let [[table-name alias] (split tna #"\s+")]
(or alias table-name))))
(defn joins-by-table-alias
"given a list of joins return a map of joins
keyed by the join table-alias or,
in the case of subselects, the subselect table alias"
[joins]
(reduce #(let [{[table-name-alias join-on] :data :as join} %2
k (join-table-alias table-name-alias)]
(assoc %1 k join))
{}
joins))
(defn join-column-names
"given table-name-alias from the first position of the :data value of a join def,
if table-name-alias is an RTable, representing a subselect, then return the renamed
join cols according the the subselect alias. if table-name-alias is not an
RTable then return cols unmodified"
[table-name-alias cols]
(if (map? table-name-alias)
(let [otn (table-alias (:tname table-name-alias))
sstn (subselect-table-alias (:tname table-name-alias))
otn-patt (re-pattern (str otn "\\..*"))
col-strs (map nskeyword cols)
subselect-col-strs (filter #(re-matches otn-patt %) col-strs)
other-col-strs (filter #(not (re-matches otn-patt %)) col-strs)
renamed-subselect-col-strs (map #(replace-str % (re-pattern (str otn "\\.")) (str sstn "."))
subselect-col-strs)]
(concat renamed-subselect-col-strs other-col-strs))
cols))
(defn to-tbl-name
"given a join definition, return a table alias
that the join depends on"
[{[table-name-alias join-on] :data :as join}]
(->> join-on :cols
(join-column-names table-name-alias)
(map #(-> % name (.replaceAll "\\..*" "")))
(filter #(not= % (join-table-alias table-name-alias)))
first))
(defn to-graph-el
"given a join definition return an edge in the table
alias dependency graph"
[m {[table-name-alias join-on] :data :as join}]
(let [required-table (to-tbl-name join)]
(assoc m (join-table-alias table-name-alias) required-table)))
(defn add-deps
"recursively add dependencies of tbl into a list"
[map-of-joins edges tbl]
(into [(map-of-joins tbl)] (map #(add-deps map-of-joins edges %)
(filter #(= tbl (edges %))
(keys edges)))))
(defn flatten-deps
[map-of-joins edges set-of-root-nodes]
(filter #(not (nil? %)) (flatten (map #(add-deps map-of-joins edges %) set-of-root-nodes))))
(defn sort-joins
"sort a list of joins into dependency order"
[joins]
(let [map-of-joins (joins-by-table-alias joins)
edges (reduce to-graph-el {} joins)
set-of-root-nodes (clojure.set/difference (into #{} (vals edges)) (into #{} (keys edges)))]
(flatten-deps map-of-joins edges set-of-root-nodes)))
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