/
core.clj
298 lines (249 loc) · 7.79 KB
/
core.clj
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
(ns datumbazo.driver.core
(:require [clojure.spec.alpha :as s]
[clojure.string :as str]
[datumbazo.error :as error]
[sqlingvo.core :as sql :refer [ast sql]])
(:import [java.sql Connection Savepoint]))
(defprotocol Connectable
(-connect [driver db opts])
(-connection [driver db])
(-disconnect [driver db]))
(defprotocol Executeable
(-execute-all [driver db sql opts])
(-execute-one [driver db sql opts]))
(defprotocol Preparable
(-prepare [driver db sql opts]))
(defprotocol Transactable
(-transact [driver db f opts]))
(defn- driver-namespace [db]
(symbol (str "datumbazo.driver." (name (:backend db)))))
(defmulti driver
"Find the driver for `db`."
(fn [db & [opts]]
(require (driver-namespace db))
(:backend db)))
(defn row-count
"Normalize into a record, with the count of affected rows."
[result]
[{:count
(if (sequential? result)
(first result)
result)}])
(defn savepoint?
"Return true if `x` is a java.sql.Savepoint, otherwise false."
[x]
(instance? Savepoint x))
(defn ^Connection connection
"Return the current connection to `db`."
[db]
(-connection (:driver db) db))
(s/fdef connection
:args (s/cat :db sql/db?))
(defn connected?
"Returns true if `db` is connected, otherwise false."
[db]
(some? (connection db)))
(s/fdef connected?
:args (s/cat :db sql/db?))
(defn connect
"Connect to `db` using `opts`."
[db & [opts]]
{:pre [(not (connected? db))]}
(update db :driver -connect db opts))
(s/fdef connect
:args (s/cat :db sql/db? :opts (s/? (s/nilable map?))))
(defn disconnect
"Disconnect from `db`."
[db & [opts]]
{:pre [(connected? db)]}
(update db :driver -disconnect db))
(s/fdef disconnect
:args (s/cat :db sql/db? :opts (s/? (s/nilable map?))))
(defn prepare
"Return a prepared statement for `sql`."
[db sql & [opts]]
{:pre [(connected? db)]}
(-prepare (:driver db) db sql opts))
(s/fdef prepare
:args (s/cat :db sql/db? :sql any? :opts (s/? (s/nilable map?))))
(defn transact
"Run `f` within a database transaction on `db`."
[db f & [opts]]
{:pre [(connected? db)]}
(-transact (:driver db) db f opts))
(s/fdef transact
:args (s/cat :db sql/db? :f ifn? :opts (s/? (s/nilable map?))))
(defn with-connection*
"Open a database connection, call `f` with the connected `db` as
argument and close the connection again."
[db f & [opts]]
(if (connected? db)
(f db)
(let [db (connect db opts)]
(try (f db)
(finally (disconnect db))))))
(s/fdef with-connection*
:args (s/cat :db sql/db? :f ifn? :opts (s/? (s/nilable map?))))
(defmacro with-connection
"Open a database connection, bind the connected `db` to `db-sym`,
evaluate `body` and close the connection again."
[[db-sym db & [opts]] & body]
`(with-connection* ~db (fn [~db-sym] ~@body) ~opts))
(defn with-transaction*
"Start a new `db` transaction call `f` with `db` as argument and
commit the transaction. If `f` throws any exception the transaction
gets rolled back."
[db f & [opts]]
{:pre [(connected? db)]}
(transact db f opts))
(s/fdef with-transaction*
:args (s/cat :db sql/db? :f ifn? :opts (s/? (s/nilable map?))))
(defmacro with-transaction
"Start a new `db` transaction, bind `db` to `db-sym` and evaluate
`body` within the transaction."
[[db-sym db & [opts]] & body]
`(with-connection [db# ~db]
(with-transaction* db# (fn [~db-sym] ~@body) ~opts)))
(defmacro with-rollback
"Start a transaction, evaluate `body` and rollback."
[[db-sym db] & body]
`(with-transaction [~db-sym ~db {:rollback-only true}]
~@body))
(defn commit!
"Commit the current database connection."
[db]
{:pre [(connected? db)]}
(.commit (connection db)))
(s/fdef commit!
:args (s/cat :db sql/db?))
(defn auto-commit?
"Returns true if the current database connection is in auto commit
mode, otherwise false."
[db]
{:pre [(connected? db)]}
(.getAutoCommit (connection db)))
(s/fdef auto-commit?
:args (s/cat :db sql/db?))
(defn set-auto-commit! [db auto-commit]
{:pre [(connected? db)]}
(.setAutoCommit (connection db) auto-commit))
(s/fdef set-auto-commit!
:args (s/cat :db sql/db? :auto-commit boolean?))
(defn rollback! [db & [savepoint]]
{:pre [(connected? db)]}
(if savepoint
(.rollback (connection db) savepoint)
(.rollback (connection db))))
(s/fdef rollback!
:args (s/cat :db sql/db? :savepoint (s/? (s/nilable savepoint?))))
(defn ^Savepoint set-savepoint!
"Set a savepoint on the current connection."
[db & [name]]
{:pre [(connected? db)]}
(if name
(.setSavepoint (connection db) name)
(.setSavepoint (connection db))))
(s/fdef set-savepoint!
:args (s/cat :db sql/db? :name (s/? (s/nilable string?))))
(defn release-savepoint!
[db savepoint]
{:pre [(connected? db)]}
(.releaseSavepoint (connection db) savepoint))
(s/fdef release-savepoint!
:args (s/cat :db sql/db? :savepoint savepoint?))
(defn with-savepoint*
[db f & [opts]]
(with-connection [db db]
(let [auto-commit (auto-commit? db)]
(set-auto-commit! db false)
(let [savepoint (set-savepoint! db)]
(try (f (assoc-in db [:driver :savepoint] savepoint))
(catch Exception e
(rollback! db savepoint)
(throw e))
(finally
(release-savepoint! db savepoint)
(set-auto-commit! db auto-commit)))))))
(s/fdef with-savepoint*
:args (s/cat :db sql/db? :f ifn? :opts (s/? (s/nilable map?))))
(defmacro with-savepoint
"Start a transaction, evaluate `body` and rollback."
[[db-sym db opts] & body]
`(with-savepoint* ~db (fn [~db-sym] ~@body) ~opts))
(defn sql-str
"Prepare `stmt` using the database and return the raw SQL as a string."
[stmt]
(let [ast (ast stmt)]
(with-connection [db (:db ast)]
(with-open [stmt (prepare db (sql ast))]
(if (.startsWith (str stmt) (str/replace (first (sql ast)) #"\?.*" ""))
(str stmt)
(throw (UnsupportedOperationException.
"Sorry, sql-str not supported by SQL driver.")))))))
(defn execute-sql-query
"Execute a SQL query."
[db sql & [opts]]
(with-connection [db db]
(try (-execute-all (:driver db) db sql opts)
(catch Exception error
(throw (error/sql-error error sql))))))
(s/fdef execute-sql-query
:args (s/cat :db sql/db? :sql any? :opts (s/? (s/nilable map?))))
(defn execute-sql-statement
"Execute a SQL statement."
[db sql & [opts]]
(with-connection [db db]
(try (-execute-one (:driver db) db sql opts)
(catch Exception error
(throw (error/sql-error error sql))))))
(s/fdef execute-sql-statement
:args (s/cat :db sql/db? :sql any? :opts (s/? (s/nilable map?))))
(defn- execute-fn
"Return the SQL execution fn for `ast`."
[ast]
(case (:op ast)
:create-table
execute-sql-statement
:delete
(if (:returning ast)
execute-sql-query
execute-sql-statement)
:except
execute-sql-query
:explain
execute-sql-query
:insert
(if (:returning ast)
execute-sql-query
execute-sql-statement)
:intersect
execute-sql-query
:select
execute-sql-query
:union
execute-sql-query
:update
(if (:returning ast)
execute-sql-query
execute-sql-statement)
:values
execute-sql-query
:with
(execute-fn (:query ast))
execute-sql-statement))
(defn execute
"Execute `stmt` against a database."
[stmt & [opts]]
(let [{:keys [db] :as ast} (ast stmt)]
(let [sql (sql ast)
exec-fn (execute-fn ast)]
(with-meta
(case (:op ast)
:create-table
(if (seq (rest sql))
;; TODO: sql-str only works with PostgreSQL driver
(exec-fn db [(sql-str stmt)] opts)
(exec-fn db sql opts))
(exec-fn db sql opts))
{:datumbazo/stmt stmt
:datumbazo/opts opts}))))