ebus-racket: rename db.plt->db.rkt

1 files changed, 37 insertions, 0 deletions

diff --git a/ebus-racket/db.rkt b/ebus-racket/db.rkt
new file mode 100644
index 0000000..14817e5
--- /dev/null
+++ b/ebus-racket/db.rkt
@@ -0,0 +1,37 @@
+#lang racket/base
+(require (prefix-in db: (planet ryanc/db:1:5)))
+
+(define pgc
+  (db:postgresql-connect #:user "ebus"
+                         #:database "ebus"
+                         #:password "ebus"
+                         #:server "10.2.2.26"))
+
+;; Query ID of sensor given by sensor-name
+;; Returns null if sensor is undefined
+(define (get-sensor-id sensor-name)
+  (with-handlers ([exn:fail?  (lambda (exn) (void))])
+    (db:query-value pgc "SELECT id FROM sensor WHERE name = $1" sensor-name)))
+
+;; Create Sensor-ID with given name
+;; returns id
+(define (create-sensor-id sensor-name)
+  (db:query-exec "INSERT INTO sensor(name) VALUES ($1)" sensor-name)
+  (get-sensor-id sensor-name))
+
+;; Get ID of sensor given by sensor-name
+;; define sensor if needed
+(define (sensor-id sensor-name)
+  (let ([id (get-sensor-id sensor-name)])
+    (cond ((void? id) (create-sensor-id sensor-id))
+          (else id))))
+
+(define (insert sensor-name value-float value-int value-string)
+  (let ([sensor-id (sensor-id sensor-name)]
+        [type (cond ((not (void? value-string)) "string")
+                    ((not (void? value-float)) "float")
+                    ((not (void? value-int)) "int"))])
+    (db:query-exec (string-append "INSERT INTO value(timestamp, sensor_id, type, value_float, value_int, value_string) "
+                                  "VALUES (now(), $1, $2, $3, $4, $5)")
+                   sensor-id type value-float value-int value-string)))
+