From c3853f6dd796615f332fefcaaaf563794d867ee4 Mon Sep 17 00:00:00 2001
From: Richard Knight <q@1bpm.net>
Date: Tue, 17 Mar 2020 18:47:36 +0000
Subject: initial

---
 examples/3-postgresql-basic.csd | 100 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 examples/3-postgresql-basic.csd

(limited to 'examples/3-postgresql-basic.csd')

diff --git a/examples/3-postgresql-basic.csd b/examples/3-postgresql-basic.csd
new file mode 100644
index 0000000..053ee07
--- /dev/null
+++ b/examples/3-postgresql-basic.csd
@@ -0,0 +1,100 @@
+<CsoundSynthesizer>
+<CsOptions>
+-odac
+</CsOptions>
+<CsInstruments>
+/*
+    EXAMPLE 3
+
+    Run some queries on a PostgreSQL database using just inbuilt functions and system tables
+    
+
+*/
+
+sr = 44100
+kr = 4410
+nchnls = 2
+0dbfs = 1
+seed 0
+
+
+; connect: type, hostname or IP, database name, username, password
+gidb dbconnect "postgresql", "localhost", "databasename", "username", "password"
+
+
+; print a random float from the database
+instr execscalar
+    ires dbscalar gidb, "SELECT RANDOM()"
+    print ires
+endin
+
+
+; print the current_timestamp from the database
+instr execscalarstr
+    Sres dbscalar gidb, "SELECT current_timestamp || '\n'"
+    prints Sres
+endin
+
+
+; print some float columns from the database activity statistics table
+instr execarray
+    ires[][] dbarray gidb, "SELECT datid, pid, usesysid FROM pg_stat_activity"
+    printarray ires
+endin
+
+
+; print some string columns from the database activity table
+instr execarraystr
+    Sres[][] dbarray gidb, "SELECT datname, usename, state, query_start FROM pg_stat_activity"
+    irow = 0
+
+    ; loop through as printarray does not support multidimensional string arrays
+    while (irow < lenarray(Sres)) do
+        icol = 0
+        while (icol < 3) do
+            Sitem sprintf "%d, %d : %s\n", irow, icol, Sres[irow][icol]
+            prints Sitem
+            icol += 1
+        od
+        irow += 1
+    od
+    
+endin
+
+
+; print the current_timestamp from the database server twice per second, and print when the query has been executed
+instr execscalar_k
+    ktrigger metro 2
+    kdone, Sres dbscalar_k gidb, "SELECT 'now = ' || current_timestamp || '\n'", ktrigger
+    if (kdone == 1) then
+        printks "%s", 0, Sres
+    endif
+endin
+
+
+; print 2x2 random floats from the database every second
+instr execarray_k
+    ktrigger metro 1
+    kdone, kres[][] dbarray_k gidb, "SELECT RANDOM(), RANDOM() UNION SELECT RANDOM(), RANDOM()", ktrigger
+    if (kdone == 1) then
+        printk2 kres[0][0]
+        printk2 kres[0][1]
+        printk2 kres[1][0]
+        printk2 kres[1][1]
+    endif
+
+endin
+
+
+</CsInstruments>
+<CsScore>
+
+i "execscalar" 0 1
+i "execscalarstr" 2 1
+i "execarray" 4 1
+i "execarraystr" 6 1
+i "execscalar_k" 7 5
+i "execarray_k" 12 5
+
+</CsScore>
+</CsoundSynthesizer>
\ No newline at end of file
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