upload luasqlite3

examples/aggregate.lua

@@ -0,0 +1,35 @@
+
+local sqlite3 = require("lsqlite3")
+
+local db = sqlite3.open_memory()
+
+assert( db:exec "CREATE TABLE test (col1, col2)" )
+assert( db:exec "INSERT INTO test VALUES (1, 2)" )
+assert( db:exec "INSERT INTO test VALUES (2, 4)" )
+assert( db:exec "INSERT INTO test VALUES (3, 6)" )
+assert( db:exec "INSERT INTO test VALUES (4, 8)" )
+assert( db:exec "INSERT INTO test VALUES (5, 10)" )
+
+do
+
+  local square_error_sum = 0
+
+  local function step(ctx, a, b)
+    local error        = a - b
+    local square_error = error * error
+    square_error_sum   = square_error_sum + square_error
+  end
+
+  local function final(ctx)
+    ctx:result_number( square_error_sum / ctx:aggregate_count() )
+  end
+
+  assert( db:create_aggregate("my_stats", 2, step, final) )
+
+end
+
+--for a,b in db:urows("SELECT col1, col2 FROM test")
+--do print("a b: ", a, b) end
+
+for my_stats in db:urows("SELECT my_stats(col1, col2) FROM test")
+do print("my_stats:", my_stats) end