upload luasqlite3

examples/order.lua

@@ -0,0 +1,122 @@
+
+local sqlite3 = require("lsqlite3")
+
+local db = assert( sqlite3:open_memory() )
+
+assert( db:exec[[
+
+  CREATE TABLE customer (
+    id		INTEGER PRIMARY KEY, 
+    name	VARCHAR(40)
+  );
+
+  CREATE TABLE invoice (
+    id		INTEGER PRIMARY KEY,
+    customer	INTEGER NOT NULL,
+    title	VARCHAR(80) NOT NULL,
+    article1	VARCHAR(40) NOT NULL,
+    price1	REAL NOT NULL,
+    article2	VARCHAR(40),
+    price2	REAL
+  );
+
+  CREATE TABLE invoice_overflow (
+    id		INTEGER PRIMARY KEY,
+    invoice	INTEGER NOT NULL,
+    article	VARCHAR(40) NOT NULL,
+    price	REAL NOT NULL
+  );
+
+  INSERT INTO customer VALUES(
+    1, "Michael" );
+
+  INSERT INTO invoice VALUES(
+    1, 1, "Computer parts", "harddisc", 89.90, "floppy", 9.99 );
+
+  INSERT INTO customer VALUES(
+    2, "John" );
+
+  INSERT INTO invoice VALUES(
+    2, 2, "Somme food", "apples", 2.79, "pears", 5.99 );
+
+  INSERT INTO invoice_overflow VALUES(
+    NULL, 2, "grapes", 6.34 );
+
+  INSERT INTO invoice_overflow VALUES(
+    NULL, 2, "strawberries", 4.12 );
+
+  INSERT INTO invoice_overflow VALUES(
+    NULL, 2, "tomatoes", 6.17 );
+
+  INSERT INTO invoice VALUES(
+    3, 2, "A new car", "Cybercar XL-1000", 65000.00, NULL, NULL );
+
+]] )
+
+
+local function customer_name(id)
+  local stmt = db:prepare("SELECT name FROM customer WHERE id = ?")
+  stmt:bind_values(id)
+  stmt:step()
+  local r = stmt:get_uvalues()
+  stmt:finalize()
+  return r
+end
+
+
+local function all_invoices()
+  return db:nrows("SELECT id, customer, title FROM invoice")
+end
+
+
+local function all_articles(invoice)
+
+  local function iterator()
+    local stmt, row
+
+    -- Get the articles that are contained in the invoice table itself.
+    stmt = db:prepare("SELECT article1, price1, article2, price2 FROM invoice WHERE id = ?")
+    stmt:bind_values(invoice)
+    stmt:step()
+    row = stmt:get_named_values()
+
+    -- Every Invoice has at least one article.
+    coroutine.yield(row.article1, row.price1)
+
+    -- Maybe the Invoice has a second article?
+    if row.article2 then
+
+      -- Yes, there is a second article, so return it.
+      coroutine.yield(row.article2, row.price2)
+
+      -- When there was an second article, maybe there are even
+      -- more articles in the overflow table? We will see...
+
+      stmt = db:prepare("SELECT article, price FROM invoice_overflow WHERE invoice = ? ORDER BY id")
+      stmt:bind_values(invoice)
+      
+      for row in stmt:nrows() do
+        coroutine.yield(row.article, row.price)
+      end
+    end
+  end
+
+  return coroutine.wrap(iterator)
+end
+
+
+for invoice in all_invoices() do
+  local id    = invoice.id
+  local name  = customer_name(invoice.customer)
+  local title = invoice.title
+
+  print()
+  print("Invoice #"..id..", "..name..": '"..title.."'")
+  print("----------------------------------------")
+
+  for article, price in all_articles(id) do
+    print( string.format("%20s  %8.2f", article, price) )
+  end
+
+  print()
+end