First Commit

ext/libpqxx-7.7.3/test/test84.cxx

@@ -0,0 +1,109 @@
+#include <algorithm>
+#include <cstdio>
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <pqxx/cursor>
+#include <pqxx/transaction>
+
+#include "test_helpers.hxx"
+
+
+// "Adopted SQL Cursor" test program for libpqxx.  Create SQL cursor, wrap it
+// in a cursor stream, then use it to fetch data and check for consistent
+// results. Compare results against an icursor_iterator so that is tested as
+// well.
+namespace
+{
+void test_084()
+{
+  pqxx::connection conn;
+  pqxx::transaction<pqxx::serializable> tx{conn};
+
+  std::string const Table{"pg_tables"}, Key{"tablename"};
+
+  // Count rows.
+  pqxx::result R(tx.exec("SELECT count(*) FROM " + Table));
+
+  PQXX_CHECK(
+    R.at(0).at(0).as<long>() > 20,
+    "Not enough rows in " + Table + ", cannot test.");
+
+  // Create an SQL cursor and, for good measure, muddle up its state a bit.
+  std::string const CurName{"MYCUR"},
+    Query{"SELECT * FROM " + Table + " ORDER BY " + Key};
+  constexpr int InitialSkip{2}, GetRows{3};
+
+  tx.exec0("DECLARE " + tx.quote_name(CurName) + " CURSOR FOR " + Query);
+  tx.exec0(
+    "MOVE " + pqxx::to_string(InitialSkip * GetRows) +
+    " "
+    "IN " +
+    tx.quote_name(CurName));
+
+  // Wrap cursor in cursor stream.  Apply some trickery to get its name inside
+  // a result field for this purpose.  This isn't easy because it's not
+  // supposed to be easy; normally we'd only construct streams around existing
+  // SQL cursors if they were being returned by functions.
+  pqxx::icursorstream C{
+    tx, tx.exec("SELECT '" + tx.esc(CurName) + "'")[0][0], GetRows};
+
+  // Create parallel cursor to check results
+  pqxx::icursorstream C2{tx, Query, "CHECKCUR", GetRows};
+  pqxx::icursor_iterator i2{C2};
+
+  // Remember, our adopted cursor is at position (InitialSkip*GetRows)
+  pqxx::icursor_iterator i3(i2);
+
+  PQXX_CHECK(
+    (i3 == i2) and not(i3 != i2),
+    "Equality on copy-constructed icursor_iterator is broken.");
+  PQXX_CHECK(
+    not(i3 > i2) and not(i3 < i2) and (i3 <= i2) and (i3 >= i2),
+    "Comparison on identical icursor_iterators is broken.");
+
+  i3 += InitialSkip;
+
+  PQXX_CHECK(not(i3 <= i2), "icursor_iterator operator<=() is broken.");
+
+  pqxx::icursor_iterator iend, i4;
+  PQXX_CHECK(i3 != iend, "Early end to icursor_iterator iteration.");
+  i4 = iend;
+  PQXX_CHECK(i4 == iend, "Assigning empty icursor_iterator fails.");
+
+  // Now start testing our new Cursor.
+  C >> R;
+  i2 = i3;
+  pqxx::result R2(*i2++);
+
+  PQXX_CHECK_EQUAL(
+    std::size(R), static_cast<pqxx::result::size_type>(GetRows),
+    "Got unexpected number of rows.");
+
+  PQXX_CHECK_EQUAL(R, R2, "Unexpected result at [1]");
+
+  C.get(R);
+  R2 = *i2;
+  PQXX_CHECK_EQUAL(R, R2, "Unexpected result at [2]");
+  i2 += 1;
+
+  C.ignore(GetRows);
+  C.get(R);
+  R2 = *++i2;
+
+  PQXX_CHECK_EQUAL(R, R2, "Unexpected result at [3]");
+
+  ++i2;
+  R2 = *i2++;
+  for (int i{1}; C.get(R) and i2 != iend; R2 = *i2++, ++i)
+    PQXX_CHECK_EQUAL(
+      R, R2, "Unexpected result in iteration at " + pqxx::to_string(i));
+
+  PQXX_CHECK(i2 == iend, "Adopted cursor terminated early.");
+  PQXX_CHECK(not(C >> R), "icursor_iterator terminated early.");
+}
+} // namespace
+
+
+PQXX_REGISTER_TEST(test_084);