diff -r d59bea55db9b -r c445c931472f examples/sql/sudoku_mysql.mod
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/sql/sudoku_mysql.mod	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,113 @@
+/* SUDOKU, Number Placement Puzzle */
+
+/* Written in GNU MathProg by Andrew Makhorin <mao@mai2.rcnet.ru> */
+
+/* This example shows how to use the table statement.
+   The sudoku to be solves is read from file sudoku_in.csv.
+   The solution is written to sudoku_out.csv.
+   The file format is CSV as defined in
+     RFC 4180 - Common Format and MIME Type for
+     Comma-Separated Values (CSV) Files */
+
+/* Sudoku, also known as Number Place, is a logic-based placement
+   puzzle. The aim of the canonical puzzle is to enter a numerical
+   digit from 1 through 9 in each cell of a 9x9 grid made up of 3x3
+   subgrids (called "regions"), starting with various digits given in
+   some cells (the "givens"). Each row, column, and region must contain
+   only one instance of each numeral.
+
+   Example:
+
+   +-------+-------+-------+
+   | 5 3 . | . 7 . | . . . |
+   | 6 . . | 1 9 5 | . . . |
+   | . 9 8 | . . . | . 6 . |
+   +-------+-------+-------+
+   | 8 . . | . 6 . | . . 3 |
+   | 4 . . | 8 . 3 | . . 1 |
+   | 7 . . | . 2 . | . . 6 |
+   +-------+-------+-------+
+   | . 6 . | . . . | 2 8 . |
+   | . . . | 4 1 9 | . . 5 |
+   | . . . | . 8 . | . 7 9 |
+   +-------+-------+-------+
+
+   (From Wikipedia, the free encyclopedia.) */
+set fields dimen 2;
+
+param id;
+
+param givens{1..9, 1..9}, integer, >= 0, <= 9, default 0;
+/* the "givens" */
+
+/*
+table ti IN 'MySQL' 'Database=glpk;UID=glpk;PWD=gnu'
+  'sudoku' :
+  fields <- [COL, LIN], givens ~ VAL;
+*/
+table ti IN 'MySQL' 'Database=glpk;UID=glpk;PWD=gnu'
+  'SELECT * FROM sudoku WHERE ID = ' & id :
+  fields <- [COL, LIN], givens ~ VAL;
+
+var x{i in 1..9, j in 1..9, k in 1..9}, binary;
+/* x[i,j,k] = 1 means cell [i,j] is assigned number k */
+
+s.t. fa{i in 1..9, j in 1..9, k in 1..9: givens[i,j] != 0}:
+     x[i,j,k] = (if givens[i,j] = k then 1 else 0);
+/* assign pre-defined numbers using the "givens" */
+
+s.t. fb{i in 1..9, j in 1..9}: sum{k in 1..9} x[i,j,k] = 1;
+/* each cell must be assigned exactly one number */
+
+s.t. fc{i in 1..9, k in 1..9}: sum{j in 1..9} x[i,j,k] = 1;
+/* cells in the same row must be assigned distinct numbers */
+
+s.t. fd{j in 1..9, k in 1..9}: sum{i in 1..9} x[i,j,k] = 1;
+/* cells in the same column must be assigned distinct numbers */
+
+s.t. fe{I in 1..9 by 3, J in 1..9 by 3, k in 1..9}:
+     sum{i in I..I+2, j in J..J+2} x[i,j,k] = 1;
+/* cells in the same region must be assigned distinct numbers */
+
+/* there is no need for an objective function here */
+
+solve;
+
+table ta{(i,j) in fields} OUT
+  'MySQL' 'Database=glpk;UID=glpk;PWD=gnu'
+  'DELETE FROM sudoku_solution'
+  'WHERE ID = ' & id & ';'
+  'INSERT INTO sudoku_solution'
+  '(ID, COL, LIN, VAL)'
+  'VALUES(?, ?, ?, ?);' :
+  id ~ ID, i ~ COL, j ~ LIN, (sum{k in 1..9} x[i,j,k] * k) ~ VAL;
+
+printf "\nSudoku to be solved\n";
+for {i in 1..9}
+{  for {0..0: i = 1 or i = 4 or i = 7}
+     printf " +-------+-------+-------+\n";
+   for {j in 1..9}
+   {  for {0..0: j = 1 or j = 4 or j = 7} printf(" |");
+      printf " %d", givens[i,j];
+      for {0..0: j = 9} printf(" |\n");
+   }
+   for {0..0: i = 9}
+   printf " +-------+-------+-------+\n";
+   }
+printf "\nSolution\n";
+for {i in 1..9}
+{  for {0..0: i = 1 or i = 4 or i = 7}
+      printf " +-------+-------+-------+\n";
+   for {j in 1..9}
+   {  for {0..0: j = 1 or j = 4 or j = 7} printf(" |");
+      printf " %d", sum{k in 1..9} x[i,j,k] * k;
+      for {0..0: j = 9} printf(" |\n");
+   }
+   for {0..0: i = 9}
+      printf " +-------+-------+-------+\n";
+}
+
+data;
+
+param id := 1;
+end;