# 2008 July 11

 #

 # The author disclaims copyright to this source code.  In place of

 # a legal notice, here is a blessing:

 #

 #    May you do good and not evil.

 #    May you find forgiveness for yourself and forgive others.

 #    May you share freely, never taking more than you give.

 #

 #***********************************************************************

 # This file implements regression tests for SQLite library.

 #

 # This file experiments with recursion using the "test_eval()" SQL function

 # in order to make sure that SQLite is reentrant.

 #

 # $Id: eval.test,v 1.1 2008/07/11 21:02:54 drh Exp $

 set testdir [file dirname $argv0]

 source $testdir/tester.tcl

 # Create a table to work with.

 #

 do_test eval-1.1 {

   execsql {

     CREATE TABLE t1(x INTEGER PRIMARY KEY); 

     INSERT INTO t1 VALUES(1);

     INSERT INTO t1 VALUES(2);

     INSERT INTO t1 SELECT x+2 FROM t1;

     INSERT INTO t1 SELECT x+4 FROM t1;

     INSERT INTO t1 SELECT x+8 FROM t1;

     INSERT INTO t1 SELECT x+16 FROM t1;

     INSERT INTO t1 SELECT x+32 FROM t1;

     INSERT INTO t1 SELECT x+64 FROM t1;

     INSERT INTO t1 SELECT x+128 FROM t1;

     INSERT INTO t1 SELECT x+256 FROM t1;

     SELECT count(*), max(x) FROM t1;

   }

 } {512 512}

 do_test eval-1.2 {

   execsql {

     SELECT x, test_eval('SELECT max(x) FROM t1 WHERE x<' || x) FROM t1 LIMIT 5

   }

 } {1 {} 2 1 3 2 4 3 5 4}

 # Delete a row out from under a read cursor in the middle of

 # collecting the arguments for a single row in a result set.

 # Verify that subsequent rows come out as NULL.

 #

 do_test eval-2.1 {

   execsql {

     CREATE TABLE t2(x,y);

     INSERT INTO t2 SELECT x, x+1 FROM t1 WHERE x<5;

     SELECT x, test_eval('DELETE FROM t2 WHERE x='||x), y FROM t2;

   }

 } {1 {} {} 2 {} {} 3 {} {} 4 {} {}}

 do_test eval-2.2 {

   execsql {

     SELECT * FROM t2

   }

 } {}

 # Modify a row while it is being read.

 #

 do_test eval-3.1 {

   execsql {

     INSERT INTO t2 SELECT x, x+1 FROM t1 WHERE x<5;

     SELECT x, test_eval('UPDATE t2 SET y=y+100 WHERE x='||x), y FROM t2;

   }

 } {1 {} 102 2 {} 103 3 {} 104 4 {} 105}

 finish_test