# 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
