# 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