sqlite/test/orderby9.test

63 lines
1.8 KiB
Plaintext
Raw Normal View History

# 2015-08-26
#
# 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 seeks to verify that expressions (and especially functions)
# that are in both the ORDER BY clause and the result set are only
# evaluated once.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix orderby9
do_execsql_test setup {
-- create a table with many entries
CREATE TABLE t1(x);
WITH RECURSIVE
c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
INSERT INTO t1 SELECT x FROM c;
}
# Some versions of TCL are unable to [lsort -int] for
# 64-bit integers. So we write our own comparison
# routine.
proc bigintcompare {a b} {
set x [expr {$a-$b}]
if {$x<0} {return -1}
if {$x>0} {return +1}
return 0
}
do_test 1.0 {
set l1 {}
# If random() is only evaluated once and then reused for each row, then
# the output should appear in sorted order. If random() is evaluated
# separately for the result set and the ORDER BY clause, then the output
# order will be random.
db eval {SELECT random() AS y FROM t1 ORDER BY 1;} {lappend l1 $y}
expr {$l1==[lsort -command bigintcompare $l1]}
} {1}
do_test 1.1 {
set l1 {}
db eval {SELECT random() AS y FROM t1 ORDER BY random();} {lappend l1 $y}
expr {$l1==[lsort -command bigintcompare $l1]}
} {1}
do_test 1.2 {
set l1 {}
db eval {SELECT random() AS y FROM t1 ORDER BY +random();} {lappend l1 $y}
expr {$l1==[lsort -command bigintcompare $l1]}
} {0}
finish_test