zeroblob.test

sqlite-3.4.1,嵌入式数据库.是一个功能强大的开源数据库,给学习和研发以及小型公司的发展带来了全所未有的好处.

# 2007 May 02
#
# 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.  The
# focus of this file is testing of the zero-filled blob functionality
# including the sqlite3_bind_zeroblob(), sqlite3_result_zeroblob(),
# and the built-in zeroblob() SQL function.
#
# $Id: zeroblob.test,v 1.6 2007/06/07 19:08:34 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !incrblob {
  finish_test
  return
}

# When zeroblob() is used for the last field of a column, then the
# content of the zeroblob is never instantiated on the VDBE stack.
# But it does get inserted into the database correctly.
#
do_test zeroblob-1.1 {
  execsql {
    CREATE TABLE t1(a,b,c,d);
  }
  set ::sqlite3_max_blobsize 0
  execsql {
    INSERT INTO t1 VALUES(2,3,4,zeroblob(10000));
  }
  set ::sqlite3_max_blobsize
} {10}
do_test zeroblob-1.2 {
  execsql {
    SELECT length(d) FROM t1
  }
} {10000}

# If a non-NULL column follows the zeroblob, then the content of
# the zeroblob must be instantiated.
#
do_test zeroblob-1.3 {
  set ::sqlite3_max_blobsize 0
  execsql {
    INSERT INTO t1 VALUES(3,4,zeroblob(10000),5);
  }
  set ::sqlite3_max_blobsize
} {10010}
do_test zeroblob-1.4 {
  execsql {
    SELECT length(c), length(d) FROM t1
  }
} {1 10000 10000 1}

# Multiple zeroblobs can appear at the end of record.  No instantiation
# of the blob content occurs on the stack.
#
do_test zeroblob-1.5 {
  set ::sqlite3_max_blobsize 0
  execsql {
    INSERT INTO t1 VALUES(4,5,zeroblob(10000),zeroblob(10000));
  }
  set ::sqlite3_max_blobsize
} {11}
do_test zeroblob-1.6 {
  execsql {
    SELECT length(c), length(d) FROM t1
  }
} {1 10000 10000 1 10000 10000}

# NULLs can follow the zeroblob() or be intermixed with zeroblobs and
# no instantiation of the zeroblobs occurs on the stack.
#
do_test zeroblob-1.7 {
  set ::sqlite3_max_blobsize 0
  execsql {
    INSERT INTO t1 VALUES(5,zeroblob(10000),NULL,zeroblob(10000));
  }
  set ::sqlite3_max_blobsize
} {10}
do_test zeroblob-1.8 {
  execsql {
    SELECT length(b), length(d) FROM t1 WHERE a=5
  }
} {10000 10000}

# Comparisons against zeroblobs work.
#
do_test zeroblob-2.1 {
  execsql {
    SELECT a FROM t1 WHERE b=zeroblob(10000)
  }
} {5}

# Comparisons against zeroblobs work even when indexed.
#
do_test zeroblob-2.2 {
  execsql {
    CREATE INDEX i1_1 ON t1(b);
    SELECT a FROM t1 WHERE b=zeroblob(10000);
  }
} {5}

# DISTINCT works for zeroblobs
#
do_test zeroblob-3.1 {
  execsql {
    SELECT count(DISTINCT a) FROM (
      SELECT x'00000000000000000000' AS a
      UNION ALL
      SELECT zeroblob(10) AS a
    )
  }
} {1}

# Concatentation works with zeroblob
#
do_test zeroblob-4.1 {
  execsql {
    SELECT hex(zeroblob(2) || x'61')
  }
} {000061}

# Check various CAST(...) operations on zeroblob.
#
do_test zeroblob-5.1 {
  execsql {
    SELECT CAST (zeroblob(100) AS REAL);
  }
} {0.0}
do_test zeroblob-5.2 {
  execsql {
    SELECT CAST (zeroblob(100) AS INTEGER);
  }
} {0}
do_test zeroblob-5.3 {
  execsql {
    SELECT CAST (zeroblob(100) AS TEXT);
  }
} {{}}
do_test zeroblob-5.4 {
  execsql {
    SELECT CAST(zeroblob(100) AS BLOB);
  }
} [execsql {SELECT zeroblob(100)}]
  

# Check for malicious use of zeroblob.  Make sure nothing crashes.
#
do_test zeroblob-6.1.1 { 
  execsql {select zeroblob(-1)} 
} {{}} 
do_test zeroblob-6.1.2 { 
  execsql {select zeroblob(-10)} 
} {{}} 
do_test zeroblob-6.1.3 { 
  execsql {select zeroblob(-100)} 
} {{}} 
do_test zeroblob-6.2 { 
  execsql {select length(zeroblob(-1))} 
} {0} 
do_test zeroblob-6.3 { 
  execsql {select zeroblob(-1)|1} 
} {1} 
do_test zeroblob-6.4 { 
  catchsql {select length(zeroblob(2147483648))} 
} {1 {string or blob too big}} 
do_test zeroblob-6.5 { 
  catchsql {select zeroblob(2147483648)} 
} {1 {string or blob too big}} 

finish_test