persistentstorage/sqlite3api/TEST/TclScript/delete2.test
changeset 0 08ec8eefde2f
equal deleted inserted replaced
-1:000000000000 0:08ec8eefde2f
       
     1 # 2003 September 6
       
     2 #
       
     3 # The author disclaims copyright to this source code.  In place of
       
     4 # a legal notice, here is a blessing:
       
     5 #
       
     6 #    May you do good and not evil.
       
     7 #    May you find forgiveness for yourself and forgive others.
       
     8 #    May you share freely, never taking more than you give.
       
     9 #
       
    10 #***********************************************************************
       
    11 # This file implements regression tests for SQLite library.  The
       
    12 # focus of this script is a test to replicate the bug reported by
       
    13 # ticket #842.
       
    14 #
       
    15 # Ticket #842 was a database corruption problem caused by a DELETE that
       
    16 # removed an index entry by not the main table entry.  To recreate the
       
    17 # problem do this:
       
    18 #
       
    19 #   (1) Create a table with an index.  Insert some data into that table.
       
    20 #   (2) Start a query on the table but do not complete the query.
       
    21 #   (3) Try to delete a single entry from the table.
       
    22 #
       
    23 # Step 3 will fail because there is still a read cursor on the table.
       
    24 # But the database is corrupted by the DELETE.  It turns out that the
       
    25 # index entry was deleted first, before the table entry.  And the index
       
    26 # delete worked.  Thus an entry was deleted from the index but not from
       
    27 # the table.
       
    28 #
       
    29 # The solution to the problem was to detect that the table is locked
       
    30 # before the index entry is deleted.
       
    31 #
       
    32 # $Id: delete2.test,v 1.8 2008/07/08 15:59:52 danielk1977 Exp $
       
    33 #
       
    34 
       
    35 set testdir [file dirname $argv0]
       
    36 source $testdir/tester.tcl
       
    37 
       
    38 # Create a table that has an index.
       
    39 #
       
    40 do_test delete2-1.1 {
       
    41   set DB [sqlite3_connection_pointer db]
       
    42   execsql {
       
    43     CREATE TABLE q(s string, id string, constraint pk_q primary key(id));
       
    44     BEGIN;
       
    45     INSERT INTO q(s,id) VALUES('hello','id.1');
       
    46     INSERT INTO q(s,id) VALUES('goodbye','id.2');
       
    47     INSERT INTO q(s,id) VALUES('again','id.3');
       
    48     END;
       
    49     SELECT * FROM q;
       
    50   }
       
    51 } {hello id.1 goodbye id.2 again id.3}
       
    52 do_test delete2-1.2 {
       
    53   execsql {
       
    54     SELECT * FROM q WHERE id='id.1';
       
    55   }
       
    56 } {hello id.1}
       
    57 integrity_check delete2-1.3
       
    58 
       
    59 # Start a query on the table.  The query should not use the index.
       
    60 # Do not complete the query, thus leaving the table locked.
       
    61 #
       
    62 do_test delete2-1.4 {
       
    63   set STMT [sqlite3_prepare $DB {SELECT * FROM q} -1 TAIL]
       
    64   sqlite3_step $STMT
       
    65 } SQLITE_ROW
       
    66 integrity_check delete2-1.5
       
    67 
       
    68 # Try to delete a row from the table while a read is in process.
       
    69 # As of 2006-08-16, this is allowed.  (It used to fail with SQLITE_LOCKED.)
       
    70 #
       
    71 do_test delete2-1.6 {
       
    72   catchsql {
       
    73     DELETE FROM q WHERE rowid=1
       
    74   }
       
    75 } {0 {}}
       
    76 integrity_check delete2-1.7
       
    77 do_test delete2-1.8 {
       
    78   execsql {
       
    79     SELECT * FROM q;
       
    80   }
       
    81 } {goodbye id.2 again id.3}
       
    82 
       
    83 # Finalize the query, thus clearing the lock on the table.  Then
       
    84 # retry the delete.  The delete should work this time.
       
    85 #
       
    86 do_test delete2-1.9 {
       
    87   sqlite3_finalize $STMT
       
    88   catchsql {
       
    89     DELETE FROM q WHERE rowid=1
       
    90   }
       
    91 } {0 {}}
       
    92 integrity_check delete2-1.10
       
    93 do_test delete2-1.11 {
       
    94   execsql {
       
    95     SELECT * FROM q;
       
    96   }
       
    97 } {goodbye id.2 again id.3}
       
    98 
       
    99 do_test delete2-2.1 {
       
   100   execsql {
       
   101     CREATE TABLE t1(a, b);
       
   102     CREATE TABLE t2(c, d);
       
   103     INSERT INTO t1 VALUES(1, 2);
       
   104     INSERT INTO t2 VALUES(3, 4);
       
   105     INSERT INTO t2 VALUES(5, 6);
       
   106   }
       
   107 } {}
       
   108 do_test delete2-2.2 {
       
   109   set res [list]
       
   110   db eval {
       
   111     SELECT CASE WHEN c = 5 THEN b ELSE NULL END AS b, c, d FROM t1, t2
       
   112   } {
       
   113     db eval {DELETE FROM t1}
       
   114     lappend res $b $c $d
       
   115   }
       
   116   set res
       
   117 } {{} 3 4 {} 5 6}
       
   118 
       
   119 finish_test