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 120
