sqlite/test/delete.test

# 2001 September 15
#
# 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 the DELETE FROM statement.
#
# $Id: delete.test,v 1.26 2009/06/05 17:09:12 drh Exp $

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

# Try to delete from a non-existant table.
#
do_test delete-1.1 {
  set v [catch {execsql {DELETE FROM test1}} msg]
  lappend v $msg
} {1 {no such table: test1}}

# Try to delete from sqlite_master
#
do_test delete-2.1 {
  set v [catch {execsql {DELETE FROM sqlite_master}} msg]
  lappend v $msg
} {1 {table sqlite_master may not be modified}}

# Delete selected entries from a table with and without an index.
#
do_test delete-3.1.1 {
  execsql {CREATE TABLE table1(f1 int, f2 int)}
  execsql {INSERT INTO table1 VALUES(1,2)}
  execsql {INSERT INTO table1 VALUES(2,4)}
  execsql {INSERT INTO table1 VALUES(3,8)}
  execsql {INSERT INTO table1 VALUES(4,16)}
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 2 4 3 8 4 16}
do_test delete-3.1.2 {
  execsql {DELETE FROM table1 WHERE f1=3}
} {}
do_test delete-3.1.3 {
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 2 4 4 16}
do_test delete-3.1.4 {
  execsql {CREATE INDEX index1 ON table1(f1)}
  execsql {PRAGMA count_changes=on}
  ifcapable explain {
    execsql {EXPLAIN DELETE FROM table1 WHERE f1=3}
  }
  execsql {DELETE FROM 'table1' WHERE f1=3}
} {0}
do_test delete-3.1.5 {
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 2 4 4 16}
do_test delete-3.1.6.1 {
  execsql {DELETE FROM table1 WHERE f1=2}
} {1}
do_test delete-3.1.6.2 {
  db changes
} 1
do_test delete-3.1.7 {
  execsql {SELECT * FROM table1 ORDER BY f1}
} {1 2 4 16}
integrity_check delete-3.2

# Semantic errors in the WHERE clause
#
do_test delete-4.1 {
  execsql {CREATE TABLE table2(f1 int, f2 int)}
  set v [catch {execsql {DELETE FROM table2 WHERE f3=5}} msg]
  lappend v $msg
} {1 {no such column: f3}}

do_test delete-4.2 {
  set v [catch {execsql {DELETE FROM table2 WHERE xyzzy(f1+4)}} msg]
  lappend v $msg
} {1 {no such function: xyzzy}}
integrity_check delete-4.3

# Lots of deletes
#
do_test delete-5.1.1 {
  execsql {DELETE FROM table1}
} {2}
do_test delete-5.1.2 {
  execsql {SELECT count(*) FROM table1}
} {0}
do_test delete-5.2.1 {
  execsql {BEGIN TRANSACTION}
  for {set i 1} {$i<=200} {incr i} {
     execsql "INSERT INTO table1 VALUES($i,[expr {$i*$i}])"
  }
  execsql {COMMIT}
  execsql {SELECT count(*) FROM table1}
} {200}
do_test delete-5.2.2 {
  execsql {DELETE FROM table1}
} {200}
do_test delete-5.2.3 {
  execsql {BEGIN TRANSACTION}
  for {set i 1} {$i<=200} {incr i} {
     execsql "INSERT INTO table1 VALUES($i,[expr {$i*$i}])"
  }
  execsql {COMMIT}
  execsql {SELECT count(*) FROM table1}
} {200}
do_test delete-5.2.4 {
  execsql {PRAGMA count_changes=off}
  execsql {DELETE FROM table1}
} {}
do_test delete-5.2.5 {
  execsql {SELECT count(*) FROM table1}
} {0}
do_test delete-5.2.6 {
  execsql {BEGIN TRANSACTION}
  for {set i 1} {$i<=200} {incr i} {
     execsql "INSERT INTO table1 VALUES($i,[expr {$i*$i}])"
  }
  execsql {COMMIT}
  execsql {SELECT count(*) FROM table1}
} {200}
do_test delete-5.3 {
  for {set i 1} {$i<=200} {incr i 4} {
     execsql "DELETE FROM table1 WHERE f1==$i"
  }
  execsql {SELECT count(*) FROM table1}
} {150}
do_test delete-5.4.1 {
  execsql "DELETE FROM table1 WHERE f1>50"
  db changes
} [db one {SELECT count(*) FROM table1 WHERE f1>50}]
do_test delete-5.4.2 {
  execsql {SELECT count(*) FROM table1}
} {37}
do_test delete-5.5 {
  for {set i 1} {$i<=70} {incr i 3} {
     execsql "DELETE FROM table1 WHERE f1==$i"
  }
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {2 3 6 8 11 12 14 15 18 20 23 24 26 27 30 32 35 36 38 39 42 44 47 48 50}
do_test delete-5.6 {
  for {set i 1} {$i<40} {incr i} {
     execsql "DELETE FROM table1 WHERE f1==$i"
  }
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {42 44 47 48 50}
do_test delete-5.7 {
  execsql "DELETE FROM table1 WHERE f1!=48"
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {48}
integrity_check delete-5.8


# Delete large quantities of data.  We want to test the List overflow
# mechanism in the vdbe.
#
do_test delete-6.1 {
  execsql {BEGIN; DELETE FROM table1}
  for {set i 1} {$i<=3000} {incr i} {
    execsql "INSERT INTO table1 VALUES($i,[expr {$i*$i}])"
  }
  execsql {DELETE FROM table2}
  for {set i 1} {$i<=3000} {incr i} {
    execsql "INSERT INTO table2 VALUES($i,[expr {$i*$i}])"
  }
  execsql {COMMIT}
  execsql {SELECT count(*) FROM table1}
} {3000}
do_test delete-6.2 {
  execsql {SELECT count(*) FROM table2}
} {3000}
do_test delete-6.3 {
  execsql {SELECT f1 FROM table1 WHERE f1<10 ORDER BY f1}
} {1 2 3 4 5 6 7 8 9}
do_test delete-6.4 {
  execsql {SELECT f1 FROM table2 WHERE f1<10 ORDER BY f1}
} {1 2 3 4 5 6 7 8 9}
do_test delete-6.5.1 {
  execsql {DELETE FROM table1 WHERE f1>7}
  db changes
} {2993}
do_test delete-6.5.2 {
  execsql {SELECT f1 FROM table1 ORDER BY f1}
} {1 2 3 4 5 6 7}
do_test delete-6.6 {
  execsql {DELETE FROM table2 WHERE f1>7}
  execsql {SELECT f1 FROM table2 ORDER BY f1}
} {1 2 3 4 5 6 7}
do_test delete-6.7 {
  execsql {DELETE FROM table1}
  execsql {SELECT f1 FROM table1}
} {}
do_test delete-6.8 {
  execsql {INSERT INTO table1 VALUES(2,3)}
  execsql {SELECT f1 FROM table1}
} {2}
do_test delete-6.9 {
  execsql {DELETE FROM table2}
  execsql {SELECT f1 FROM table2}
} {}
do_test delete-6.10 {
  execsql {INSERT INTO table2 VALUES(2,3)}
  execsql {SELECT f1 FROM table2}
} {2}
integrity_check delete-6.11

do_test delete-7.1 {
  execsql {
    CREATE TABLE t3(a);
    INSERT INTO t3 VALUES(1);
    INSERT INTO t3 SELECT a+1 FROM t3;
    INSERT INTO t3 SELECT a+2 FROM t3;
    SELECT * FROM t3;
  }
} {1 2 3 4}
ifcapable {trigger} {
  do_test delete-7.2 {
    execsql {
      CREATE TABLE cnt(del);
      INSERT INTO cnt VALUES(0);
      CREATE TRIGGER r1 AFTER DELETE ON t3 FOR EACH ROW BEGIN
        UPDATE cnt SET del=del+1;
      END;
      DELETE FROM t3 WHERE a<2;
      SELECT * FROM t3;
    }
  } {2 3 4}
  do_test delete-7.3 {
    execsql {
      SELECT * FROM cnt;
    }
  } {1}
  do_test delete-7.4 {
    execsql {
      DELETE FROM t3;
      SELECT * FROM t3;
    }
  } {}
  do_test delete-7.5 {
    execsql {
      SELECT * FROM cnt;
    }
  } {4}
  do_test delete-7.6 {
    execsql {
      INSERT INTO t3 VALUES(1);
      INSERT INTO t3 SELECT a+1 FROM t3;
      INSERT INTO t3 SELECT a+2 FROM t3;
      CREATE TABLE t4 AS SELECT * FROM t3;
      PRAGMA count_changes=ON;
      DELETE FROM t3;
      DELETE FROM t4;
    }
  } {4 4}
} ;# endif trigger
ifcapable {!trigger} {
  execsql {DELETE FROM t3}
}
integrity_check delete-7.7

# Make sure error messages are consistent when attempting to delete
# from a read-only database.  Ticket #304.
#
do_test delete-8.0 {
  execsql {
    PRAGMA count_changes=OFF;
    INSERT INTO t3 VALUES(123);
    SELECT * FROM t3;
  }
} {123}
db close
catch {forcedelete test.db-journal}
catch {file attributes test.db -permissions 0444}
catch {file attributes test.db -readonly 1}
sqlite3 db test.db
set ::DB [sqlite3_connection_pointer db]
do_test delete-8.1 {
  catchsql {
    DELETE FROM t3;
  }
} {1 {attempt to write a readonly database}}
do_test delete-8.2 {
  execsql {SELECT * FROM t3} 
} {123}
do_test delete-8.3 {
  catchsql {
    DELETE FROM t3 WHERE 1;
  }
} {1 {attempt to write a readonly database}}
do_test delete-8.4 {
  execsql {SELECT * FROM t3} 
} {123}

# Update for v3: In v2 the DELETE statement would succeed because no
# database writes actually occur. Version 3 refuses to open a transaction
# on a read-only file, so the statement fails.
do_test delete-8.5 {
  catchsql {
    DELETE FROM t3 WHERE a<100;
  }
# v2 result: {0 {}}
} {1 {attempt to write a readonly database}}
do_test delete-8.6 {
  execsql {SELECT * FROM t3}
} {123}
integrity_check delete-8.7

# Need to do the following for tcl 8.5 on mac. On that configuration, the
# -readonly flag is taken so seriously that a subsequent [forcedelete]
# (required before the next test file can be executed) will fail.
#
catch {file attributes test.db -readonly 0}
db close
forcedelete test.db test.db-journal

# The following tests verify that SQLite correctly handles the case
# where an index B-Tree is being scanned, the rowid column being read
# from each index entry and another statement deletes some rows from
# the index B-Tree. At one point this (obscure) scenario was causing 
# SQLite to return spurious SQLITE_CORRUPT errors and arguably incorrect
# query results. 
#
do_test delete-9.1 {
  sqlite3 db test.db
  execsql {
    CREATE TABLE t5(a, b);
    CREATE TABLE t6(c, d);
    INSERT INTO t5 VALUES(1, 2);
    INSERT INTO t5 VALUES(3, 4);
    INSERT INTO t5 VALUES(5, 6);
    INSERT INTO t6 VALUES('a', 'b');
    INSERT INTO t6 VALUES('c', 'd');
    CREATE INDEX i5 ON t5(a);
    CREATE INDEX i6 ON t6(c);
  }
} {}
do_test delete-9.2 {
  set res [list]
  db eval { SELECT t5.rowid AS r, c, d FROM t5, t6 ORDER BY a } {
    if {$r==2} { db eval { DELETE FROM t5 } }
    lappend res $r $c $d
  }
  set res
} {1 a b 1 c d 2 a b {} c d}
do_test delete-9.3 {
  execsql {
    INSERT INTO t5 VALUES(1, 2);
    INSERT INTO t5 VALUES(3, 4);
    INSERT INTO t5 VALUES(5, 6);
  }
  set res [list]
  db eval { SELECT t5.rowid AS r, c, d FROM t5, t6 ORDER BY a } {
    if {$r==2} { db eval { DELETE FROM t5 WHERE rowid = 2 } }
    lappend res $r $c $d
  }
  set res
} {1 a b 1 c d 2 a b {} c d 3 a b 3 c d}
do_test delete-9.4 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 VALUES(1, 2);
    INSERT INTO t5 VALUES(3, 4);
    INSERT INTO t5 VALUES(5, 6);
  }
  set res [list]
  db eval { SELECT t5.rowid AS r, c, d FROM t5, t6 ORDER BY a } {
    if {$r==2} { db eval { DELETE FROM t5 WHERE rowid = 1 } }
    lappend res $r $c $d
  }
  set res
} {1 a b 1 c d 2 a b 2 c d 3 a b 3 c d}
do_test delete-9.5 {
  execsql {
    DELETE FROM t5;
    INSERT INTO t5 VALUES(1, 2);
    INSERT INTO t5 VALUES(3, 4);
    INSERT INTO t5 VALUES(5, 6);
  }
  set res [list]
  db eval { SELECT t5.rowid AS r, c, d FROM t5, t6 ORDER BY a } {
    if {$r==2} { db eval { DELETE FROM t5 WHERE rowid = 3 } }
    lappend res $r $c $d
  }
  set res
} {1 a b 1 c d 2 a b 2 c d}

do_execsql_test delete-10.0 {
  CREATE TABLE t1(a INT UNIQUE, b INT);
  INSERT INTO t1(a,b) VALUES('1','2');
  SELECT * FROM t1 WHERE a='1' AND b='2';
} {1 2}

do_execsql_test delete-10.1 {
  DELETE FROM t1 WHERE a='1' AND b='2';
}

do_execsql_test delete-10.2 {
  SELECT * FROM t1 WHERE a='1' AND b='2';
}

do_execsql_test delete-11.0 {
  CREATE TABLE t11(a INTEGER PRIMARY KEY, b INT);
  WITH RECURSIVE cnt(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM cnt WHERE x<20)
    INSERT INTO t11(a,b) SELECT x, (x*17)%100 FROM cnt;
  SELECT * FROM t11;
} {1 17 2 34 3 51 4 68 5 85 6 2 7 19 8 36 9 53 10 70 11 87 12 4 13 21 14 38 15 55 16 72 17 89 18 6 19 23 20 40}
do_execsql_test delete-11.1 {
  DELETE FROM t11 AS xyz
   WHERE EXISTS(SELECT 1 FROM t11 WHERE t11.a>xyz.a AND t11.b<=xyz.b);
  SELECT * FROM t11;
} {6 2 12 4 18 6 19 23 20 40}


# 2023-03-15
# https://sqlite.org/forum/forumpost/e61252062c9d286d
#
# When the WHERE clause of a DELETE statement contains a subquery
# which uses the table that is being deleted from and there is a
# short-circuit operator of some kind in the WHERE clause such that
# the subquery might not run right away, then the subquery might
# run after one or more rows have been deleted, which can change
# the result of the subquery, and result in the wrong answer.
#
# Similar problem for UPDATE tested by update-21.4
# https://sqlite.org/forum/forumpost/0007d1fdb1
#
reset_db
do_execsql_test delete-12.0 {
  CREATE TABLE t0(vkey INTEGER, pkey INTEGER,c1 INTEGER);
  INSERT INTO t0 VALUES(2,1,-20),(2,2,NULL),(2,3,0),(8,4,95);
  DELETE FROM t0 WHERE NOT (
    (t0.vkey <= t0.c1) AND
    (t0.vkey <> (SELECT vkey FROM t0 ORDER BY vkey LIMIT 1 OFFSET 2))
  );
  SELECT * FROM t0;
} {8 4 95}

finish_test