SQLite

    p->aSortOrder = (u8*)pExtra;
    p->nColumn = nCol;
    p->nKeyCol = nCol - 1;
    *ppExtra = ((char*)p) + nByte;
  }
  return p;
}

/*
** Backwards Compatibility Hack:
** 
** Historical versions of SQLite accepted strings as column names in
** indexes and PRIMARY KEY constraints and in UNIQUE constraints.  Example:
**
**     CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)
**     CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);
**
** This is goofy.  But to preserve backwards compatibility we continue to
** accept it.  This routine does the necessary conversion.  It converts
** the expression given in its argument from a TK_STRING into a TK_ID
** if the expression is just a TK_STRING with an optional COLLATE clause.
** If the epxression is anything other than TK_STRING, the expression is
** unchanged.
*/
static void sqlite3StringToId(Expr *p){
  if( p->op==TK_STRING ){
    p->op = TK_ID;
  }else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){
    p->pLeft->op = TK_ID;
  }
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed.  pParse->pNewTable is a table that is

  */
  for(i=0, pListItem=pList->a; i<pList->nExpr; i++, pListItem++){
    const char *zColName;
    Expr *pCExpr;
    int requestedSortOrder;
    char *zColl;                   /* Collation sequence name */

    sqlite3StringToId(pListItem->pExpr);
    pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
    if( pCExpr->op!=TK_ID ){
      sqlite3ErrorMsg(pParse, "indexes on expressions not yet supported");
      continue;
    }
    zColName = pCExpr->u.zToken;
    for(j=0, pTabCol=pTab->aCol; j<pTab->nCol; j++, pTabCol++){

# 2005-01-11
#
# 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 CREATE INDEX statement.
#


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

# Create a table with a large number of columns
#
do_test index2-1.1 {

# 2005-02-14
#
# 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 CREATE INDEX statement.
#



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

# Ticket #1115.  Make sure that when a UNIQUE index is created on a
# non-unique column (or columns) that it fails and that it leaves no

    CREATE UNIQUE INDEX i1 ON t1(a);
  }
} {1 {UNIQUE constraint failed: t1.a}}
do_test index3-1.3 {
  catchsql COMMIT;
} {0 {}}
integrity_check index3-1.4

# Backwards compatibility test:
#
# Verify that CREATE INDEX statements that use strings instead of 
# identifiers for the the column names continue to work correctly.
# This is undocumented behavior retained for backwards compatiblity.
#
do_execsql_test index3-2.1 {
  DROP TABLE t1;
  CREATE TABLE t1(a, b, c, d, e, 
                  PRIMARY KEY('a'), UNIQUE('b' COLLATE nocase DESC));
  CREATE INDEX t1c ON t1('c');
  CREATE INDEX t1d ON t1('d' COLLATE binary ASC);
  WITH RECURSIVE c(x) AS (VALUES(1) UNION SELECT x+1 FROM c WHERE x<30)
    INSERT INTO t1(a,b,c,d,e) 
      SELECT x, printf('ab%03xxy',x), x, x, x FROM c;
} {}
do_execsql_test index3-2.2 {
  SELECT a FROM t1 WHERE b='ab005xy' COLLATE nocase;
} {5}
do_execsql_test index3-2.2eqp {
  EXPLAIN QUERY PLAN
  SELECT a FROM t1 WHERE b='ab005xy' COLLATE nocase;
} {/USING INDEX/}


# This test corrupts the database file so it must be the last test
# in the series.
#
do_test index3-99.1 {
  execsql {
    PRAGMA writable_schema=on;
    UPDATE sqlite_master SET sql='nonsense' WHERE name='t1d'
  }
  db close
  catch { sqlite3 db test.db }
  catchsql { DROP INDEX t1c }
} {1 {malformed database schema (t1d)}}

finish_test

    set maxy [execsql {select max(y) from t1}]
    execsql "
      INSERT INTO t2 SELECT 101-w, x, $maxy+1-y, y FROM t1;
    "
  }

  execsql {
    CREATE INDEX i1w ON t1("w");  -- Verify quoted identifier names
    CREATE INDEX i1xy ON t1(`x`,'y' ASC); -- Old MySQL compatibility
    CREATE INDEX i2p ON t2(p);
    CREATE INDEX i2r ON t2(r);
    CREATE INDEX i2qs ON t2(q, s);
  }
} {}

# Do an SQL statement.  Append the search count to the end of the result.

#
do_test where4-3.1 {
  execsql {
    CREATE TABLE t2(a);
    INSERT INTO t2 VALUES(1);
    INSERT INTO t2 VALUES(2);
    INSERT INTO t2 VALUES(3);
    CREATE TABLE t3(x,y,UNIQUE("x",'y' ASC)); -- Goofy syntax allowed
    INSERT INTO t3 VALUES(1,11);
    INSERT INTO t3 VALUES(2,NULL);
 
    SELECT * FROM t2 LEFT JOIN t3 ON a=x WHERE +y IS NULL;
  }
} {2 2 {} 3 {} {}}
do_test where4-3.2 {

} {}

# Ticket #2273.  Problems with IN operators and NULLs.
#
ifcapable subquery {
do_test where4-5.1 {
  execsql {
    -- Allow the 'x' syntax for backwards compatibility
    CREATE TABLE t4(x,y,z,PRIMARY KEY('x' ASC, "y" ASC));
  }
  execsql {
    SELECT *
      FROM t2 LEFT JOIN t4 b1
              LEFT JOIN t4 b2 ON b2.x=b1.x AND b2.y IN (b1.y);
  }
} {1 {} {} {} {} {} {} 2 {} {} {} {} {} {} 3 {} {} {} {} {} {}}

do_execsql_test 8.2 { SELECT * FROM u9 WHERE a IS NULL  } {{} 1 {} 2}
do_execsql_test 8.2 { SELECT * FROM u9 WHERE a IS $null } {{} 1 {} 2}




finish_test