SQLite

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.193 2006/01/23 13:22:09 drh Exp $
*/

// All token codes are small integers with #defines that begin with "TK_"
%token_prefix TK_

// The type of the data attached to each token is Token.  This is also the
// default type for non-terminals.

exprlist(A) ::= expritem(X).            {A = sqlite3ExprListAppend(0,X,0);}
expritem(A) ::= expr(X).                {A = X;}
expritem(A) ::= .                       {A = 0;}

///////////////////////////// The CREATE INDEX command ///////////////////////
//
cmd ::= CREATE(S) uniqueflag(U) INDEX ifnotexists(NE) nm(X) dbnm(D)
        ON nm(Y) LP idxlist(Z) RP(E) onconf(R). {
  if( U!=OE_None ) U = R;
  if( U==OE_Default) U = OE_Abort;
  sqlite3CreateIndex(pParse, &X, &D, sqlite3SrcListAppend(0,&Y,0), Z, U,
                      &S, &E, SQLITE_SO_ASC, NE);
}

%type uniqueflag {int}
uniqueflag(A) ::= UNIQUE.  {A = OE_Abort;}
uniqueflag(A) ::= .        {A = OE_None;}

#
# Run this Tcl script to generate the lang-*.html files.
#
set rcsid {$Id: lang.tcl,v 1.106 2006/01/23 18:14:22 drh Exp $}
source common.tcl

if {[llength $argv]>0} {
  set outputdir [lindex $argv 0]
} else {
  set outputdir ""
}

Section {CREATE INDEX} createindex

Syntax {sql-statement} {
CREATE [UNIQUE] INDEX [IF NOT EXISTS] [<database-name> .] <index-name> 
ON <table-name> ( <column-name> [, <column-name>]* )
[ ON CONFLICT <conflict-algorithm> ]
} {column-name} {
<name> [ COLLATE <collation-name>] [ ASC | DESC ]
}

puts {
<p>The CREATE INDEX command consists of the keywords "CREATE INDEX" followed
by the name of the new index, the keyword "ON", the name of a previously

<p>There are no arbitrary limits on the number of indices that can be
attached to a single table, nor on the number of columns in an index.</p>

<p>If the UNIQUE keyword appears between CREATE and INDEX then duplicate
index entries are not allowed.  Any attempt to insert a duplicate entry
will result in an error.</p>

<p>The optional conflict-clause allows the specification of an alternative
default constraint conflict resolution algorithm for this index.
This only makes sense if the UNIQUE keyword is used since otherwise
there are not constraints on the index.  The default algorithm is
ABORT.  If a COPY, INSERT, or UPDATE statement specifies a particular
conflict resolution algorithm, that algorithm is used in place of
the default algorithm specified here.
See the section titled
<a href="#conflict">ON CONFLICT</a> for additional information.</p>

<p>The exact text
of each CREATE INDEX statement is stored in the <b>sqlite_master</b>
or <b>sqlite_temp_master</b> table, depending on whether the table
being indexed is temporary.  Every time the database is opened,
all CREATE INDEX statements
are read from the <b>sqlite_master</b> table and used to regenerate
SQLite's internal representation of the index layout.</p>

puts {
<p>The ON CONFLICT clause is not a separate SQL command.  It is a
non-standard clause that can appear in many other SQL commands.
It is given its own section in this document because it is not
part of standard SQL and therefore might not be familiar.</p>

<p>The syntax for the ON CONFLICT clause is as shown above for
the CREATE TABLE and CREATE INDEX commands.  For the COPY, INSERT, and
UPDATE commands, the keywords "ON CONFLICT" are replaced by "OR", to make
the syntax seem more natural.  But the meaning of the clause is the same


either way.</p>

<p>The ON CONFLICT clause specifies an algorithm used to resolve
constraint conflicts.  There are five choices: ROLLBACK, ABORT,
FAIL, IGNORE, and REPLACE. The default algorithm is ABORT.  This
is what they mean:</p>

value, then the ABORT algorithm is used.</p>

<p>When this conflict resolution strategy deletes rows in order to
satisfy a constraint, it does not invoke delete triggers on those
rows.  But that may change in a future release.</p>
</dl>

<p>The algorithm specified in the OR clause of a COPY, INSERT, or UPDATE
overrides any algorithm specified in a CREATE TABLE or CREATE INDEX.
If no algorithm is specified anywhere, the ABORT algorithm is used.</p>
}
# <p>For additional information, see 
# <a href="conflict.html">conflict.html</a>.</p>

Section REINDEX reindex

Syntax {sql-statement} {
  REINDEX <collation name>
}
Syntax {sql-statement} {