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mariadb/sql/sql_lex.cc
kent@mysql.com 4cc58e7ff2 Merge bk-internal:/home/bk/mysql-5.0 
into  mysql.com:/data0/mysqldev/my/mysql-5.0
2006-06-02 21:41:57 +02:00

2171 lines
55 KiB
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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* A lexical scanner on a temporary buffer with a yacc interface */
#define MYSQL_LEX 1
#include "mysql_priv.h"
#include "item_create.h"
#include <m_ctype.h>
#include <hash.h>
#include "sp.h"
#include "sp_head.h"
/*
We are using pointer to this variable for distinguishing between assignment
to NEW row field (when parsing trigger definition) and structured variable.
*/
sys_var_long_ptr trg_new_row_fake_var(0, 0);
/* Macros to look like lex */
#define yyGet() *(lex->ptr++)
#define yyGetLast() lex->ptr[-1]
#define yyPeek() lex->ptr[0]
#define yyPeek2() lex->ptr[1]
#define yyUnget() lex->ptr--
#define yySkip() lex->ptr++
#define yyLength() ((uint) (lex->ptr - lex->tok_start)-1)
pthread_key(LEX*,THR_LEX);
/* Longest standard keyword name */
#define TOCK_NAME_LENGTH 24
/*
The following data is based on the latin1 character set, and is only
used when comparing keywords
*/
static uchar to_upper_lex[]=
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
96, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,123,124,125,126,127,
128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
208,209,210,211,212,213,214,247,216,217,218,219,220,221,222,255
};
inline int lex_casecmp(const char *s, const char *t, uint len)
{
while (len-- != 0 &&
to_upper_lex[(uchar) *s++] == to_upper_lex[(uchar) *t++]) ;
return (int) len+1;
}
#include "lex_hash.h"
void lex_init(void)
{
uint i;
DBUG_ENTER("lex_init");
for (i=0 ; i < array_elements(symbols) ; i++)
symbols[i].length=(uchar) strlen(symbols[i].name);
for (i=0 ; i < array_elements(sql_functions) ; i++)
sql_functions[i].length=(uchar) strlen(sql_functions[i].name);
VOID(pthread_key_create(&THR_LEX,NULL));
DBUG_VOID_RETURN;
}
void lex_free(void)
{ // Call this when daemon ends
DBUG_ENTER("lex_free");
DBUG_VOID_RETURN;
}
/*
This is called before every query that is to be parsed.
Because of this, it's critical to not do too much things here.
(We already do too much here)
*/
void lex_start(THD *thd, uchar *buf,uint length)
{
LEX *lex= thd->lex;
DBUG_ENTER("lex_start");
lex->thd= lex->unit.thd= thd;
lex->buf= lex->ptr= buf;
lex->end_of_query= buf+length;
lex->context_stack.empty();
lex->unit.init_query();
lex->unit.init_select();
/* 'parent_lex' is used in init_query() so it must be before it. */
lex->select_lex.parent_lex= lex;
lex->select_lex.init_query();
lex->value_list.empty();
lex->update_list.empty();
lex->param_list.empty();
lex->view_list.empty();
lex->prepared_stmt_params.empty();
lex->unit.next= lex->unit.master=
lex->unit.link_next= lex->unit.return_to= 0;
lex->unit.prev= lex->unit.link_prev= 0;
lex->unit.slave= lex->unit.global_parameters= lex->current_select=
lex->all_selects_list= &lex->select_lex;
lex->select_lex.master= &lex->unit;
lex->select_lex.prev= &lex->unit.slave;
lex->select_lex.link_next= lex->select_lex.slave= lex->select_lex.next= 0;
lex->select_lex.link_prev= (st_select_lex_node**)&(lex->all_selects_list);
lex->select_lex.options= 0;
lex->select_lex.init_order();
lex->select_lex.group_list.empty();
lex->describe= 0;
lex->subqueries= FALSE;
lex->view_prepare_mode= FALSE;
lex->stmt_prepare_mode= FALSE;
lex->derived_tables= 0;
lex->lock_option= TL_READ;
lex->found_semicolon= 0;
lex->safe_to_cache_query= 1;
lex->time_zone_tables_used= 0;
lex->leaf_tables_insert= 0;
lex->variables_used= 0;
lex->empty_field_list_on_rset= 0;
lex->select_lex.select_number= 1;
lex->next_state=MY_LEX_START;
lex->yylineno = 1;
lex->in_comment=0;
lex->length=0;
lex->select_lex.in_sum_expr=0;
lex->select_lex.expr_list.empty();
lex->select_lex.ftfunc_list_alloc.empty();
lex->select_lex.ftfunc_list= &lex->select_lex.ftfunc_list_alloc;
lex->select_lex.group_list.empty();
lex->select_lex.order_list.empty();
lex->current_select= &lex->select_lex;
lex->yacc_yyss=lex->yacc_yyvs=0;
lex->ignore_space=test(thd->variables.sql_mode & MODE_IGNORE_SPACE);
lex->sql_command= lex->orig_sql_command= SQLCOM_END;
lex->duplicates= DUP_ERROR;
lex->ignore= 0;
lex->sphead= NULL;
lex->spcont= NULL;
lex->proc_list.first= 0;
lex->escape_used= FALSE;
lex->reset_query_tables_list(FALSE);
lex->nest_level=0 ;
lex->allow_sum_func= 0;
lex->in_sum_func= NULL;
DBUG_VOID_RETURN;
}
void lex_end(LEX *lex)
{
DBUG_ENTER("lex_end");
DBUG_PRINT("enter", ("lex: 0x%lx", (long) lex));
x_free(lex->yacc_yyss);
x_free(lex->yacc_yyvs);
DBUG_VOID_RETURN;
}
static int find_keyword(LEX *lex, uint len, bool function)
{
uchar *tok=lex->tok_start;
SYMBOL *symbol = get_hash_symbol((const char *)tok,len,function);
if (symbol)
{
lex->yylval->symbol.symbol=symbol;
lex->yylval->symbol.str= (char*) tok;
lex->yylval->symbol.length=len;
if ((symbol->tok == NOT_SYM) &&
(lex->thd->variables.sql_mode & MODE_HIGH_NOT_PRECEDENCE))
return NOT2_SYM;
if ((symbol->tok == OR_OR_SYM) &&
!(lex->thd->variables.sql_mode & MODE_PIPES_AS_CONCAT))
return OR2_SYM;
return symbol->tok;
}
return 0;
}
/*
Check if name is a keyword
SYNOPSIS
is_keyword()
name checked name (must not be empty)
len length of checked name
RETURN VALUES
0 name is a keyword
1 name isn't a keyword
*/
bool is_keyword(const char *name, uint len)
{
DBUG_ASSERT(len != 0);
return get_hash_symbol(name,len,0)!=0;
}
/* make a copy of token before ptr and set yytoklen */
static LEX_STRING get_token(LEX *lex,uint length)
{
LEX_STRING tmp;
yyUnget(); // ptr points now after last token char
tmp.length=lex->yytoklen=length;
tmp.str=(char*) lex->thd->strmake((char*) lex->tok_start,tmp.length);
return tmp;
}
/*
todo:
There are no dangerous charsets in mysql for function
get_quoted_token yet. But it should be fixed in the
future to operate multichar strings (like ucs2)
*/
static LEX_STRING get_quoted_token(LEX *lex,uint length, char quote)
{
LEX_STRING tmp;
byte *from, *to, *end;
yyUnget(); // ptr points now after last token char
tmp.length=lex->yytoklen=length;
tmp.str=(char*) lex->thd->alloc(tmp.length+1);
for (from= (byte*) lex->tok_start, to= (byte*) tmp.str, end= to+length ;
to != end ;
)
{
if ((*to++= *from++) == quote)
from++; // Skip double quotes
}
*to= 0; // End null for safety
return tmp;
}
/*
Return an unescaped text literal without quotes
Fix sometimes to do only one scan of the string
*/
static char *get_text(LEX *lex)
{
reg1 uchar c,sep;
uint found_escape=0;
CHARSET_INFO *cs= lex->thd->charset();
sep= yyGetLast(); // String should end with this
//lex->tok_start=lex->ptr-1; // Remember '
while (lex->ptr != lex->end_of_query)
{
c = yyGet();
#ifdef USE_MB
int l;
if (use_mb(cs) &&
(l = my_ismbchar(cs,
(const char *)lex->ptr-1,
(const char *)lex->end_of_query))) {
lex->ptr += l-1;
continue;
}
#endif
if (c == '\\' &&
!(lex->thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES))
{ // Escaped character
found_escape=1;
if (lex->ptr == lex->end_of_query)
return 0;
yySkip();
}
else if (c == sep)
{
if (c == yyGet()) // Check if two separators in a row
{
found_escape=1; // dupplicate. Remember for delete
continue;
}
else
yyUnget();
/* Found end. Unescape and return string */
uchar *str,*end,*start;
str=lex->tok_start+1;
end=lex->ptr-1;
if (!(start=(uchar*) lex->thd->alloc((uint) (end-str)+1)))
return (char*) ""; // Sql_alloc has set error flag
if (!found_escape)
{
lex->yytoklen=(uint) (end-str);
memcpy(start,str,lex->yytoklen);
start[lex->yytoklen]=0;
}
else
{
uchar *to;
for (to=start ; str != end ; str++)
{
#ifdef USE_MB
int l;
if (use_mb(cs) &&
(l = my_ismbchar(cs,
(const char *)str, (const char *)end))) {
while (l--)
*to++ = *str++;
str--;
continue;
}
#endif
if (!(lex->thd->variables.sql_mode & MODE_NO_BACKSLASH_ESCAPES) &&
*str == '\\' && str+1 != end)
{
switch(*++str) {
case 'n':
*to++='\n';
break;
case 't':
*to++= '\t';
break;
case 'r':
*to++ = '\r';
break;
case 'b':
*to++ = '\b';
break;
case '0':
*to++= 0; // Ascii null
break;
case 'Z': // ^Z must be escaped on Win32
*to++='\032';
break;
case '_':
case '%':
*to++= '\\'; // remember prefix for wildcard
/* Fall through */
default:
*to++= *str;
break;
}
}
else if (*str == sep)
*to++= *str++; // Two ' or "
else
*to++ = *str;
}
*to=0;
lex->yytoklen=(uint) (to-start);
}
return (char*) start;
}
}
return 0; // unexpected end of query
}
/*
** Calc type of integer; long integer, longlong integer or real.
** Returns smallest type that match the string.
** When using unsigned long long values the result is converted to a real
** because else they will be unexpected sign changes because all calculation
** is done with longlong or double.
*/
static const char *long_str="2147483647";
static const uint long_len=10;
static const char *signed_long_str="-2147483648";
static const char *longlong_str="9223372036854775807";
static const uint longlong_len=19;
static const char *signed_longlong_str="-9223372036854775808";
static const uint signed_longlong_len=19;
static const char *unsigned_longlong_str="18446744073709551615";
static const uint unsigned_longlong_len=20;
static inline uint int_token(const char *str,uint length)
{
if (length < long_len) // quick normal case
return NUM;
bool neg=0;
if (*str == '+') // Remove sign and pre-zeros
{
str++; length--;
}
else if (*str == '-')
{
str++; length--;
neg=1;
}
while (*str == '0' && length)
{
str++; length --;
}
if (length < long_len)
return NUM;
uint smaller,bigger;
const char *cmp;
if (neg)
{
if (length == long_len)
{
cmp= signed_long_str+1;
smaller=NUM; // If <= signed_long_str
bigger=LONG_NUM; // If >= signed_long_str
}
else if (length < signed_longlong_len)
return LONG_NUM;
else if (length > signed_longlong_len)
return DECIMAL_NUM;
else
{
cmp=signed_longlong_str+1;
smaller=LONG_NUM; // If <= signed_longlong_str
bigger=DECIMAL_NUM;
}
}
else
{
if (length == long_len)
{
cmp= long_str;
smaller=NUM;
bigger=LONG_NUM;
}
else if (length < longlong_len)
return LONG_NUM;
else if (length > longlong_len)
{
if (length > unsigned_longlong_len)
return DECIMAL_NUM;
cmp=unsigned_longlong_str;
smaller=ULONGLONG_NUM;
bigger=DECIMAL_NUM;
}
else
{
cmp=longlong_str;
smaller=LONG_NUM;
bigger= ULONGLONG_NUM;
}
}
while (*cmp && *cmp++ == *str++) ;
return ((uchar) str[-1] <= (uchar) cmp[-1]) ? smaller : bigger;
}
/*
MYSQLlex remember the following states from the following MYSQLlex()
- MY_LEX_EOQ Found end of query
- MY_LEX_OPERATOR_OR_IDENT Last state was an ident, text or number
(which can't be followed by a signed number)
*/
int MYSQLlex(void *arg, void *yythd)
{
reg1 uchar c;
int tokval, result_state;
uint length;
enum my_lex_states state;
LEX *lex= ((THD *)yythd)->lex;
YYSTYPE *yylval=(YYSTYPE*) arg;
CHARSET_INFO *cs= ((THD *) yythd)->charset();
uchar *state_map= cs->state_map;
uchar *ident_map= cs->ident_map;
lex->yylval=yylval; // The global state
lex->tok_end_prev= lex->tok_end;
lex->tok_start_prev= lex->tok_start;
lex->tok_start=lex->tok_end=lex->ptr;
state=lex->next_state;
lex->next_state=MY_LEX_OPERATOR_OR_IDENT;
LINT_INIT(c);
for (;;)
{
switch (state) {
case MY_LEX_OPERATOR_OR_IDENT: // Next is operator or keyword
case MY_LEX_START: // Start of token
// Skip startspace
for (c=yyGet() ; (state_map[c] == MY_LEX_SKIP) ; c= yyGet())
{
if (c == '\n')
lex->yylineno++;
}
lex->tok_start=lex->ptr-1; // Start of real token
state= (enum my_lex_states) state_map[c];
break;
case MY_LEX_ESCAPE:
if (yyGet() == 'N')
{ // Allow \N as shortcut for NULL
yylval->lex_str.str=(char*) "\\N";
yylval->lex_str.length=2;
return NULL_SYM;
}
case MY_LEX_CHAR: // Unknown or single char token
case MY_LEX_SKIP: // This should not happen
if (c == '-' && yyPeek() == '-' &&
(my_isspace(cs,yyPeek2()) ||
my_iscntrl(cs,yyPeek2())))
{
state=MY_LEX_COMMENT;
break;
}
yylval->lex_str.str=(char*) (lex->ptr=lex->tok_start);// Set to first chr
yylval->lex_str.length=1;
c=yyGet();
if (c != ')')
lex->next_state= MY_LEX_START; // Allow signed numbers
if (c == ',')
lex->tok_start=lex->ptr; // Let tok_start point at next item
/*
Check for a placeholder: it should not precede a possible identifier
because of binlogging: when a placeholder is replaced with
its value in a query for the binlog, the query must stay
grammatically correct.
*/
else if (c == '?' && lex->stmt_prepare_mode && !ident_map[yyPeek()])
return(PARAM_MARKER);
return((int) c);
case MY_LEX_IDENT_OR_NCHAR:
if (yyPeek() != '\'')
{ // Found x'hex-number'
state= MY_LEX_IDENT;
break;
}
yyGet(); // Skip '
while ((c = yyGet()) && (c !='\'')) ;
length=(lex->ptr - lex->tok_start); // Length of hexnum+3
if (c != '\'')
{
return(ABORT_SYM); // Illegal hex constant
}
yyGet(); // get_token makes an unget
yylval->lex_str=get_token(lex,length);
yylval->lex_str.str+=2; // Skip x'
yylval->lex_str.length-=3; // Don't count x' and last '
lex->yytoklen-=3;
return (NCHAR_STRING);
case MY_LEX_IDENT_OR_HEX:
if (yyPeek() == '\'')
{ // Found x'hex-number'
state= MY_LEX_HEX_NUMBER;
break;
}
case MY_LEX_IDENT_OR_BIN:
if (yyPeek() == '\'')
{ // Found b'bin-number'
state= MY_LEX_BIN_NUMBER;
break;
}
case MY_LEX_IDENT:
uchar *start;
#if defined(USE_MB) && defined(USE_MB_IDENT)
if (use_mb(cs))
{
result_state= IDENT_QUOTED;
if (my_mbcharlen(cs, yyGetLast()) > 1)
{
int l = my_ismbchar(cs,
(const char *)lex->ptr-1,
(const char *)lex->end_of_query);
if (l == 0) {
state = MY_LEX_CHAR;
continue;
}
lex->ptr += l - 1;
}
while (ident_map[c=yyGet()])
{
if (my_mbcharlen(cs, c) > 1)
{
int l;
if ((l = my_ismbchar(cs,
(const char *)lex->ptr-1,
(const char *)lex->end_of_query)) == 0)
break;
lex->ptr += l-1;
}
}
}
else
#endif
{
for (result_state= c; ident_map[c= yyGet()]; result_state|= c);
/* If there were non-ASCII characters, mark that we must convert */
result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
}
length= (uint) (lex->ptr - lex->tok_start)-1;
start= lex->ptr;
if (lex->ignore_space)
{
/*
If we find a space then this can't be an identifier. We notice this
below by checking start != lex->ptr.
*/
for (; state_map[c] == MY_LEX_SKIP ; c= yyGet());
}
if (start == lex->ptr && c == '.' && ident_map[yyPeek()])
lex->next_state=MY_LEX_IDENT_SEP;
else
{ // '(' must follow directly if function
yyUnget();
if ((tokval = find_keyword(lex,length,c == '(')))
{
lex->next_state= MY_LEX_START; // Allow signed numbers
return(tokval); // Was keyword
}
yySkip(); // next state does a unget
}
yylval->lex_str=get_token(lex,length);
/*
Note: "SELECT _bla AS 'alias'"
_bla should be considered as a IDENT if charset haven't been found.
So we don't use MYF(MY_WME) with get_charset_by_csname to avoid
producing an error.
*/
if ((yylval->lex_str.str[0]=='_') &&
(lex->charset=get_charset_by_csname(yylval->lex_str.str+1,
MY_CS_PRIMARY,MYF(0))))
return(UNDERSCORE_CHARSET);
return(result_state); // IDENT or IDENT_QUOTED
case MY_LEX_IDENT_SEP: // Found ident and now '.'
yylval->lex_str.str=(char*) lex->ptr;
yylval->lex_str.length=1;
c=yyGet(); // should be '.'
lex->next_state= MY_LEX_IDENT_START;// Next is an ident (not a keyword)
if (!ident_map[yyPeek()]) // Probably ` or "
lex->next_state= MY_LEX_START;
return((int) c);
case MY_LEX_NUMBER_IDENT: // number or ident which num-start
while (my_isdigit(cs,(c = yyGet()))) ;
if (!ident_map[c])
{ // Can't be identifier
state=MY_LEX_INT_OR_REAL;
break;
}
if (c == 'e' || c == 'E')
{
// The following test is written this way to allow numbers of type 1e1
if (my_isdigit(cs,yyPeek()) ||
(c=(yyGet())) == '+' || c == '-')
{ // Allow 1E+10
if (my_isdigit(cs,yyPeek())) // Number must have digit after sign
{
yySkip();
while (my_isdigit(cs,yyGet())) ;
yylval->lex_str=get_token(lex,yyLength());
return(FLOAT_NUM);
}
}
yyUnget(); /* purecov: inspected */
}
else if (c == 'x' && (lex->ptr - lex->tok_start) == 2 &&
lex->tok_start[0] == '0' )
{ // Varbinary
while (my_isxdigit(cs,(c = yyGet()))) ;
if ((lex->ptr - lex->tok_start) >= 4 && !ident_map[c])
{
yylval->lex_str=get_token(lex,yyLength());
yylval->lex_str.str+=2; // Skip 0x
yylval->lex_str.length-=2;
lex->yytoklen-=2;
return (HEX_NUM);
}
yyUnget();
}
else if (c == 'b' && (lex->ptr - lex->tok_start) == 2 &&
lex->tok_start[0] == '0' )
{ // b'bin-number'
while (my_isxdigit(cs,(c = yyGet()))) ;
if ((lex->ptr - lex->tok_start) >= 4 && !ident_map[c])
{
yylval->lex_str= get_token(lex, yyLength());
yylval->lex_str.str+= 2; // Skip 0x
yylval->lex_str.length-= 2;
lex->yytoklen-= 2;
return (BIN_NUM);
}
yyUnget();
}
// fall through
case MY_LEX_IDENT_START: // We come here after '.'
result_state= IDENT;
#if defined(USE_MB) && defined(USE_MB_IDENT)
if (use_mb(cs))
{
result_state= IDENT_QUOTED;
while (ident_map[c=yyGet()])
{
if (my_mbcharlen(cs, c) > 1)
{
int l;
if ((l = my_ismbchar(cs,
(const char *)lex->ptr-1,
(const char *)lex->end_of_query)) == 0)
break;
lex->ptr += l-1;
}
}
}
else
#endif
{
for (result_state=0; ident_map[c= yyGet()]; result_state|= c);
/* If there were non-ASCII characters, mark that we must convert */
result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
}
if (c == '.' && ident_map[yyPeek()])
lex->next_state=MY_LEX_IDENT_SEP;// Next is '.'
yylval->lex_str= get_token(lex,yyLength());
return(result_state);
case MY_LEX_USER_VARIABLE_DELIMITER: // Found quote char
{
uint double_quotes= 0;
char quote_char= c; // Used char
lex->tok_start=lex->ptr; // Skip first `
while ((c=yyGet()))
{
int length;
if ((length= my_mbcharlen(cs, c)) == 1)
{
if (c == (uchar) NAMES_SEP_CHAR)
break; /* Old .frm format can't handle this char */
if (c == quote_char)
{
if (yyPeek() != quote_char)
break;
c=yyGet();
double_quotes++;
continue;
}
}
#ifdef USE_MB
else if (length < 1)
break; // Error
lex->ptr+= length-1;
#endif
}
if (double_quotes)
yylval->lex_str=get_quoted_token(lex,yyLength() - double_quotes,
quote_char);
else
yylval->lex_str=get_token(lex,yyLength());
if (c == quote_char)
yySkip(); // Skip end `
lex->next_state= MY_LEX_START;
return(IDENT_QUOTED);
}
case MY_LEX_INT_OR_REAL: // Compleat int or incompleat real
if (c != '.')
{ // Found complete integer number.
yylval->lex_str=get_token(lex,yyLength());
return int_token(yylval->lex_str.str,yylval->lex_str.length);
}
// fall through
case MY_LEX_REAL: // Incomplete real number
while (my_isdigit(cs,c = yyGet())) ;
if (c == 'e' || c == 'E')
{
c = yyGet();
if (c == '-' || c == '+')
c = yyGet(); // Skip sign
if (!my_isdigit(cs,c))
{ // No digit after sign
state= MY_LEX_CHAR;
break;
}
while (my_isdigit(cs,yyGet())) ;
yylval->lex_str=get_token(lex,yyLength());
return(FLOAT_NUM);
}
yylval->lex_str=get_token(lex,yyLength());
return(DECIMAL_NUM);
case MY_LEX_HEX_NUMBER: // Found x'hexstring'
yyGet(); // Skip '
while (my_isxdigit(cs,(c = yyGet()))) ;
length=(lex->ptr - lex->tok_start); // Length of hexnum+3
if (!(length & 1) || c != '\'')
{
return(ABORT_SYM); // Illegal hex constant
}
yyGet(); // get_token makes an unget
yylval->lex_str=get_token(lex,length);
yylval->lex_str.str+=2; // Skip x'
yylval->lex_str.length-=3; // Don't count x' and last '
lex->yytoklen-=3;
return (HEX_NUM);
case MY_LEX_BIN_NUMBER: // Found b'bin-string'
yyGet(); // Skip '
while ((c= yyGet()) == '0' || c == '1');
length= (lex->ptr - lex->tok_start); // Length of bin-num + 3
if (c != '\'')
return(ABORT_SYM); // Illegal hex constant
yyGet(); // get_token makes an unget
yylval->lex_str= get_token(lex, length);
yylval->lex_str.str+= 2; // Skip b'
yylval->lex_str.length-= 3; // Don't count b' and last '
lex->yytoklen-= 3;
return (BIN_NUM);
case MY_LEX_CMP_OP: // Incomplete comparison operator
if (state_map[yyPeek()] == MY_LEX_CMP_OP ||
state_map[yyPeek()] == MY_LEX_LONG_CMP_OP)
yySkip();
if ((tokval = find_keyword(lex,(uint) (lex->ptr - lex->tok_start),0)))
{
lex->next_state= MY_LEX_START; // Allow signed numbers
return(tokval);
}
state = MY_LEX_CHAR; // Something fishy found
break;
case MY_LEX_LONG_CMP_OP: // Incomplete comparison operator
if (state_map[yyPeek()] == MY_LEX_CMP_OP ||
state_map[yyPeek()] == MY_LEX_LONG_CMP_OP)
{
yySkip();
if (state_map[yyPeek()] == MY_LEX_CMP_OP)
yySkip();
}
if ((tokval = find_keyword(lex,(uint) (lex->ptr - lex->tok_start),0)))
{
lex->next_state= MY_LEX_START; // Found long op
return(tokval);
}
state = MY_LEX_CHAR; // Something fishy found
break;
case MY_LEX_BOOL:
if (c != yyPeek())
{
state=MY_LEX_CHAR;
break;
}
yySkip();
tokval = find_keyword(lex,2,0); // Is a bool operator
lex->next_state= MY_LEX_START; // Allow signed numbers
return(tokval);
case MY_LEX_STRING_OR_DELIMITER:
if (((THD *) yythd)->variables.sql_mode & MODE_ANSI_QUOTES)
{
state= MY_LEX_USER_VARIABLE_DELIMITER;
break;
}
/* " used for strings */
case MY_LEX_STRING: // Incomplete text string
if (!(yylval->lex_str.str = get_text(lex)))
{
state= MY_LEX_CHAR; // Read char by char
break;
}
yylval->lex_str.length=lex->yytoklen;
return(TEXT_STRING);
case MY_LEX_COMMENT: // Comment
lex->select_lex.options|= OPTION_FOUND_COMMENT;
while ((c = yyGet()) != '\n' && c) ;
yyUnget(); // Safety against eof
state = MY_LEX_START; // Try again
break;
case MY_LEX_LONG_COMMENT: /* Long C comment? */
if (yyPeek() != '*')
{
state=MY_LEX_CHAR; // Probable division
break;
}
yySkip(); // Skip '*'
lex->select_lex.options|= OPTION_FOUND_COMMENT;
if (yyPeek() == '!') // MySQL command in comment
{
ulong version=MYSQL_VERSION_ID;
yySkip();
state=MY_LEX_START;
if (my_isdigit(cs,yyPeek()))
{ // Version number
version=strtol((char*) lex->ptr,(char**) &lex->ptr,10);
}
if (version <= MYSQL_VERSION_ID)
{
lex->in_comment=1;
break;
}
}
while (lex->ptr != lex->end_of_query &&
((c=yyGet()) != '*' || yyPeek() != '/'))
{
if (c == '\n')
lex->yylineno++;
}
if (lex->ptr != lex->end_of_query)
yySkip(); // remove last '/'
state = MY_LEX_START; // Try again
break;
case MY_LEX_END_LONG_COMMENT:
if (lex->in_comment && yyPeek() == '/')
{
yySkip();
lex->in_comment=0;
state=MY_LEX_START;
}
else
state=MY_LEX_CHAR; // Return '*'
break;
case MY_LEX_SET_VAR: // Check if ':='
if (yyPeek() != '=')
{
state=MY_LEX_CHAR; // Return ':'
break;
}
yySkip();
return (SET_VAR);
case MY_LEX_SEMICOLON: // optional line terminator
if (yyPeek())
{
THD* thd= (THD*)yythd;
if ((thd->client_capabilities & CLIENT_MULTI_STATEMENTS) &&
!lex->stmt_prepare_mode)
{
lex->safe_to_cache_query= 0;
lex->found_semicolon=(char*) lex->ptr;
thd->server_status|= SERVER_MORE_RESULTS_EXISTS;
lex->next_state= MY_LEX_END;
return (END_OF_INPUT);
}
state= MY_LEX_CHAR; // Return ';'
break;
}
/* fall true */
case MY_LEX_EOL:
if (lex->ptr >= lex->end_of_query)
{
lex->next_state=MY_LEX_END; // Mark for next loop
return(END_OF_INPUT);
}
state=MY_LEX_CHAR;
break;
case MY_LEX_END:
lex->next_state=MY_LEX_END;
return(0); // We found end of input last time
/* Actually real shouldn't start with . but allow them anyhow */
case MY_LEX_REAL_OR_POINT:
if (my_isdigit(cs,yyPeek()))
state = MY_LEX_REAL; // Real
else
{
state= MY_LEX_IDENT_SEP; // return '.'
yyUnget(); // Put back '.'
}
break;
case MY_LEX_USER_END: // end '@' of user@hostname
switch (state_map[yyPeek()]) {
case MY_LEX_STRING:
case MY_LEX_USER_VARIABLE_DELIMITER:
case MY_LEX_STRING_OR_DELIMITER:
break;
case MY_LEX_USER_END:
lex->next_state=MY_LEX_SYSTEM_VAR;
break;
default:
lex->next_state=MY_LEX_HOSTNAME;
break;
}
yylval->lex_str.str=(char*) lex->ptr;
yylval->lex_str.length=1;
return((int) '@');
case MY_LEX_HOSTNAME: // end '@' of user@hostname
for (c=yyGet() ;
my_isalnum(cs,c) || c == '.' || c == '_' || c == '$';
c= yyGet()) ;
yylval->lex_str=get_token(lex,yyLength());
return(LEX_HOSTNAME);
case MY_LEX_SYSTEM_VAR:
yylval->lex_str.str=(char*) lex->ptr;
yylval->lex_str.length=1;
yySkip(); // Skip '@'
lex->next_state= (state_map[yyPeek()] ==
MY_LEX_USER_VARIABLE_DELIMITER ?
MY_LEX_OPERATOR_OR_IDENT :
MY_LEX_IDENT_OR_KEYWORD);
return((int) '@');
case MY_LEX_IDENT_OR_KEYWORD:
/*
We come here when we have found two '@' in a row.
We should now be able to handle:
[(global | local | session) .]variable_name
*/
for (result_state= 0; ident_map[c= yyGet()]; result_state|= c);
/* If there were non-ASCII characters, mark that we must convert */
result_state= result_state & 0x80 ? IDENT_QUOTED : IDENT;
if (c == '.')
lex->next_state=MY_LEX_IDENT_SEP;
length= (uint) (lex->ptr - lex->tok_start)-1;
if ((tokval= find_keyword(lex,length,0)))
{
yyUnget(); // Put back 'c'
return(tokval); // Was keyword
}
yylval->lex_str=get_token(lex,length);
return(result_state);
}
}
}
/*
st_select_lex structures initialisations
*/
void st_select_lex_node::init_query()
{
options= 0;
linkage= UNSPECIFIED_TYPE;
no_error= no_table_names_allowed= 0;
uncacheable= 0;
}
void st_select_lex_node::init_select()
{
}
void st_select_lex_unit::init_query()
{
st_select_lex_node::init_query();
linkage= GLOBAL_OPTIONS_TYPE;
global_parameters= first_select();
select_limit_cnt= HA_POS_ERROR;
offset_limit_cnt= 0;
union_distinct= 0;
prepared= optimized= executed= 0;
item= 0;
union_result= 0;
table= 0;
fake_select_lex= 0;
cleaned= 0;
item_list.empty();
describe= 0;
found_rows_for_union= 0;
}
void st_select_lex::init_query()
{
st_select_lex_node::init_query();
table_list.empty();
top_join_list.empty();
join_list= &top_join_list;
embedding= leaf_tables= 0;
item_list.empty();
join= 0;
having= prep_having= where= prep_where= 0;
olap= UNSPECIFIED_OLAP_TYPE;
having_fix_field= 0;
context.select_lex= this;
context.init();
/*
Add the name resolution context of the current (sub)query to the
stack of contexts for the whole query.
TODO:
push_context may return an error if there is no memory for a new
element in the stack, however this method has no return value,
thus push_context should be moved to a place where query
initialization is checked for failure.
*/
parent_lex->push_context(&context);
cond_count= with_wild= 0;
conds_processed_with_permanent_arena= 0;
ref_pointer_array= 0;
select_n_having_items= 0;
subquery_in_having= explicit_limit= 0;
is_item_list_lookup= 0;
first_execution= 1;
first_cond_optimization= 1;
parsing_place= NO_MATTER;
exclude_from_table_unique_test= no_wrap_view_item= FALSE;
nest_level= 0;
link_next= 0;
}
void st_select_lex::init_select()
{
st_select_lex_node::init_select();
group_list.empty();
type= db= 0;
having= 0;
use_index_ptr= ignore_index_ptr= 0;
table_join_options= 0;
in_sum_expr= with_wild= 0;
options= 0;
braces= 0;
when_list.empty();
expr_list.empty();
interval_list.empty();
use_index.empty();
ftfunc_list_alloc.empty();
inner_sum_func_list= 0;
ftfunc_list= &ftfunc_list_alloc;
linkage= UNSPECIFIED_TYPE;
order_list.elements= 0;
order_list.first= 0;
order_list.next= (byte**) &order_list.first;
/* Set limit and offset to default values */
select_limit= 0; /* denotes the default limit = HA_POS_ERROR */
offset_limit= 0; /* denotes the default offset = 0 */
with_sum_func= 0;
}
/*
st_select_lex structures linking
*/
/* include on level down */
void st_select_lex_node::include_down(st_select_lex_node *upper)
{
if ((next= upper->slave))
next->prev= &next;
prev= &upper->slave;
upper->slave= this;
master= upper;
slave= 0;
}
/*
include on level down (but do not link)
SYNOPSYS
st_select_lex_node::include_standalone()
upper - reference on node underr which this node should be included
ref - references on reference on this node
*/
void st_select_lex_node::include_standalone(st_select_lex_node *upper,
st_select_lex_node **ref)
{
next= 0;
prev= ref;
master= upper;
slave= 0;
}
/* include neighbour (on same level) */
void st_select_lex_node::include_neighbour(st_select_lex_node *before)
{
if ((next= before->next))
next->prev= &next;
prev= &before->next;
before->next= this;
master= before->master;
slave= 0;
}
/* including in global SELECT_LEX list */
void st_select_lex_node::include_global(st_select_lex_node **plink)
{
if ((link_next= *plink))
link_next->link_prev= &link_next;
link_prev= plink;
*plink= this;
}
//excluding from global list (internal function)
void st_select_lex_node::fast_exclude()
{
if (link_prev)
{
if ((*link_prev= link_next))
link_next->link_prev= link_prev;
}
// Remove slave structure
for (; slave; slave= slave->next)
slave->fast_exclude();
}
/*
excluding select_lex structure (except first (first select can't be
deleted, because it is most upper select))
*/
void st_select_lex_node::exclude()
{
//exclude from global list
fast_exclude();
//exclude from other structures
if ((*prev= next))
next->prev= prev;
/*
We do not need following statements, because prev pointer of first
list element point to master->slave
if (master->slave == this)
master->slave= next;
*/
}
/*
Exclude level of current unit from tree of SELECTs
SYNOPSYS
st_select_lex_unit::exclude_level()
NOTE: units which belong to current will be brought up on level of
currernt unit
*/
void st_select_lex_unit::exclude_level()
{
SELECT_LEX_UNIT *units= 0, **units_last= &units;
for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
{
// unlink current level from global SELECTs list
if (sl->link_prev && (*sl->link_prev= sl->link_next))
sl->link_next->link_prev= sl->link_prev;
// bring up underlay levels
SELECT_LEX_UNIT **last= 0;
for (SELECT_LEX_UNIT *u= sl->first_inner_unit(); u; u= u->next_unit())
{
u->master= master;
last= (SELECT_LEX_UNIT**)&(u->next);
}
if (last)
{
(*units_last)= sl->first_inner_unit();
units_last= last;
}
}
if (units)
{
// include brought up levels in place of current
(*prev)= units;
(*units_last)= (SELECT_LEX_UNIT*)next;
if (next)
next->prev= (SELECT_LEX_NODE**)units_last;
units->prev= prev;
}
else
{
// exclude currect unit from list of nodes
(*prev)= next;
if (next)
next->prev= prev;
}
}
/*
Exclude subtree of current unit from tree of SELECTs
SYNOPSYS
st_select_lex_unit::exclude_tree()
*/
void st_select_lex_unit::exclude_tree()
{
for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
{
// unlink current level from global SELECTs list
if (sl->link_prev && (*sl->link_prev= sl->link_next))
sl->link_next->link_prev= sl->link_prev;
// unlink underlay levels
for (SELECT_LEX_UNIT *u= sl->first_inner_unit(); u; u= u->next_unit())
{
u->exclude_level();
}
}
// exclude currect unit from list of nodes
(*prev)= next;
if (next)
next->prev= prev;
}
/*
st_select_lex_node::mark_as_dependent mark all st_select_lex struct from
this to 'last' as dependent
SYNOPSIS
last - pointer to last st_select_lex struct, before wich all
st_select_lex have to be marked as dependent
NOTE
'last' should be reachable from this st_select_lex_node
*/
void st_select_lex::mark_as_dependent(SELECT_LEX *last)
{
/*
Mark all selects from resolved to 1 before select where was
found table as depended (of select where was found table)
*/
for (SELECT_LEX *s= this;
s && s != last;
s= s->outer_select())
if (!(s->uncacheable & UNCACHEABLE_DEPENDENT))
{
// Select is dependent of outer select
s->uncacheable|= UNCACHEABLE_DEPENDENT;
SELECT_LEX_UNIT *munit= s->master_unit();
munit->uncacheable|= UNCACHEABLE_DEPENDENT;
}
}
bool st_select_lex_node::set_braces(bool value) { return 1; }
bool st_select_lex_node::inc_in_sum_expr() { return 1; }
uint st_select_lex_node::get_in_sum_expr() { return 0; }
TABLE_LIST* st_select_lex_node::get_table_list() { return 0; }
List<Item>* st_select_lex_node::get_item_list() { return 0; }
List<String>* st_select_lex_node::get_use_index() { return 0; }
List<String>* st_select_lex_node::get_ignore_index() { return 0; }
TABLE_LIST *st_select_lex_node::add_table_to_list(THD *thd, Table_ident *table,
LEX_STRING *alias,
ulong table_join_options,
thr_lock_type flags,
List<String> *use_index,
List<String> *ignore_index,
LEX_STRING *option)
{
return 0;
}
ulong st_select_lex_node::get_table_join_options()
{
return 0;
}
/*
prohibit using LIMIT clause
*/
bool st_select_lex::test_limit()
{
if (select_limit != 0)
{
my_error(ER_NOT_SUPPORTED_YET, MYF(0),
"LIMIT & IN/ALL/ANY/SOME subquery");
return(1);
}
// no sense in ORDER BY without LIMIT
order_list.empty();
return(0);
}
st_select_lex_unit* st_select_lex_unit::master_unit()
{
return this;
}
st_select_lex* st_select_lex_unit::outer_select()
{
return (st_select_lex*) master;
}
bool st_select_lex::add_order_to_list(THD *thd, Item *item, bool asc)
{
return add_to_list(thd, order_list, item, asc);
}
bool st_select_lex::add_item_to_list(THD *thd, Item *item)
{
DBUG_ENTER("st_select_lex::add_item_to_list");
DBUG_PRINT("info", ("Item: %p", item));
DBUG_RETURN(item_list.push_back(item));
}
bool st_select_lex::add_group_to_list(THD *thd, Item *item, bool asc)
{
return add_to_list(thd, group_list, item, asc);
}
bool st_select_lex::add_ftfunc_to_list(Item_func_match *func)
{
return !func || ftfunc_list->push_back(func); // end of memory?
}
st_select_lex_unit* st_select_lex::master_unit()
{
return (st_select_lex_unit*) master;
}
st_select_lex* st_select_lex::outer_select()
{
return (st_select_lex*) master->get_master();
}
bool st_select_lex::set_braces(bool value)
{
braces= value;
return 0;
}
bool st_select_lex::inc_in_sum_expr()
{
in_sum_expr++;
return 0;
}
uint st_select_lex::get_in_sum_expr()
{
return in_sum_expr;
}
TABLE_LIST* st_select_lex::get_table_list()
{
return (TABLE_LIST*) table_list.first;
}
List<Item>* st_select_lex::get_item_list()
{
return &item_list;
}
List<String>* st_select_lex::get_use_index()
{
return use_index_ptr;
}
List<String>* st_select_lex::get_ignore_index()
{
return ignore_index_ptr;
}
ulong st_select_lex::get_table_join_options()
{
return table_join_options;
}
bool st_select_lex::setup_ref_array(THD *thd, uint order_group_num)
{
if (ref_pointer_array)
return 0;
/*
We have to create array in prepared statement memory if it is
prepared statement
*/
Query_arena *arena= thd->stmt_arena;
return (ref_pointer_array=
(Item **)arena->alloc(sizeof(Item*) *
(item_list.elements +
select_n_having_items +
order_group_num)* 5)) == 0;
}
void st_select_lex_unit::print(String *str)
{
bool union_all= !union_distinct;
for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
{
if (sl != first_select())
{
str->append(STRING_WITH_LEN(" union "));
if (union_all)
str->append(STRING_WITH_LEN("all "));
else if (union_distinct == sl)
union_all= TRUE;
}
if (sl->braces)
str->append('(');
sl->print(thd, str);
if (sl->braces)
str->append(')');
}
if (fake_select_lex == global_parameters)
{
if (fake_select_lex->order_list.elements)
{
str->append(STRING_WITH_LEN(" order by "));
fake_select_lex->print_order(str,
(ORDER *) fake_select_lex->
order_list.first);
}
fake_select_lex->print_limit(thd, str);
}
}
void st_select_lex::print_order(String *str, ORDER *order)
{
for (; order; order= order->next)
{
if (order->counter_used)
{
char buffer[20];
uint length= my_snprintf(buffer, 20, "%d", order->counter);
str->append(buffer, length);
}
else
(*order->item)->print(str);
if (!order->asc)
str->append(STRING_WITH_LEN(" desc"));
if (order->next)
str->append(',');
}
}
void st_select_lex::print_limit(THD *thd, String *str)
{
SELECT_LEX_UNIT *unit= master_unit();
Item_subselect *item= unit->item;
if (item && unit->global_parameters == this &&
(item->substype() == Item_subselect::EXISTS_SUBS ||
item->substype() == Item_subselect::IN_SUBS ||
item->substype() == Item_subselect::ALL_SUBS))
{
DBUG_ASSERT(!item->fixed ||
select_limit->val_int() == LL(1) && offset_limit == 0);
return;
}
if (explicit_limit)
{
str->append(STRING_WITH_LEN(" limit "));
if (offset_limit)
{
offset_limit->print(str);
str->append(',');
}
select_limit->print(str);
}
}
/*
Initialize (or reset) Query_tables_list object.
SYNOPSIS
reset_query_tables_list()
init TRUE - we should perform full initialization of object with
allocating needed memory
FALSE - object is already initialized so we should only reset
its state so it can be used for parsing/processing
of new statement
DESCRIPTION
This method initializes Query_tables_list so it can be used as part
of LEX object for parsing/processing of statement. One can also use
this method to reset state of already initialized Query_tables_list
so it can be used for processing of new statement.
*/
void Query_tables_list::reset_query_tables_list(bool init)
{
query_tables= 0;
query_tables_last= &query_tables;
query_tables_own_last= 0;
if (init)
hash_init(&sroutines, system_charset_info, 0, 0, 0, sp_sroutine_key, 0, 0);
else if (sroutines.records)
my_hash_reset(&sroutines);
sroutines_list.empty();
sroutines_list_own_last= sroutines_list.next;
sroutines_list_own_elements= 0;
}
/*
Destroy Query_tables_list object with freeing all resources used by it.
SYNOPSIS
destroy_query_tables_list()
*/
void Query_tables_list::destroy_query_tables_list()
{
hash_free(&sroutines);
}
/*
Initialize LEX object.
SYNOPSIS
st_lex::st_lex()
NOTE
LEX object initialized with this constructor can be used as part of
THD object for which one can safely call open_tables(), lock_tables()
and close_thread_tables() functions. But it is not yet ready for
statement parsing. On should use lex_start() function to prepare LEX
for this.
*/
st_lex::st_lex()
:result(0), yacc_yyss(0), yacc_yyvs(0),
sql_command(SQLCOM_END)
{
reset_query_tables_list(TRUE);
}
/*
Check whether the merging algorithm can be used on this VIEW
SYNOPSIS
st_lex::can_be_merged()
DESCRIPTION
We can apply merge algorithm if it is single SELECT view with
subqueries only in WHERE clause (we do not count SELECTs of underlying
views, and second level subqueries) and we have not grpouping, ordering,
HAVING clause, aggregate functions, DISTINCT clause, LIMIT clause and
several underlying tables.
RETURN
FALSE - only temporary table algorithm can be used
TRUE - merge algorithm can be used
*/
bool st_lex::can_be_merged()
{
// TODO: do not forget implement case when select_lex.table_list.elements==0
/* find non VIEW subqueries/unions */
bool selects_allow_merge= select_lex.next_select() == 0;
if (selects_allow_merge)
{
for (SELECT_LEX_UNIT *unit= select_lex.first_inner_unit();
unit;
unit= unit->next_unit())
{
if (unit->first_select()->parent_lex == this &&
(unit->item == 0 || unit->item->place() != IN_WHERE))
{
selects_allow_merge= 0;
break;
}
}
}
return (selects_allow_merge &&
select_lex.order_list.elements == 0 &&
select_lex.group_list.elements == 0 &&
select_lex.having == 0 &&
select_lex.with_sum_func == 0 &&
select_lex.table_list.elements >= 1 &&
!(select_lex.options & SELECT_DISTINCT) &&
select_lex.select_limit == 0);
}
/*
check if command can use VIEW with MERGE algorithm (for top VIEWs)
SYNOPSIS
st_lex::can_use_merged()
DESCRIPTION
Only listed here commands can use merge algorithm in top level
SELECT_LEX (for subqueries will be used merge algorithm if
st_lex::can_not_use_merged() is not TRUE).
RETURN
FALSE - command can't use merged VIEWs
TRUE - VIEWs with MERGE algorithms can be used
*/
bool st_lex::can_use_merged()
{
switch (sql_command)
{
case SQLCOM_SELECT:
case SQLCOM_CREATE_TABLE:
case SQLCOM_UPDATE:
case SQLCOM_UPDATE_MULTI:
case SQLCOM_DELETE:
case SQLCOM_DELETE_MULTI:
case SQLCOM_INSERT:
case SQLCOM_INSERT_SELECT:
case SQLCOM_REPLACE:
case SQLCOM_REPLACE_SELECT:
case SQLCOM_LOAD:
return TRUE;
default:
return FALSE;
}
}
/*
Check if command can't use merged views in any part of command
SYNOPSIS
st_lex::can_not_use_merged()
DESCRIPTION
Temporary table algorithm will be used on all SELECT levels for queries
listed here (see also st_lex::can_use_merged()).
RETURN
FALSE - command can't use merged VIEWs
TRUE - VIEWs with MERGE algorithms can be used
*/
bool st_lex::can_not_use_merged()
{
switch (sql_command)
{
case SQLCOM_CREATE_VIEW:
case SQLCOM_SHOW_CREATE:
/*
SQLCOM_SHOW_FIELDS is necessary to make
information schema tables working correctly with views.
see get_schema_tables_result function
*/
case SQLCOM_SHOW_FIELDS:
return TRUE;
default:
return FALSE;
}
}
/*
Detect that we need only table structure of derived table/view
SYNOPSIS
only_view_structure()
RETURN
TRUE yes, we need only structure
FALSE no, we need data
*/
bool st_lex::only_view_structure()
{
switch (sql_command) {
case SQLCOM_SHOW_CREATE:
case SQLCOM_SHOW_TABLES:
case SQLCOM_SHOW_FIELDS:
case SQLCOM_REVOKE_ALL:
case SQLCOM_REVOKE:
case SQLCOM_GRANT:
case SQLCOM_CREATE_VIEW:
return TRUE;
default:
return FALSE;
}
}
/*
Should Items_ident be printed correctly
SYNOPSIS
need_correct_ident()
RETURN
TRUE yes, we need only structure
FALSE no, we need data
*/
bool st_lex::need_correct_ident()
{
switch(sql_command)
{
case SQLCOM_SHOW_CREATE:
case SQLCOM_SHOW_TABLES:
case SQLCOM_CREATE_VIEW:
return TRUE;
default:
return FALSE;
}
}
/*
Get effective type of CHECK OPTION for given view
SYNOPSIS
get_effective_with_check()
view given view
NOTE
It have not sense to set CHECK OPTION for SELECT satement or subqueries,
so we do not.
RETURN
VIEW_CHECK_NONE no need CHECK OPTION
VIEW_CHECK_LOCAL CHECK OPTION LOCAL
VIEW_CHECK_CASCADED CHECK OPTION CASCADED
*/
uint8 st_lex::get_effective_with_check(st_table_list *view)
{
if (view->select_lex->master_unit() == &unit &&
which_check_option_applicable())
return (uint8)view->with_check;
return VIEW_CHECK_NONE;
}
/*
initialize limit counters
SYNOPSIS
st_select_lex_unit::set_limit()
values - SELECT_LEX with initial values for counters
*/
void st_select_lex_unit::set_limit(SELECT_LEX *sl)
{
ha_rows select_limit_val;
DBUG_ASSERT(! thd->stmt_arena->is_stmt_prepare());
select_limit_val= (ha_rows)(sl->select_limit ? sl->select_limit->val_uint() :
HA_POS_ERROR);
offset_limit_cnt= (ha_rows)(sl->offset_limit ? sl->offset_limit->val_uint() :
ULL(0));
select_limit_cnt= select_limit_val + offset_limit_cnt;
if (select_limit_cnt < select_limit_val)
select_limit_cnt= HA_POS_ERROR; // no limit
}
/*
Unlink the first table from the global table list and the first table from
outer select (lex->select_lex) local list
SYNOPSIS
unlink_first_table()
link_to_local Set to 1 if caller should link this table to local list
NOTES
We assume that first tables in both lists is the same table or the local
list is empty.
RETURN
0 If 'query_tables' == 0
unlinked table
In this case link_to_local is set.
*/
TABLE_LIST *st_lex::unlink_first_table(bool *link_to_local)
{
TABLE_LIST *first;
if ((first= query_tables))
{
/*
Exclude from global table list
*/
if ((query_tables= query_tables->next_global))
query_tables->prev_global= &query_tables;
else
query_tables_last= &query_tables;
first->next_global= 0;
/*
and from local list if it is not empty
*/
if ((*link_to_local= test(select_lex.table_list.first)))
{
select_lex.context.table_list=
select_lex.context.first_name_resolution_table= first->next_local;
select_lex.table_list.first= (byte*) (first->next_local);
select_lex.table_list.elements--; //safety
first->next_local= 0;
/*
Ensure that the global list has the same first table as the local
list.
*/
first_lists_tables_same();
}
}
return first;
}
/*
Bring first local table of first most outer select to first place in global
table list
SYNOPSYS
st_lex::first_lists_tables_same()
NOTES
In many cases (for example, usual INSERT/DELETE/...) the first table of
main SELECT_LEX have special meaning => check that it is the first table
in global list and re-link to be first in the global list if it is
necessary. We need such re-linking only for queries with sub-queries in
the select list, as only in this case tables of sub-queries will go to
the global list first.
*/
void st_lex::first_lists_tables_same()
{
TABLE_LIST *first_table= (TABLE_LIST*) select_lex.table_list.first;
if (query_tables != first_table && first_table != 0)
{
TABLE_LIST *next;
if (query_tables_last == &first_table->next_global)
query_tables_last= first_table->prev_global;
if ((next= *first_table->prev_global= first_table->next_global))
next->prev_global= first_table->prev_global;
/* include in new place */
first_table->next_global= query_tables;
/*
We are sure that query_tables is not 0, because first_table was not
first table in the global list => we can use
query_tables->prev_global without check of query_tables
*/
query_tables->prev_global= &first_table->next_global;
first_table->prev_global= &query_tables;
query_tables= first_table;
}
}
/*
Add implicitly used time zone description tables to global table list
(if needed).
SYNOPSYS
st_lex::add_time_zone_tables_to_query_tables()
thd - pointer to current thread context
RETURN VALUE
TRUE - error
FALSE - success
*/
bool st_lex::add_time_zone_tables_to_query_tables(THD *thd)
{
/* We should not add these tables twice */
if (!time_zone_tables_used)
{
time_zone_tables_used= my_tz_get_table_list(thd, &query_tables_last);
if (time_zone_tables_used == &fake_time_zone_tables_list)
return TRUE;
}
return FALSE;
}
/*
Link table back that was unlinked with unlink_first_table()
SYNOPSIS
link_first_table_back()
link_to_local do we need link this table to local
RETURN
global list
*/
void st_lex::link_first_table_back(TABLE_LIST *first,
bool link_to_local)
{
if (first)
{
if ((first->next_global= query_tables))
query_tables->prev_global= &first->next_global;
else
query_tables_last= &first->next_global;
query_tables= first;
if (link_to_local)
{
first->next_local= (TABLE_LIST*) select_lex.table_list.first;
select_lex.context.table_list= first;
select_lex.table_list.first= (byte*) first;
select_lex.table_list.elements++; //safety
}
}
}
/*
cleanup lex for case when we open table by table for processing
SYNOPSIS
st_lex::cleanup_after_one_table_open()
NOTE
This method is mostly responsible for cleaning up of selects lists and
derived tables state. To rollback changes in Query_tables_list one has
to call Query_tables_list::reset_query_tables_list(FALSE).
*/
void st_lex::cleanup_after_one_table_open()
{
/*
thd->lex->derived_tables & additional units may be set if we open
a view. It is necessary to clear thd->lex->derived_tables flag
to prevent processing of derived tables during next open_and_lock_tables
if next table is a real table and cleanup & remove underlying units
NOTE: all units will be connected to thd->lex->select_lex, because we
have not UNION on most upper level.
*/
if (all_selects_list != &select_lex)
{
derived_tables= 0;
/* cleunup underlying units (units of VIEW) */
for (SELECT_LEX_UNIT *un= select_lex.first_inner_unit();
un;
un= un->next_unit())
un->cleanup();
/* reduce all selects list to default state */
all_selects_list= &select_lex;
/* remove underlying units (units of VIEW) subtree */
select_lex.cut_subtree();
}
time_zone_tables_used= 0;
}
/*
Save current state of Query_tables_list for this LEX, and prepare it
for processing of new statemnt.
SYNOPSIS
reset_n_backup_query_tables_list()
backup Pointer to Query_tables_list instance to be used for backup
*/
void st_lex::reset_n_backup_query_tables_list(Query_tables_list *backup)
{
backup->set_query_tables_list(this);
/*
We have to perform full initialization here since otherwise we
will damage backed up state.
*/
this->reset_query_tables_list(TRUE);
}
/*
Restore state of Query_tables_list for this LEX from backup.
SYNOPSIS
restore_backup_query_tables_list()
backup Pointer to Query_tables_list instance used for backup
*/
void st_lex::restore_backup_query_tables_list(Query_tables_list *backup)
{
this->destroy_query_tables_list();
this->set_query_tables_list(backup);
}
/*
Do end-of-prepare fixup for list of tables and their merge-VIEWed tables
SYNOPSIS
fix_prepare_info_in_table_list()
thd Thread handle
tbl List of tables to process
DESCRIPTION
Perform end-end-of prepare fixup for list of tables, if any of the tables
is a merge-algorithm VIEW, recursively fix up its underlying tables as
well.
*/
static void fix_prepare_info_in_table_list(THD *thd, TABLE_LIST *tbl)
{
for (; tbl; tbl= tbl->next_local)
{
if (tbl->on_expr)
{
tbl->prep_on_expr= tbl->on_expr;
tbl->on_expr= tbl->on_expr->copy_andor_structure(thd);
}
fix_prepare_info_in_table_list(thd, tbl->merge_underlying_list);
}
}
/*
fix some structures at the end of preparation
SYNOPSIS
st_select_lex::fix_prepare_information
thd thread handler
conds pointer on conditions which will be used for execution statement
*/
void st_select_lex::fix_prepare_information(THD *thd, Item **conds)
{
if (!thd->stmt_arena->is_conventional() && first_execution)
{
first_execution= 0;
if (*conds)
{
prep_where= *conds;
*conds= where= prep_where->copy_andor_structure(thd);
}
fix_prepare_info_in_table_list(thd, (TABLE_LIST *)table_list.first);
}
}
/*
There are st_select_lex::add_table_to_list &
st_select_lex::set_lock_for_tables are in sql_parse.cc
st_select_lex::print is in sql_select.cc
st_select_lex_unit::prepare, st_select_lex_unit::exec,
st_select_lex_unit::cleanup, st_select_lex_unit::reinit_exec_mechanism,
st_select_lex_unit::change_result
are in sql_union.cc
*/
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