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mariadb/sql/sql_prepare.cc
konstantin@mysql.com bef558b7ee - a fix for Bug#11458 "Prepared statement with subselects return random 
data": remove the fix for another bug (8807) that
added OUTER_REF_TABLE_BIT to all subqueries that used a placeholder
to prevent their evaluation at prepare. As this bit hanged in 
Item_subselect::used_tables_cache for ever, a constant subquery with
a placeholder was never evaluated as such, which caused wrong 
choice of the execution plan for the statement.
- to fix Bug#8807 backport a better fix from 5.0
- post-review fixes.
2005-07-13 17:38:55 +04:00

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/* Copyright (C) 1995-2002 MySQL 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 */
/**********************************************************************
This file contains the implementation of prepare and executes.
Prepare:
- Server gets the query from client with command 'COM_PREPARE';
in the following format:
[COM_PREPARE:1] [query]
- Parse the query and recognize any parameter markers '?' and
store its information list in lex->param_list
- Allocate a new statement for this prepare; and keep this in
'thd->prepared_statements' pool.
- Without executing the query, return back to client the total
number of parameters along with result-set metadata information
(if any) in the following format:
[STMT_ID:4]
[Column_count:2]
[Param_count:2]
[Columns meta info] (if Column_count > 0)
[Params meta info] (if Param_count > 0 ) (TODO : 4.1.1)
Prepare-execute:
- Server gets the command 'COM_EXECUTE' to execute the
previously prepared query. If there is any param markers; then client
will send the data in the following format:
[COM_EXECUTE:1]
[STMT_ID:4]
[NULL_BITS:(param_count+7)/8)]
[TYPES_SUPPLIED_BY_CLIENT(0/1):1]
[[length]data]
[[length]data] .. [[length]data].
(Note: Except for string/binary types; all other types will not be
supplied with length field)
- Replace the param items with this new data. If it is a first execute
or types altered by client; then setup the conversion routines.
- Execute the query without re-parsing and send back the results
to client
Long data handling:
- Server gets the long data in pieces with command type 'COM_LONG_DATA'.
- The packet recieved will have the format as:
[COM_LONG_DATA:1][STMT_ID:4][parameter_number:2][data]
- data from the packet is appended to long data value buffer for this
placeholder.
- It's up to the client to check for read data ended. The server doesn't
care; and also server doesn't notify to the client that it got the
data or not; if there is any error; then during execute; the error
will be returned
***********************************************************************/
#include "mysql_priv.h"
#include "sql_select.h" // for JOIN
#include <m_ctype.h> // for isspace()
#ifdef EMBEDDED_LIBRARY
/* include MYSQL_BIND headers */
#include <mysql.h>
#endif
/******************************************************************************
Prepared_statement: statement which can contain placeholders
******************************************************************************/
class Prepared_statement: public Statement
{
public:
THD *thd;
Item_param **param_array;
uint param_count;
uint last_errno;
char last_error[MYSQL_ERRMSG_SIZE];
#ifndef EMBEDDED_LIBRARY
bool (*set_params)(Prepared_statement *st, uchar *data, uchar *data_end,
uchar *read_pos, String *expanded_query);
#else
bool (*set_params_data)(Prepared_statement *st, String *expanded_query);
#endif
bool (*set_params_from_vars)(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *expanded_query);
public:
Prepared_statement(THD *thd_arg);
virtual ~Prepared_statement();
void setup_set_params();
virtual Item_arena::Type type() const;
};
static void execute_stmt(THD *thd, Prepared_statement *stmt,
String *expanded_query, bool set_context);
/******************************************************************************
Implementation
******************************************************************************/
inline bool is_param_null(const uchar *pos, ulong param_no)
{
return pos[param_no/8] & (1 << (param_no & 7));
}
enum { STMT_QUERY_LOG_LENGTH= 8192 };
enum enum_send_error { DONT_SEND_ERROR= 0, SEND_ERROR };
/*
Seek prepared statement in statement map by id: returns zero if statement
was not found, pointer otherwise.
*/
static Prepared_statement *
find_prepared_statement(THD *thd, ulong id, const char *where,
enum enum_send_error se)
{
Statement *stmt= thd->stmt_map.find(id);
if (stmt == 0 || stmt->type() != Item_arena::PREPARED_STATEMENT)
{
char llbuf[22];
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), 22, llstr(id, llbuf), where);
if (se == SEND_ERROR)
send_error(thd);
return 0;
}
return (Prepared_statement *) stmt;
}
/*
Send prepared stmt info to client after prepare
*/
#ifndef EMBEDDED_LIBRARY
static bool send_prep_stmt(Prepared_statement *stmt, uint columns)
{
NET *net= &stmt->thd->net;
char buff[9];
DBUG_ENTER("send_prep_stmt");
buff[0]= 0; /* OK packet indicator */
int4store(buff+1, stmt->id);
int2store(buff+5, columns);
int2store(buff+7, stmt->param_count);
/*
Send types and names of placeholders to the client
XXX: fix this nasty upcast from List<Item_param> to List<Item>
*/
DBUG_RETURN(my_net_write(net, buff, sizeof(buff)) ||
(stmt->param_count &&
stmt->thd->protocol_simple.send_fields((List<Item> *)
&stmt->lex->param_list,
0)));
}
#else
static bool send_prep_stmt(Prepared_statement *stmt,
uint columns __attribute__((unused)))
{
THD *thd= stmt->thd;
thd->client_stmt_id= stmt->id;
thd->client_param_count= stmt->param_count;
thd->net.last_errno= 0;
return 0;
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Read the length of the parameter data and return back to
caller by positing the pointer to param data.
*/
#ifndef EMBEDDED_LIBRARY
static ulong get_param_length(uchar **packet, ulong len)
{
reg1 uchar *pos= *packet;
if (len < 1)
return 0;
if (*pos < 251)
{
(*packet)++;
return (ulong) *pos;
}
if (len < 3)
return 0;
if (*pos == 252)
{
(*packet)+=3;
return (ulong) uint2korr(pos+1);
}
if (len < 4)
return 0;
if (*pos == 253)
{
(*packet)+=4;
return (ulong) uint3korr(pos+1);
}
if (len < 5)
return 0;
(*packet)+=9; // Must be 254 when here
/*
In our client-server protocol all numbers bigger than 2^24
stored as 8 bytes with uint8korr. Here we always know that
parameter length is less than 2^4 so don't look at the second
4 bytes. But still we need to obey the protocol hence 9 in the
assignment above.
*/
return (ulong) uint4korr(pos+1);
}
#else
#define get_param_length(packet, len) len
#endif /*!EMBEDDED_LIBRARY*/
/*
Data conversion routines
SYNOPSIS
set_param_xx()
param parameter item
pos input data buffer
len length of data in the buffer
All these functions read the data from pos, convert it to requested type
and assign to param; pos is advanced to predefined length.
Make a note that the NULL handling is examined at first execution
(i.e. when input types altered) and for all subsequent executions
we don't read any values for this.
RETURN VALUE
none
*/
static void set_param_tiny(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 1)
return;
#endif
int8 value= (int8) **pos;
param->set_int(param->unsigned_flag ? (longlong) ((uint8) value) :
(longlong) value, 4);
*pos+= 1;
}
static void set_param_short(Item_param *param, uchar **pos, ulong len)
{
int16 value;
#ifndef EMBEDDED_LIBRARY
if (len < 2)
return;
value= sint2korr(*pos);
#else
shortget(value, *pos);
#endif
param->set_int(param->unsigned_flag ? (longlong) ((uint16) value) :
(longlong) value, 6);
*pos+= 2;
}
static void set_param_int32(Item_param *param, uchar **pos, ulong len)
{
int32 value;
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
value= sint4korr(*pos);
#else
longget(value, *pos);
#endif
param->set_int(param->unsigned_flag ? (longlong) ((uint32) value) :
(longlong) value, 11);
*pos+= 4;
}
static void set_param_int64(Item_param *param, uchar **pos, ulong len)
{
longlong value;
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
value= (longlong) sint8korr(*pos);
#else
longlongget(value, *pos);
#endif
param->set_int(value, 21);
*pos+= 8;
}
static void set_param_float(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 4)
return;
#endif
float data;
float4get(data,*pos);
param->set_double((double) data);
*pos+= 4;
}
static void set_param_double(Item_param *param, uchar **pos, ulong len)
{
#ifndef EMBEDDED_LIBRARY
if (len < 8)
return;
#endif
double data;
float8get(data,*pos);
param->set_double((double) data);
*pos+= 8;
}
#ifndef EMBEDDED_LIBRARY
/*
Read date/time/datetime parameter values from network (binary
protocol). See writing counterparts of these functions in
libmysql.c (store_param_{time,date,datetime}).
*/
static void set_param_time(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME tm;
ulong length= get_param_length(pos, len);
if (length >= 8)
{
uchar *to= *pos;
uint day;
tm.neg= (bool) to[0];
day= (uint) sint4korr(to+1);
tm.hour= (uint) to[5] + day * 24;
tm.minute= (uint) to[6];
tm.second= (uint) to[7];
tm.second_part= (length > 8) ? (ulong) sint4korr(to+8) : 0;
if (tm.hour > 838)
{
/* TODO: add warning 'Data truncated' here */
tm.hour= 838;
tm.minute= 59;
tm.second= 59;
}
tm.day= tm.year= tm.month= 0;
}
else
set_zero_time(&tm, MYSQL_TIMESTAMP_TIME);
param->set_time(&tm, MYSQL_TIMESTAMP_TIME,
MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
*pos+= length;
}
static void set_param_datetime(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME tm;
ulong length= get_param_length(pos, len);
if (length >= 4)
{
uchar *to= *pos;
tm.neg= 0;
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
if (length > 4)
{
tm.hour= (uint) to[4];
tm.minute= (uint) to[5];
tm.second= (uint) to[6];
}
else
tm.hour= tm.minute= tm.second= 0;
tm.second_part= (length > 7) ? (ulong) sint4korr(to+7) : 0;
}
else
set_zero_time(&tm, MYSQL_TIMESTAMP_DATETIME);
param->set_time(&tm, MYSQL_TIMESTAMP_DATETIME,
MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
*pos+= length;
}
static void set_param_date(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME tm;
ulong length= get_param_length(pos, len);
if (length >= 4)
{
uchar *to= *pos;
tm.year= (uint) sint2korr(to);
tm.month= (uint) to[2];
tm.day= (uint) to[3];
tm.hour= tm.minute= tm.second= 0;
tm.second_part= 0;
tm.neg= 0;
}
else
set_zero_time(&tm, MYSQL_TIMESTAMP_DATE);
param->set_time(&tm, MYSQL_TIMESTAMP_DATE,
MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
*pos+= length;
}
#else/*!EMBEDDED_LIBRARY*/
void set_param_time(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME tm= *((MYSQL_TIME*)*pos);
tm.hour+= tm.day * 24;
tm.day= tm.year= tm.month= 0;
if (tm.hour > 838)
{
/* TODO: add warning 'Data truncated' here */
tm.hour= 838;
tm.minute= 59;
tm.second= 59;
}
param->set_time(&tm, MYSQL_TIMESTAMP_TIME,
MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
void set_param_datetime(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME *to= (MYSQL_TIME*)*pos;
param->set_time(to, MYSQL_TIMESTAMP_DATETIME,
MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
void set_param_date(Item_param *param, uchar **pos, ulong len)
{
MYSQL_TIME *to= (MYSQL_TIME*)*pos;
param->set_time(to, MYSQL_TIMESTAMP_DATE,
MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
}
#endif /*!EMBEDDED_LIBRARY*/
static void set_param_str(Item_param *param, uchar **pos, ulong len)
{
ulong length= get_param_length(pos, len);
param->set_str((const char *)*pos, length);
*pos+= length;
}
#undef get_param_length
static void setup_one_conversion_function(THD *thd, Item_param *param,
uchar param_type)
{
switch (param_type) {
case MYSQL_TYPE_TINY:
param->set_param_func= set_param_tiny;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_SHORT:
param->set_param_func= set_param_short;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_LONG:
param->set_param_func= set_param_int32;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_LONGLONG:
param->set_param_func= set_param_int64;
param->item_type= Item::INT_ITEM;
param->item_result_type= INT_RESULT;
break;
case MYSQL_TYPE_FLOAT:
param->set_param_func= set_param_float;
param->item_type= Item::REAL_ITEM;
param->item_result_type= REAL_RESULT;
break;
case MYSQL_TYPE_DOUBLE:
param->set_param_func= set_param_double;
param->item_type= Item::REAL_ITEM;
param->item_result_type= REAL_RESULT;
break;
case MYSQL_TYPE_TIME:
param->set_param_func= set_param_time;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_DATE:
param->set_param_func= set_param_date;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_DATETIME:
case MYSQL_TYPE_TIMESTAMP:
param->set_param_func= set_param_datetime;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
case MYSQL_TYPE_TINY_BLOB:
case MYSQL_TYPE_MEDIUM_BLOB:
case MYSQL_TYPE_LONG_BLOB:
case MYSQL_TYPE_BLOB:
param->set_param_func= set_param_str;
param->value.cs_info.character_set_client= &my_charset_bin;
param->value.cs_info.final_character_set_of_str_value= &my_charset_bin;
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
break;
default:
/*
The client library ensures that we won't get any other typecodes
except typecodes above and typecodes for string types. Marking
label as 'default' lets us to handle malformed packets as well.
*/
{
CHARSET_INFO *fromcs= thd->variables.character_set_client;
CHARSET_INFO *tocs= thd->variables.collation_connection;
uint32 dummy_offset;
param->value.cs_info.character_set_client= fromcs;
/*
Setup source and destination character sets so that they
are different only if conversion is necessary: this will
make later checks easier.
*/
param->value.cs_info.final_character_set_of_str_value=
String::needs_conversion(0, fromcs, tocs, &dummy_offset) ?
tocs : fromcs;
param->set_param_func= set_param_str;
/*
Exact value of max_length is not known unless data is converted to
charset of connection, so we have to set it later.
*/
param->item_type= Item::STRING_ITEM;
param->item_result_type= STRING_RESULT;
}
}
param->param_type= (enum enum_field_types) param_type;
}
#ifndef EMBEDDED_LIBRARY
/*
Update the parameter markers by reading data from client packet
and if binary/update log is set, generate the valid query.
*/
static bool insert_params_withlog(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end,
String *query)
{
THD *thd= stmt->thd;
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
uint32 length= 0;
String str;
const String *res;
DBUG_ENTER("insert_params_withlog");
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (is_param_null(null_array, it - begin))
param->set_null();
else
{
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
}
}
res= param->query_val_str(&str);
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
DBUG_RETURN(0);
}
static bool insert_params(Prepared_statement *stmt, uchar *null_array,
uchar *read_pos, uchar *data_end,
String *expanded_query)
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
DBUG_ENTER("insert_params");
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (is_param_null(null_array, it - begin))
param->set_null();
else
{
if (read_pos >= data_end)
DBUG_RETURN(1);
param->set_param_func(param, &read_pos, data_end - read_pos);
}
}
if (param->convert_str_value(stmt->thd))
DBUG_RETURN(1); /* out of memory */
}
DBUG_RETURN(0);
}
static bool setup_conversion_functions(Prepared_statement *stmt,
uchar **data, uchar *data_end)
{
/* skip null bits */
uchar *read_pos= *data + (stmt->param_count+7) / 8;
DBUG_ENTER("setup_conversion_functions");
if (*read_pos++) //types supplied / first execute
{
/*
First execute or types altered by the client, setup the
conversion routines for all parameters (one time)
*/
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
THD *thd= stmt->thd;
for (; it < end; ++it)
{
ushort typecode;
const uint signed_bit= 1 << 15;
if (read_pos >= data_end)
DBUG_RETURN(1);
typecode= sint2korr(read_pos);
read_pos+= 2;
(**it).unsigned_flag= test(typecode & signed_bit);
setup_one_conversion_function(thd, *it, (uchar) (typecode & ~signed_bit));
}
}
*data= read_pos;
DBUG_RETURN(0);
}
#else
static bool emb_insert_params(Prepared_statement *stmt, String *expanded_query)
{
THD *thd= stmt->thd;
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= stmt->thd->client_params;
DBUG_ENTER("emb_insert_params");
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(thd, param, client_param->buffer_type);
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (*client_param->is_null)
param->set_null();
else
{
uchar *buff= (uchar*) client_param->buffer;
param->unsigned_flag= client_param->is_unsigned;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
}
}
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
}
DBUG_RETURN(0);
}
static bool emb_insert_params_withlog(Prepared_statement *stmt, String *query)
{
THD *thd= stmt->thd;
Item_param **it= stmt->param_array;
Item_param **end= it + stmt->param_count;
MYSQL_BIND *client_param= thd->client_params;
String str;
const String *res;
uint32 length= 0;
DBUG_ENTER("emb_insert_params_withlog");
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (; it < end; ++it, ++client_param)
{
Item_param *param= *it;
setup_one_conversion_function(thd, param, client_param->buffer_type);
if (param->state != Item_param::LONG_DATA_VALUE)
{
if (*client_param->is_null)
param->set_null();
else
{
uchar *buff= (uchar*)client_param->buffer;
param->unsigned_flag= client_param->is_unsigned;
param->set_param_func(param, &buff,
client_param->length ?
*client_param->length :
client_param->buffer_length);
}
}
res= param->query_val_str(&str);
if (param->convert_str_value(thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, *res))
DBUG_RETURN(1);
length+= res->length()-1;
}
DBUG_RETURN(0);
}
#endif /*!EMBEDDED_LIBRARY*/
/*
Set prepared statement parameters from user variables.
SYNOPSIS
insert_params_from_vars()
stmt Statement
varnames List of variables. Caller must ensure that number of variables
in the list is equal to number of statement parameters
query Ignored
*/
static bool insert_params_from_vars(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *query __attribute__((unused)))
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
user_var_entry *entry;
LEX_STRING *varname;
List_iterator<LEX_STRING> var_it(varnames);
DBUG_ENTER("insert_params_from_vars");
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
varname= var_it++;
entry= (user_var_entry*)hash_search(&stmt->thd->user_vars,
(byte*) varname->str,
varname->length);
if (param->set_from_user_var(stmt->thd, entry) ||
param->convert_str_value(stmt->thd))
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/*
Do the same as insert_params_from_vars but also construct query text for
binary log.
SYNOPSIS
insert_params_from_vars()
stmt Statement
varnames List of variables. Caller must ensure that number of variables
in the list is equal to number of statement parameters
query The query with parameter markers replaced with their values
*/
static bool insert_params_from_vars_with_log(Prepared_statement *stmt,
List<LEX_STRING>& varnames,
String *query)
{
Item_param **begin= stmt->param_array;
Item_param **end= begin + stmt->param_count;
user_var_entry *entry;
LEX_STRING *varname;
DBUG_ENTER("insert_params_from_vars");
List_iterator<LEX_STRING> var_it(varnames);
String buf;
const String *val;
uint32 length= 0;
if (query->copy(stmt->query, stmt->query_length, default_charset_info))
DBUG_RETURN(1);
for (Item_param **it= begin; it < end; ++it)
{
Item_param *param= *it;
varname= var_it++;
if (get_var_with_binlog(stmt->thd, *varname, &entry))
DBUG_RETURN(1);
if (param->set_from_user_var(stmt->thd, entry))
DBUG_RETURN(1);
/* Insert @'escaped-varname' instead of parameter in the query */
if (entry)
{
char *begin, *ptr;
buf.length(0);
if (buf.reserve(entry->name.length*2+3))
DBUG_RETURN(1);
begin= ptr= buf.c_ptr_quick();
*ptr++= '@';
*ptr++= '\'';
ptr+= escape_string_for_mysql(&my_charset_utf8_general_ci,
ptr, entry->name.str, entry->name.length);
*ptr++= '\'';
buf.length(ptr - begin);
val= &buf;
}
else
val= &my_null_string;
if (param->convert_str_value(stmt->thd))
DBUG_RETURN(1); /* out of memory */
if (query->replace(param->pos_in_query+length, 1, *val))
DBUG_RETURN(1);
length+= val->length()-1;
}
DBUG_RETURN(0);
}
/*
Validate INSERT statement:
SYNOPSIS
mysql_test_insert()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 ok
1 error, sent to the client
-1 error, not sent to client
*/
static int mysql_test_insert(Prepared_statement *stmt,
TABLE_LIST *table_list,
List<Item> &fields,
List<List_item> &values_list,
List<Item> &update_fields,
List<Item> &update_values,
enum_duplicates duplic)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
List_iterator_fast<List_item> its(values_list);
List_item *values;
int res= -1;
TABLE_LIST *insert_table_list=
(TABLE_LIST*) lex->select_lex.table_list.first;
DBUG_ENTER("mysql_test_insert");
if ((res= insert_precheck(thd, table_list)))
DBUG_RETURN(res);
/*
open temporary memory pool for temporary data allocated by derived
tables & preparation procedure
Note that this is done without locks (should not be needed as we will not
access any data here)
If we would use locks, then we have to ensure we are not using
TL_WRITE_DELAYED as having two such locks can cause table corruption.
*/
if (open_normal_and_derived_tables(thd, table_list))
{
DBUG_RETURN(-1);
}
if ((values= its++))
{
uint value_count;
ulong counter= 0;
table_list->table->insert_values=(byte *)1; // don't allocate insert_values
if ((res= mysql_prepare_insert(thd, table_list, insert_table_list,
insert_table_list,
table_list->table, fields, values,
update_fields, update_values, duplic)))
goto error;
value_count= values->elements;
its.rewind();
while ((values= its++))
{
counter++;
if (values->elements != value_count)
{
my_printf_error(ER_WRONG_VALUE_COUNT_ON_ROW,
ER(ER_WRONG_VALUE_COUNT_ON_ROW),
MYF(0), counter);
goto error;
}
if (setup_fields(thd, 0, insert_table_list, *values, 0, 0, 0))
goto error;
}
}
res= 0;
error:
lex->unit.cleanup();
table_list->table->insert_values=0;
DBUG_RETURN(res);
}
/*
Validate UPDATE statement
SYNOPSIS
mysql_test_update()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_update(Prepared_statement *stmt,
TABLE_LIST *table_list)
{
int res;
THD *thd= stmt->thd;
SELECT_LEX *select= &stmt->lex->select_lex;
DBUG_ENTER("mysql_test_update");
if ((res= update_precheck(thd, table_list)))
DBUG_RETURN(res);
if (open_and_lock_tables(thd, table_list))
res= -1;
else
{
TABLE_LIST *update_table_list= (TABLE_LIST *)select->table_list.first;
if (!(res= mysql_prepare_update(thd, table_list,
update_table_list,
&select->where,
select->order_list.elements,
(ORDER *) select->order_list.first)))
{
if (setup_fields(thd, 0, update_table_list,
select->item_list, 1, 0, 0) ||
setup_fields(thd, 0, update_table_list,
stmt->lex->value_list, 0, 0, 0))
res= -1;
}
stmt->lex->unit.cleanup();
}
/* TODO: here we should send types of placeholders to the client. */
DBUG_RETURN(res);
}
/*
Validate DELETE statement
SYNOPSIS
mysql_test_delete()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_delete(Prepared_statement *stmt,
TABLE_LIST *table_list)
{
int res;
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
DBUG_ENTER("mysql_test_delete");
if ((res= delete_precheck(thd, table_list)))
DBUG_RETURN(res);
if (open_and_lock_tables(thd, table_list))
res= -1;
else
{
res= mysql_prepare_delete(thd, table_list, &lex->select_lex.where);
lex->unit.cleanup();
}
/* TODO: here we should send types of placeholders to the client. */
DBUG_RETURN(res);
}
/*
Validate SELECT statement.
In case of success, if this query is not EXPLAIN, send column list info
back to client.
SYNOPSIS
mysql_test_select()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_select(Prepared_statement *stmt,
TABLE_LIST *tables, bool text_protocol)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX_UNIT *unit= &lex->unit;
int result= 1;
DBUG_ENTER("mysql_test_select");
#ifndef NO_EMBEDDED_ACCESS_CHECKS
ulong privilege= lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL;
if (tables)
{
if (check_table_access(thd, privilege, tables,0))
DBUG_RETURN(1);
}
else if (check_access(thd, privilege, any_db,0,0,0))
DBUG_RETURN(1);
#endif
if (!lex->result && !(lex->result= new (stmt->mem_root) select_send))
{
send_error(thd);
goto err;
}
if (open_and_lock_tables(thd, tables))
{
send_error(thd);
goto err;
}
thd->used_tables= 0; // Updated by setup_fields
// JOIN::prepare calls
if (unit->prepare(thd, 0, 0, ""))
{
send_error(thd);
goto err_prep;
}
if (!text_protocol)
{
if (lex->describe)
{
if (send_prep_stmt(stmt, 0) || thd->protocol->flush())
goto err_prep;
}
else
{
/* Make copy of item list, as change_columns may change it */
List<Item> fields(lex->select_lex.item_list);
/* Change columns if a procedure like analyse() */
if (unit->last_procedure &&
unit->last_procedure->change_columns(fields))
goto err_prep;
/*
We can use lex->result as it should've been
prepared in unit->prepare call above.
*/
if (send_prep_stmt(stmt, lex->result->field_count(fields)) ||
lex->result->send_fields(fields, 0) ||
thd->protocol->flush())
goto err_prep;
}
}
result= 0; // ok
err_prep:
unit->cleanup();
err:
DBUG_RETURN(result);
}
/*
Validate and prepare for execution DO statement expressions
SYNOPSIS
mysql_test_do_fields()
stmt prepared statemen handler
tables list of tables queries
values list of expressions
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_do_fields(Prepared_statement *stmt,
TABLE_LIST *tables,
List<Item> *values)
{
DBUG_ENTER("mysql_test_do_fields");
THD *thd= stmt->thd;
int res= 0;
if (tables && (res= check_table_access(thd, SELECT_ACL, tables, 0)))
DBUG_RETURN(res);
if (tables && (res= open_and_lock_tables(thd, tables)))
{
DBUG_RETURN(res);
}
res= setup_fields(thd, 0, 0, *values, 0, 0, 0);
stmt->lex->unit.cleanup();
if (res)
DBUG_RETURN(-1);
DBUG_RETURN(0);
}
/*
Validate and prepare for execution SET statement expressions
SYNOPSIS
mysql_test_set_fields()
stmt prepared statemen handler
tables list of tables queries
values list of expressions
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_set_fields(Prepared_statement *stmt,
TABLE_LIST *tables,
List<set_var_base> *var_list)
{
DBUG_ENTER("mysql_test_set_fields");
List_iterator_fast<set_var_base> it(*var_list);
THD *thd= stmt->thd;
set_var_base *var;
int res= 0;
if (tables && (res= check_table_access(thd, SELECT_ACL, tables, 0)))
DBUG_RETURN(res);
if (tables && (res= open_and_lock_tables(thd, tables)))
goto error;
while ((var= it++))
{
if (var->light_check(thd))
{
stmt->lex->unit.cleanup();
res= -1;
goto error;
}
}
error:
stmt->lex->unit.cleanup();
DBUG_RETURN(res);
}
/*
Check internal SELECT of the prepared command
SYNOPSIS
select_like_statement_test()
stmt - prepared table handler
tables - global list of tables
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int select_like_statement_test(Prepared_statement *stmt,
TABLE_LIST *tables)
{
DBUG_ENTER("select_like_statement_test");
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
int res= 0;
if (tables && (res= open_and_lock_tables(thd, tables)))
goto end;
thd->used_tables= 0; // Updated by setup_fields
// JOIN::prepare calls
if (lex->unit.prepare(thd, 0, 0, ""))
{
res= thd->net.report_error ? -1 : 1;
}
end:
lex->unit.cleanup();
DBUG_RETURN(res);
}
/*
Validate and prepare for execution CREATE TABLE statement
SYNOPSIS
mysql_test_create_table()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_create_table(Prepared_statement *stmt,
TABLE_LIST *tables)
{
DBUG_ENTER("mysql_test_create_table");
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *select_lex= &lex->select_lex;
int res= 0;
/* Skip first table, which is the table we are creating */
TABLE_LIST *create_table, *create_table_local;
tables= lex->unlink_first_table(tables, &create_table,
&create_table_local);
if (!(res= create_table_precheck(thd, tables, create_table)) &&
select_lex->item_list.elements)
{
select_lex->resolve_mode= SELECT_LEX::SELECT_MODE;
res= select_like_statement_test(stmt, tables);
select_lex->resolve_mode= SELECT_LEX::NOMATTER_MODE;
}
/* put tables back for PS rexecuting */
tables= lex->link_first_table_back(tables, create_table,
create_table_local);
DBUG_RETURN(res);
}
/*
Validate and prepare for execution multi update statement
SYNOPSIS
mysql_test_multiupdate()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_multiupdate(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
if ((res= multi_update_precheck(stmt->thd, tables)))
return res;
return select_like_statement_test(stmt, tables);
}
/*
Validate and prepare for execution multi delete statement
SYNOPSIS
mysql_test_multidelete()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_multidelete(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
stmt->thd->lex->current_select= &stmt->thd->lex->select_lex;
if (add_item_to_list(stmt->thd, new Item_null()))
return -1;
uint fake_counter;
if ((res= multi_delete_precheck(stmt->thd, tables, &fake_counter)))
return res;
return select_like_statement_test(stmt, tables);
}
/*
Validate and prepare for execution INSERT ... SELECT statement
SYNOPSIS
mysql_test_insert_select()
stmt prepared statemen handler
tables list of tables queries
RETURN VALUE
0 success
1 error, sent to client
-1 error, not sent to client
*/
static int mysql_test_insert_select(Prepared_statement *stmt,
TABLE_LIST *tables)
{
int res;
LEX *lex= stmt->lex;
if ((res= insert_precheck(stmt->thd, tables)))
return res;
TABLE_LIST *first_local_table=
(TABLE_LIST *)lex->select_lex.table_list.first;
/* Skip first table, which is the table we are inserting in */
lex->select_lex.table_list.first= (byte*) first_local_table->next;
/*
insert/replace from SELECT give its SELECT_LEX for SELECT,
and item_list belong to SELECT
*/
lex->select_lex.resolve_mode= SELECT_LEX::SELECT_MODE;
res= select_like_statement_test(stmt, tables);
/* revert changes*/
lex->select_lex.table_list.first= (byte*) first_local_table;
lex->select_lex.resolve_mode= SELECT_LEX::INSERT_MODE;
return res;
}
/*
Send the prepare query results back to client
SYNOPSIS
send_prepare_results()
stmt prepared statement
RETURN VALUE
0 success
1 error, sent to client
*/
static int send_prepare_results(Prepared_statement *stmt, bool text_protocol)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *select_lex= &lex->select_lex;
TABLE_LIST *tables=(TABLE_LIST*) select_lex->table_list.first;
enum enum_sql_command sql_command= lex->sql_command;
int res= 0;
DBUG_ENTER("send_prepare_results");
DBUG_PRINT("enter",("command: %d, param_count: %ld",
sql_command, stmt->param_count));
if ((&lex->select_lex != lex->all_selects_list ||
lex->time_zone_tables_used) &&
lex->unit.create_total_list(thd, lex, &tables))
DBUG_RETURN(1);
switch (sql_command) {
case SQLCOM_REPLACE:
case SQLCOM_INSERT:
res= mysql_test_insert(stmt, tables, lex->field_list,
lex->many_values,
select_lex->item_list, lex->value_list,
lex->duplicates);
break;
case SQLCOM_UPDATE:
res= mysql_test_update(stmt, tables);
break;
case SQLCOM_DELETE:
res= mysql_test_delete(stmt, tables);
break;
case SQLCOM_SELECT:
if ((res= mysql_test_select(stmt, tables, text_protocol)))
goto error;
/* Statement and field info has already been sent */
DBUG_RETURN(0);
case SQLCOM_CREATE_TABLE:
res= mysql_test_create_table(stmt, tables);
break;
case SQLCOM_DO:
res= mysql_test_do_fields(stmt, tables, lex->insert_list);
break;
case SQLCOM_SET_OPTION:
res= mysql_test_set_fields(stmt, tables, &lex->var_list);
break;
case SQLCOM_DELETE_MULTI:
res= mysql_test_multidelete(stmt, tables);
break;
case SQLCOM_UPDATE_MULTI:
res= mysql_test_multiupdate(stmt, tables);
break;
case SQLCOM_INSERT_SELECT:
case SQLCOM_REPLACE_SELECT:
res= mysql_test_insert_select(stmt, tables);
break;
case SQLCOM_SHOW_DATABASES:
case SQLCOM_SHOW_PROCESSLIST:
case SQLCOM_SHOW_STORAGE_ENGINES:
case SQLCOM_SHOW_PRIVILEGES:
case SQLCOM_SHOW_COLUMN_TYPES:
case SQLCOM_SHOW_STATUS:
case SQLCOM_SHOW_VARIABLES:
case SQLCOM_SHOW_LOGS:
case SQLCOM_SHOW_TABLES:
case SQLCOM_SHOW_OPEN_TABLES:
case SQLCOM_SHOW_CHARSETS:
case SQLCOM_SHOW_COLLATIONS:
case SQLCOM_SHOW_FIELDS:
case SQLCOM_SHOW_KEYS:
case SQLCOM_SHOW_CREATE_DB:
case SQLCOM_SHOW_GRANTS:
case SQLCOM_DROP_TABLE:
case SQLCOM_RENAME_TABLE:
break;
default:
/*
All other is not supported yet
*/
res= -1;
my_error(ER_UNSUPPORTED_PS, MYF(0));
goto error;
}
if (res == 0)
DBUG_RETURN(text_protocol? 0 : (send_prep_stmt(stmt, 0) ||
thd->protocol->flush()));
error:
if (res < 0)
send_error(thd, thd->killed ? ER_SERVER_SHUTDOWN : 0);
DBUG_RETURN(1);
}
/*
Initialize array of parameters in statement from LEX.
(We need to have quick access to items by number in mysql_stmt_get_longdata).
This is to avoid using malloc/realloc in the parser.
*/
static bool init_param_array(Prepared_statement *stmt)
{
LEX *lex= stmt->lex;
THD *thd= stmt->thd;
if ((stmt->param_count= lex->param_list.elements))
{
if (stmt->param_count > (uint) UINT_MAX16)
{
/* Error code to be defined in 5.0 */
send_error(thd, ER_UNKNOWN_ERROR,
"Prepared statement contains too many placeholders.");
return 1;
}
Item_param **to;
List_iterator<Item_param> param_iterator(lex->param_list);
/* Use thd->mem_root as it points at statement mem_root */
stmt->param_array= (Item_param **)
alloc_root(stmt->thd->mem_root,
sizeof(Item_param*) * stmt->param_count);
if (!stmt->param_array)
{
send_error(thd, ER_OUT_OF_RESOURCES);
return 1;
}
for (to= stmt->param_array;
to < stmt->param_array + stmt->param_count;
++to)
{
*to= param_iterator++;
}
}
return 0;
}
/*
Given a query string with parameter markers, create a Prepared Statement
from it and send PS info back to the client.
SYNOPSIS
mysql_stmt_prepare()
packet query to be prepared
packet_length query string length, including ignored trailing NULL or
quote char.
name NULL or statement name. For unnamed statements binary PS
protocol is used, for named statements text protocol is
used.
RETURN
0 OK, statement prepared successfully
other Error
NOTES
This function parses the query and sends the total number of parameters
and resultset metadata information back to client (if any), without
executing the query i.e. without any log/disk writes. This allows the
queries to be re-executed without re-parsing during execute.
If parameter markers are found in the query, then store the information
using Item_param along with maintaining a list in lex->param_array, so
that a fast and direct retrieval can be made without going through all
field items.
*/
int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
LEX_STRING *name)
{
LEX *lex;
Prepared_statement *stmt= new Prepared_statement(thd);
int error;
DBUG_ENTER("mysql_stmt_prepare");
DBUG_PRINT("prep_query", ("%s", packet));
/*
If this is an SQLCOM_PREPARE, we also increase Com_prepare_sql.
However, it seems handy if com_stmt_prepare is increased always,
no matter what kind of prepare is processed.
*/
statistic_increment(com_stmt_prepare, &LOCK_status);
if (stmt == 0)
{
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
if (name)
{
stmt->name.length= name->length;
if (!(stmt->name.str= memdup_root(stmt->mem_root, (char*)name->str,
name->length)))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
}
if (thd->stmt_map.insert(stmt))
{
delete stmt;
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
thd->set_n_backup_statement(stmt, &thd->stmt_backup);
thd->set_n_backup_item_arena(stmt, &thd->stmt_backup);
if (alloc_query(thd, packet, packet_length))
{
thd->restore_backup_statement(stmt, &thd->stmt_backup);
thd->restore_backup_item_arena(stmt, &thd->stmt_backup);
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
send_error(thd, ER_OUT_OF_RESOURCES);
DBUG_RETURN(1);
}
mysql_log.write(thd, thd->command, "[%lu] %s", stmt->id, packet);
thd->current_arena= stmt;
mysql_init_query(thd, (uchar *) thd->query, thd->query_length);
/* Reset warnings from previous command */
mysql_reset_errors(thd);
lex= thd->lex;
lex->safe_to_cache_query= 0;
error= yyparse((void *)thd) || thd->is_fatal_error ||
thd->net.report_error || init_param_array(stmt);
/*
While doing context analysis of the query (in send_prepare_results) we
allocate a lot of additional memory: for open tables, JOINs, derived
tables, etc. Let's save a snapshot of current parse tree to the
statement and restore original THD. In cases when some tree
transformation can be reused on execute, we set again thd->mem_root from
stmt->mem_root (see setup_wild for one place where we do that).
*/
thd->restore_backup_item_arena(stmt, &thd->stmt_backup);
if (!error)
error= send_prepare_results(stmt, test(name));
/* restore to WAIT_PRIOR: QUERY_PRIOR is set inside alloc_query */
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),WAIT_PRIOR);
lex_end(lex);
thd->restore_backup_statement(stmt, &thd->stmt_backup);
cleanup_items(stmt->free_list);
close_thread_tables(thd);
free_items(thd->free_list);
thd->rollback_item_tree_changes();
thd->free_list= 0;
thd->current_arena= thd;
if (error)
{
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
stmt= NULL;
if (thd->net.report_error)
send_error(thd);
/* otherwise the error is sent inside yyparse/send_prepare_results */
}
else
{
stmt->setup_set_params();
SELECT_LEX *sl= stmt->lex->all_selects_list;
for (; sl; sl= sl->next_select_in_list())
{
/*
Save WHERE clause pointers, because they may be changed
during query optimisation.
*/
sl->prep_where= sl->where;
/*
Switch off a temporary flag that prevents evaluation of
subqueries in statement prepare.
*/
sl->uncacheable&= ~UNCACHEABLE_PREPARE;
}
stmt->state= Item_arena::PREPARED;
}
DBUG_RETURN(!stmt);
}
/* Reinit statement before execution */
static void reset_stmt_for_execute(Prepared_statement *stmt)
{
THD *thd= stmt->thd;
LEX *lex= stmt->lex;
SELECT_LEX *sl= lex->all_selects_list;
for (; sl; sl= sl->next_select_in_list())
{
/* remove option which was put by mysql_explain_union() */
sl->options&= ~SELECT_DESCRIBE;
/*
Copy WHERE clause pointers to avoid damaging they by optimisation
*/
if (sl->prep_where)
{
sl->where= sl->prep_where->copy_andor_structure(thd);
sl->where->cleanup();
}
DBUG_ASSERT(sl->join == 0);
ORDER *order;
/* Fix GROUP list */
for (order= (ORDER *)sl->group_list.first; order; order= order->next)
order->item= &order->item_ptr;
/* Fix ORDER list */
for (order= (ORDER *)sl->order_list.first; order; order= order->next)
order->item= &order->item_ptr;
/*
TODO: When the new table structure is ready, then have a status bit
to indicate the table is altered, and re-do the setup_*
and open the tables back.
*/
for (TABLE_LIST *tables= (TABLE_LIST*) sl->table_list.first;
tables;
tables= tables->next)
{
/*
Reset old pointers to TABLEs: they are not valid since the tables
were closed in the end of previous prepare or execute call.
*/
tables->table= 0;
tables->table_list= 0;
}
{
SELECT_LEX_UNIT *unit= sl->master_unit();
unit->unclean();
unit->types.empty();
/* for derived tables & PS (which can't be reset by Item_subquery) */
unit->reinit_exec_mechanism();
}
}
lex->current_select= &lex->select_lex;
if (lex->result)
lex->result->cleanup();
}
/*
Clears parameters from data left from previous execution or long data
SYNOPSIS
reset_stmt_params()
stmt - prepared statement for which parameters should be reset
*/
static void reset_stmt_params(Prepared_statement *stmt)
{
Item_param **item= stmt->param_array;
Item_param **end= item + stmt->param_count;
for (;item < end ; ++item)
(**item).reset();
}
/*
Executes previously prepared query.
If there is any parameters, then replace markers with the data supplied
from client, and then execute the query.
SYNOPSIS
mysql_stmt_execute()
thd Current thread
packet Query string
packet_length Query string length, including terminator character.
*/
void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
{
ulong stmt_id= uint4korr(packet);
/*
Query text for binary log, or empty string if the query is not put into
binary log.
*/
String expanded_query;
#ifndef EMBEDDED_LIBRARY
uchar *packet_end= (uchar *) packet + packet_length - 1;
#endif
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_execute");
packet+= 9; /* stmt_id + 5 bytes of flags */
statistic_increment(com_stmt_execute, &LOCK_status);
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_execute",
SEND_ERROR)))
DBUG_VOID_RETURN;
DBUG_PRINT("exec_query:", ("%s", stmt->query));
/* Check if we got an error when sending long data */
if (stmt->state == Item_arena::ERROR)
{
send_error(thd, stmt->last_errno, stmt->last_error);
DBUG_VOID_RETURN;
}
DBUG_ASSERT(thd->free_list == NULL);
mysql_reset_thd_for_next_command(thd);
#ifndef EMBEDDED_LIBRARY
if (stmt->param_count)
{
uchar *null_array= (uchar *) packet;
if (setup_conversion_functions(stmt, (uchar **) &packet, packet_end) ||
stmt->set_params(stmt, null_array, (uchar *) packet, packet_end,
&expanded_query))
goto set_params_data_err;
}
#else
/*
In embedded library we re-install conversion routines each time
we set params, and also we don't need to parse packet.
So we do it in one function.
*/
if (stmt->param_count && stmt->set_params_data(stmt, &expanded_query))
goto set_params_data_err;
#endif
thd->protocol= &thd->protocol_prep; // Switch to binary protocol
execute_stmt(thd, stmt, &expanded_query, TRUE);
thd->protocol= &thd->protocol_simple; // Use normal protocol
DBUG_VOID_RETURN;
set_params_data_err:
reset_stmt_params(stmt);
my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_execute");
send_error(thd);
DBUG_VOID_RETURN;
}
/*
Execute prepared statement using parameter values from
lex->prepared_stmt_params and send result to the client using text protocol.
*/
void mysql_sql_stmt_execute(THD *thd, LEX_STRING *stmt_name)
{
Prepared_statement *stmt;
/*
Query text for binary log, or empty string if the query is not put into
binary log.
*/
String expanded_query;
DBUG_ENTER("mysql_sql_stmt_execute");
/* See comment for statistics_increment in mysql_stmt_prepare */
statistic_increment(com_stmt_execute, &LOCK_status);
if (!(stmt= (Prepared_statement*)thd->stmt_map.find_by_name(stmt_name)))
{
my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), stmt_name->length,
stmt_name->str, "EXECUTE");
send_error(thd);
DBUG_VOID_RETURN;
}
if (stmt->param_count != thd->lex->prepared_stmt_params.elements)
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE");
send_error(thd);
DBUG_VOID_RETURN;
}
DBUG_ASSERT(thd->free_list == NULL);
/* Must go before setting variables, as it clears thd->user_var_events */
mysql_reset_thd_for_next_command(thd);
thd->set_n_backup_statement(stmt, &thd->stmt_backup);
if (stmt->set_params_from_vars(stmt,
thd->stmt_backup.lex->prepared_stmt_params,
&expanded_query))
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE");
send_error(thd);
}
thd->command= COM_EXECUTE; /* For nice messages in general log */
execute_stmt(thd, stmt, &expanded_query, FALSE);
DBUG_VOID_RETURN;
}
/*
Execute prepared statement.
SYNOPSIS
execute_stmt()
thd Current thread
stmt Statement to execute
expanded_query If binary log is enabled, query string with parameter
placeholders replaced with actual values. Otherwise empty
string.
NOTES
Caller must set parameter values and thd::protocol.
thd->free_list is assumed to be garbage.
*/
static void execute_stmt(THD *thd, Prepared_statement *stmt,
String *expanded_query, bool set_context)
{
DBUG_ENTER("execute_stmt");
if (set_context)
thd->set_n_backup_statement(stmt, &thd->stmt_backup);
reset_stmt_for_execute(stmt);
if (expanded_query->length() &&
alloc_query(thd, (char *)expanded_query->ptr(),
expanded_query->length()+1))
{
my_error(ER_OUTOFMEMORY, 0, expanded_query->length());
DBUG_VOID_RETURN;
}
mysql_log.write(thd, thd->command, "[%lu] %s", stmt->id, thd->query);
/*
At first execution of prepared statement we will perform logical
transformations of the query tree (i.e. negations elimination).
This should be done permanently on the parse tree of this statement.
*/
thd->current_arena= stmt;
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),QUERY_PRIOR);
mysql_execute_command(thd);
thd->lex->unit.cleanup();
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(), WAIT_PRIOR);
/*
'start_time' is set in dispatch_command, but THD::query will
be freed when we return from this function. So let's log the slow
query here.
*/
log_slow_statement(thd);
/* Prevent from second logging in the end of dispatch_command */
thd->enable_slow_log= FALSE;
/* Free Items that were created during this execution of the PS. */
free_items(thd->free_list);
thd->free_list= 0;
if (stmt->state == Item_arena::PREPARED)
stmt->state= Item_arena::EXECUTED;
thd->current_arena= thd;
cleanup_items(stmt->free_list);
thd->rollback_item_tree_changes();
reset_stmt_params(stmt);
close_thread_tables(thd); // to close derived tables
thd->set_statement(&thd->stmt_backup);
DBUG_VOID_RETURN;
}
/*
Reset a prepared statement in case there was a recoverable error.
SYNOPSIS
mysql_stmt_reset()
thd Thread handle
packet Packet with stmt id
DESCRIPTION
This function resets statement to the state it was right after prepare.
It can be used to:
- clear an error happened during mysql_stmt_send_long_data
- cancel long data stream for all placeholders without
having to call mysql_stmt_execute.
Sends 'OK' packet in case of success (statement was reset)
or 'ERROR' packet (unrecoverable error/statement not found/etc).
*/
void mysql_stmt_reset(THD *thd, char *packet)
{
/* There is always space for 4 bytes in buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_reset");
statistic_increment(com_stmt_reset, &LOCK_status);
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_reset",
SEND_ERROR)))
DBUG_VOID_RETURN;
stmt->state= Item_arena::PREPARED;
/*
Clear parameters from data which could be set by
mysql_stmt_send_long_data() call.
*/
reset_stmt_params(stmt);
mysql_reset_thd_for_next_command(thd);
send_ok(thd);
DBUG_VOID_RETURN;
}
/*
Delete a prepared statement from memory.
Note: we don't send any reply to that command.
*/
void mysql_stmt_free(THD *thd, char *packet)
{
/* There is always space for 4 bytes in packet buffer */
ulong stmt_id= uint4korr(packet);
Prepared_statement *stmt;
DBUG_ENTER("mysql_stmt_free");
statistic_increment(com_stmt_close, &LOCK_status);
if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_close",
DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
/* Statement map deletes statement on erase */
thd->stmt_map.erase(stmt);
DBUG_VOID_RETURN;
}
/*
Long data in pieces from client
SYNOPSIS
mysql_stmt_get_longdata()
thd Thread handle
pos String to append
packet_length Length of string
DESCRIPTION
Get a part of a long data.
To make the protocol efficient, we are not sending any return packages
here.
If something goes wrong, then we will send the error on 'execute'
We assume that the client takes care of checking that all parts are sent
to the server. (No checking that we get a 'end of column' in the server)
*/
void mysql_stmt_get_longdata(THD *thd, char *packet, ulong packet_length)
{
ulong stmt_id;
uint param_number;
Prepared_statement *stmt;
Item_param *param;
char *packet_end= packet + packet_length - 1;
DBUG_ENTER("mysql_stmt_get_longdata");
statistic_increment(com_stmt_send_long_data, &LOCK_status);
#ifndef EMBEDDED_LIBRARY
/* Minimal size of long data packet is 6 bytes */
if ((ulong) (packet_end - packet) < MYSQL_LONG_DATA_HEADER)
{
my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_send_long_data");
DBUG_VOID_RETURN;
}
#endif
stmt_id= uint4korr(packet);
packet+= 4;
if (!(stmt=find_prepared_statement(thd, stmt_id, "mysql_stmt_send_long_data",
DONT_SEND_ERROR)))
DBUG_VOID_RETURN;
param_number= uint2korr(packet);
packet+= 2;
#ifndef EMBEDDED_LIBRARY
if (param_number >= stmt->param_count)
{
/* Error will be sent in execute call */
stmt->state= Item_arena::ERROR;
stmt->last_errno= ER_WRONG_ARGUMENTS;
sprintf(stmt->last_error, ER(ER_WRONG_ARGUMENTS),
"mysql_stmt_send_long_data");
DBUG_VOID_RETURN;
}
#endif
param= stmt->param_array[param_number];
#ifndef EMBEDDED_LIBRARY
if (param->set_longdata(packet, (ulong) (packet_end - packet)))
#else
if (param->set_longdata(thd->extra_data, thd->extra_length))
#endif
{
stmt->state= Item_arena::ERROR;
stmt->last_errno= ER_OUTOFMEMORY;
sprintf(stmt->last_error, ER(ER_OUTOFMEMORY), 0);
}
DBUG_VOID_RETURN;
}
Prepared_statement::Prepared_statement(THD *thd_arg)
:Statement(thd_arg),
thd(thd_arg),
param_array(0),
param_count(0),
last_errno(0)
{
*last_error= '\0';
}
void Prepared_statement::setup_set_params()
{
/* Setup binary logging */
if (mysql_bin_log.is_open() && is_update_query(lex->sql_command) ||
mysql_log.is_open() || mysql_slow_log.is_open())
{
set_params_from_vars= insert_params_from_vars_with_log;
#ifndef EMBEDDED_LIBRARY
set_params= insert_params_withlog;
#else
set_params_data= emb_insert_params_withlog;
#endif
}
else
{
set_params_from_vars= insert_params_from_vars;
#ifndef EMBEDDED_LIBRARY
set_params= insert_params;
#else
set_params_data= emb_insert_params;
#endif
}
}
Prepared_statement::~Prepared_statement()
{
free_items(free_list);
delete lex->result;
}
Item_arena::Type Prepared_statement::type() const
{
return PREPARED_STATEMENT;
}
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