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mariadb/sql/sql_view.cc
Gleb Shchepa fa430818c3 manual merge 5.0-bugteam --> 5.1-bugteam (bug 40021) 
sql_view.cc: required_view_parameters has been decreased by 2 
(not by 1) because its value was incorrect: 16 instead of 15
(minor performance issue).
2008-11-14 21:37:27 +04:00

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/* Copyright (C) 2004 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; version 2 of the License.
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
*/
#define MYSQL_LEX 1
#include "mysql_priv.h"
#include "sql_select.h"
#include "parse_file.h"
#include "sp.h"
#include "sp_head.h"
#include "sp_cache.h"
#define MD5_BUFF_LENGTH 33
const LEX_STRING view_type= { C_STRING_WITH_LEN("VIEW") };
static int mysql_register_view(THD *thd, TABLE_LIST *view,
enum_view_create_mode mode);
const char *updatable_views_with_limit_names[]= { "NO", "YES", NullS };
TYPELIB updatable_views_with_limit_typelib=
{
array_elements(updatable_views_with_limit_names)-1, "",
updatable_views_with_limit_names,
0
};
/*
Make a unique name for an anonymous view column
SYNOPSIS
target reference to the item for which a new name has to be made
item_list list of items within which we should check uniqueness of
the created name
last_element the last element of the list above
NOTE
Unique names are generated by adding 'My_exp_' to the old name of the
column. In case the name that was created this way already exists, we
add a numeric postfix to its end (i.e. "1") and increase the number
until the name becomes unique. If the generated name is longer than
NAME_LEN, it is truncated.
*/
static void make_unique_view_field_name(Item *target,
List<Item> &item_list,
Item *last_element)
{
char *name= (target->orig_name ?
target->orig_name :
target->name);
uint name_len, attempt;
char buff[NAME_LEN+1];
List_iterator_fast<Item> itc(item_list);
for (attempt= 0;; attempt++)
{
Item *check;
bool ok= TRUE;
if (attempt)
name_len= my_snprintf(buff, NAME_LEN, "My_exp_%d_%s", attempt, name);
else
name_len= my_snprintf(buff, NAME_LEN, "My_exp_%s", name);
do
{
check= itc++;
if (check != target &&
my_strcasecmp(system_charset_info, buff, check->name) == 0)
{
ok= FALSE;
break;
}
} while (check != last_element);
if (ok)
break;
itc.rewind();
}
target->orig_name= target->name;
target->set_name(buff, name_len, system_charset_info);
}
/*
Check if items with same names are present in list and possibly
generate unique names for them.
SYNOPSIS
item_list list of Items which should be checked for duplicates
gen_unique_view_name flag: generate unique name or return with error when
duplicate names are found.
DESCRIPTION
This function is used on view creation and preparation of derived tables.
It checks item_list for items with duplicate names. If it founds two
items with same name and conversion to unique names isn't allowed, or
names for both items are set by user - function fails.
Otherwise it generates unique name for one item with autogenerated name
using make_unique_view_field_name()
RETURN VALUE
FALSE no duplicate names found, or they are converted to unique ones
TRUE duplicate names are found and they can't be converted or conversion
isn't allowed
*/
bool check_duplicate_names(List<Item> &item_list, bool gen_unique_view_name)
{
Item *item;
List_iterator_fast<Item> it(item_list);
List_iterator_fast<Item> itc(item_list);
DBUG_ENTER("check_duplicate_names");
while ((item= it++))
{
Item *check;
/* treat underlying fields like set by user names */
if (item->real_item()->type() == Item::FIELD_ITEM)
item->is_autogenerated_name= FALSE;
itc.rewind();
while ((check= itc++) && check != item)
{
if (my_strcasecmp(system_charset_info, item->name, check->name) == 0)
{
if (!gen_unique_view_name)
goto err;
if (item->is_autogenerated_name)
make_unique_view_field_name(item, item_list, item);
else if (check->is_autogenerated_name)
make_unique_view_field_name(check, item_list, item);
else
goto err;
}
}
}
DBUG_RETURN(FALSE);
err:
my_error(ER_DUP_FIELDNAME, MYF(0), item->name);
DBUG_RETURN(TRUE);
}
/*
Fill defined view parts
SYNOPSIS
fill_defined_view_parts()
thd current thread.
view view to operate on
DESCRIPTION
This function will initialize the parts of the view
definition that are not specified in ALTER VIEW
to their values from CREATE VIEW.
The view must be opened to get its definition.
We use a copy of the view when opening because we want
to preserve the original view instance.
RETURN VALUE
TRUE can't open table
FALSE success
*/
static bool
fill_defined_view_parts (THD *thd, TABLE_LIST *view)
{
LEX *lex= thd->lex;
bool not_used;
TABLE_LIST decoy;
memcpy (&decoy, view, sizeof (TABLE_LIST));
/*
Let's reset decoy.view before calling open_table(): when we start
supporting ALTER VIEW in PS/SP that may save us from a crash.
*/
decoy.view= NULL;
/*
open_table() will return NULL if 'decoy' is idenitifying a view *and*
there is no TABLE object for that view in the table cache. However,
decoy.view will be set to 1.
If there is a TABLE-instance for the oject identified by 'decoy',
open_table() will return that instance no matter if it is a table or
a view.
Thus, there is no need to check for the return value of open_table(),
since the return value itself does not mean anything.
*/
open_table(thd, &decoy, thd->mem_root, &not_used, OPEN_VIEW_NO_PARSE);
if (!decoy.view)
{
/* It's a table. */
my_error(ER_WRONG_OBJECT, MYF(0), view->db, view->table_name, "VIEW");
return TRUE;
}
if (!lex->definer)
{
view->definer.host= decoy.definer.host;
view->definer.user= decoy.definer.user;
lex->definer= &view->definer;
}
if (lex->create_view_algorithm == VIEW_ALGORITHM_UNDEFINED)
lex->create_view_algorithm= (uint8) decoy.algorithm;
if (lex->create_view_suid == VIEW_SUID_DEFAULT)
lex->create_view_suid= decoy.view_suid ?
VIEW_SUID_DEFINER : VIEW_SUID_INVOKER;
return FALSE;
}
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/**
@brief CREATE VIEW privileges pre-check.
@param thd thread handler
@param tables tables used in the view
@param views views to create
@param mode VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE
@retval FALSE Operation was a success.
@retval TRUE An error occured.
*/
bool create_view_precheck(THD *thd, TABLE_LIST *tables, TABLE_LIST *view,
enum_view_create_mode mode)
{
LEX *lex= thd->lex;
/* first table in list is target VIEW name => cut off it */
TABLE_LIST *tbl;
SELECT_LEX *select_lex= &lex->select_lex;
SELECT_LEX *sl;
bool res= TRUE;
DBUG_ENTER("create_view_precheck");
/*
Privilege check for view creation:
- user has CREATE VIEW privilege on view table
- user has DROP privilege in case of ALTER VIEW or CREATE OR REPLACE
VIEW
- user has some (SELECT/UPDATE/INSERT/DELETE) privileges on columns of
underlying tables used on top of SELECT list (because it can be
(theoretically) updated, so it is enough to have UPDATE privilege on
them, for example)
- user has SELECT privilege on columns used in expressions of VIEW select
- for columns of underly tables used on top of SELECT list also will be
checked that we have not more privileges on correspondent column of view
table (i.e. user will not get some privileges by view creation)
*/
if ((check_access(thd, CREATE_VIEW_ACL, view->db, &view->grant.privilege,
0, 0, is_schema_db(view->db)) ||
check_grant(thd, CREATE_VIEW_ACL, view, 0, 1, 0)) ||
(mode != VIEW_CREATE_NEW &&
(check_access(thd, DROP_ACL, view->db, &view->grant.privilege,
0, 0, is_schema_db(view->db)) ||
check_grant(thd, DROP_ACL, view, 0, 1, 0))))
goto err;
for (sl= select_lex; sl; sl= sl->next_select())
{
for (tbl= sl->get_table_list(); tbl; tbl= tbl->next_local)
{
/*
Ensure that we have some privileges on this table, more strict check
will be done on column level after preparation,
*/
if (check_some_access(thd, VIEW_ANY_ACL, tbl))
{
my_error(ER_TABLEACCESS_DENIED_ERROR, MYF(0),
"ANY", thd->security_ctx->priv_user,
thd->security_ctx->priv_host, tbl->table_name);
goto err;
}
/*
Mark this table as a table which will be checked after the prepare
phase
*/
tbl->table_in_first_from_clause= 1;
/*
We need to check only SELECT_ACL for all normal fields, fields for
which we need "any" (SELECT/UPDATE/INSERT/DELETE) privilege will be
checked later
*/
tbl->grant.want_privilege= SELECT_ACL;
/*
Make sure that all rights are loaded to the TABLE::grant field.
tbl->table_name will be correct name of table because VIEWs are
not opened yet.
*/
fill_effective_table_privileges(thd, &tbl->grant, tbl->db,
tbl->table_name);
}
}
if (&lex->select_lex != lex->all_selects_list)
{
/* check tables of subqueries */
for (tbl= tables; tbl; tbl= tbl->next_global)
{
if (!tbl->table_in_first_from_clause)
{
if (check_access(thd, SELECT_ACL, tbl->db,
&tbl->grant.privilege, 0, 0, test(tbl->schema_table)) ||
check_grant(thd, SELECT_ACL, tbl, 0, 1, 0))
goto err;
}
}
}
/*
Mark fields for special privilege check ("any" privilege)
*/
for (sl= select_lex; sl; sl= sl->next_select())
{
List_iterator_fast<Item> it(sl->item_list);
Item *item;
while ((item= it++))
{
Item_field *field;
if ((field= item->filed_for_view_update()))
{
/*
any_privileges may be reset later by the Item_field::set_field
method in case of a system temporary table.
*/
field->any_privileges= 1;
}
}
}
res= FALSE;
err:
DBUG_RETURN(res || thd->is_error());
}
#else
bool create_view_precheck(THD *thd, TABLE_LIST *tables, TABLE_LIST *view,
enum_view_create_mode mode)
{
return FALSE;
}
#endif
/**
@brief Creating/altering VIEW procedure
@param thd thread handler
@param views views to create
@param mode VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE
@note This function handles both create and alter view commands.
@retval FALSE Operation was a success.
@retval TRUE An error occured.
*/
bool mysql_create_view(THD *thd, TABLE_LIST *views,
enum_view_create_mode mode)
{
LEX *lex= thd->lex;
bool link_to_local;
/* first table in list is target VIEW name => cut off it */
TABLE_LIST *view= lex->unlink_first_table(&link_to_local);
TABLE_LIST *tables= lex->query_tables;
TABLE_LIST *tbl;
SELECT_LEX *select_lex= &lex->select_lex;
#ifndef NO_EMBEDDED_ACCESS_CHECKS
SELECT_LEX *sl;
#endif
SELECT_LEX_UNIT *unit= &lex->unit;
bool res= FALSE;
DBUG_ENTER("mysql_create_view");
/* This is ensured in the parser. */
DBUG_ASSERT(!lex->proc_list.first && !lex->result &&
!lex->param_list.elements);
if (mode != VIEW_CREATE_NEW)
{
if (mode == VIEW_ALTER &&
fill_defined_view_parts(thd, view))
{
res= TRUE;
goto err;
}
sp_cache_invalidate();
}
if (!lex->definer)
{
/*
DEFINER-clause is missing; we have to create default definer in
persistent arena to be PS/SP friendly.
If this is an ALTER VIEW then the current user should be set as
the definer.
*/
Query_arena original_arena;
Query_arena *ps_arena = thd->activate_stmt_arena_if_needed(&original_arena);
if (!(lex->definer= create_default_definer(thd)))
res= TRUE;
if (ps_arena)
thd->restore_active_arena(ps_arena, &original_arena);
if (res)
goto err;
}
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/*
check definer of view:
- same as current user
- current user has SUPER_ACL
*/
if (lex->definer &&
(strcmp(lex->definer->user.str, thd->security_ctx->priv_user) != 0 ||
my_strcasecmp(system_charset_info,
lex->definer->host.str,
thd->security_ctx->priv_host) != 0))
{
if (!(thd->security_ctx->master_access & SUPER_ACL))
{
my_error(ER_SPECIFIC_ACCESS_DENIED_ERROR, MYF(0), "SUPER");
res= TRUE;
goto err;
}
else
{
if (!is_acl_user(lex->definer->host.str,
lex->definer->user.str))
{
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_NO_SUCH_USER,
ER(ER_NO_SUCH_USER),
lex->definer->user.str,
lex->definer->host.str);
}
}
}
#endif
if ((res= create_view_precheck(thd, tables, view, mode)))
goto err;
if (open_and_lock_tables(thd, tables))
{
res= TRUE;
goto err;
}
/*
check that tables are not temporary and this VIEW do not used in query
(it is possible with ALTERing VIEW).
open_and_lock_tables can change the value of tables,
e.g. it may happen if before the function call tables was equal to 0.
*/
for (tbl= lex->query_tables; tbl; tbl= tbl->next_global)
{
/* is this table view and the same view which we creates now? */
if (tbl->view &&
strcmp(tbl->view_db.str, view->db) == 0 &&
strcmp(tbl->view_name.str, view->table_name) == 0)
{
my_error(ER_NO_SUCH_TABLE, MYF(0), tbl->view_db.str, tbl->view_name.str);
res= TRUE;
goto err;
}
/*
tbl->table can be NULL when tbl is a placeholder for a view
that is indirectly referenced via a stored function from the
view being created. We don't check these indirectly
referenced views in CREATE VIEW so they don't have table
object.
*/
if (tbl->table)
{
/* is this table temporary and is not view? */
if (tbl->table->s->tmp_table != NO_TMP_TABLE && !tbl->view &&
!tbl->schema_table)
{
my_error(ER_VIEW_SELECT_TMPTABLE, MYF(0), tbl->alias);
res= TRUE;
goto err;
}
/*
Copy the privileges of the underlying VIEWs which were filled by
fill_effective_table_privileges
(they were not copied at derived tables processing)
*/
tbl->table->grant.privilege= tbl->grant.privilege;
}
}
/* prepare select to resolve all fields */
lex->view_prepare_mode= 1;
if (unit->prepare(thd, 0, 0))
{
/*
some errors from prepare are reported to user, if is not then
it will be checked after err: label
*/
res= TRUE;
goto err;
}
/* view list (list of view fields names) */
if (lex->view_list.elements)
{
List_iterator_fast<Item> it(select_lex->item_list);
List_iterator_fast<LEX_STRING> nm(lex->view_list);
Item *item;
LEX_STRING *name;
if (lex->view_list.elements != select_lex->item_list.elements)
{
my_message(ER_VIEW_WRONG_LIST, ER(ER_VIEW_WRONG_LIST), MYF(0));
res= TRUE;
goto err;
}
while ((item= it++, name= nm++))
{
item->set_name(name->str, name->length, system_charset_info);
item->is_autogenerated_name= FALSE;
}
}
if (check_duplicate_names(select_lex->item_list, 1))
{
res= TRUE;
goto err;
}
#ifndef NO_EMBEDDED_ACCESS_CHECKS
/*
Compare/check grants on view with grants of underlying tables
*/
fill_effective_table_privileges(thd, &view->grant, view->db,
view->table_name);
{
Item *report_item= NULL;
uint final_priv= VIEW_ANY_ACL;
for (sl= select_lex; sl; sl= sl->next_select())
{
DBUG_ASSERT(view->db); /* Must be set in the parser */
List_iterator_fast<Item> it(sl->item_list);
Item *item;
while ((item= it++))
{
Item_field *fld= item->filed_for_view_update();
uint priv= (get_column_grant(thd, &view->grant, view->db,
view->table_name, item->name) &
VIEW_ANY_ACL);
if (fld && !fld->field->table->s->tmp_table)
{
final_priv&= fld->have_privileges;
if (~fld->have_privileges & priv)
report_item= item;
}
}
}
if (!final_priv)
{
DBUG_ASSERT(report_item);
my_error(ER_COLUMNACCESS_DENIED_ERROR, MYF(0),
"create view", thd->security_ctx->priv_user,
thd->security_ctx->priv_host, report_item->name,
view->table_name);
res= TRUE;
goto err;
}
}
#endif
if (wait_if_global_read_lock(thd, 0, 0))
{
res= TRUE;
goto err;
}
VOID(pthread_mutex_lock(&LOCK_open));
res= mysql_register_view(thd, view, mode);
if (mysql_bin_log.is_open())
{
String buff;
const LEX_STRING command[3]=
{{ C_STRING_WITH_LEN("CREATE ") },
{ C_STRING_WITH_LEN("ALTER ") },
{ C_STRING_WITH_LEN("CREATE OR REPLACE ") }};
buff.append(command[thd->lex->create_view_mode].str,
command[thd->lex->create_view_mode].length);
view_store_options(thd, views, &buff);
buff.append(STRING_WITH_LEN("VIEW "));
/* Test if user supplied a db (ie: we did not use thd->db) */
if (views->db && views->db[0] &&
(thd->db == NULL || strcmp(views->db, thd->db)))
{
append_identifier(thd, &buff, views->db,
views->db_length);
buff.append('.');
}
append_identifier(thd, &buff, views->table_name,
views->table_name_length);
if (lex->view_list.elements)
{
List_iterator_fast<LEX_STRING> names(lex->view_list);
LEX_STRING *name;
int i;
for (i= 0; (name= names++); i++)
{
buff.append(i ? ", " : "(");
append_identifier(thd, &buff, name->str, name->length);
}
buff.append(')');
}
buff.append(STRING_WITH_LEN(" AS "));
buff.append(views->source.str, views->source.length);
thd->binlog_query(THD::STMT_QUERY_TYPE,
buff.ptr(), buff.length(), FALSE, FALSE);
}
VOID(pthread_mutex_unlock(&LOCK_open));
if (mode != VIEW_CREATE_NEW)
query_cache_invalidate3(thd, view, 0);
start_waiting_global_read_lock(thd);
if (res)
goto err;
my_ok(thd);
lex->link_first_table_back(view, link_to_local);
DBUG_RETURN(0);
err:
thd_proc_info(thd, "end");
lex->link_first_table_back(view, link_to_local);
unit->cleanup();
DBUG_RETURN(res || thd->is_error());
}
/* number of required parameters for making view */
static const int required_view_parameters= 14;
/*
table of VIEW .frm field descriptors
Note that one should NOT change the order for this, as it's used by
parse()
*/
static File_option view_parameters[]=
{{{ C_STRING_WITH_LEN("query")},
my_offsetof(TABLE_LIST, select_stmt),
FILE_OPTIONS_ESTRING},
{{ C_STRING_WITH_LEN("md5")},
my_offsetof(TABLE_LIST, md5),
FILE_OPTIONS_STRING},
{{ C_STRING_WITH_LEN("updatable")},
my_offsetof(TABLE_LIST, updatable_view),
FILE_OPTIONS_ULONGLONG},
{{ C_STRING_WITH_LEN("algorithm")},
my_offsetof(TABLE_LIST, algorithm),
FILE_OPTIONS_ULONGLONG},
{{ C_STRING_WITH_LEN("definer_user")},
my_offsetof(TABLE_LIST, definer.user),
FILE_OPTIONS_STRING},
{{ C_STRING_WITH_LEN("definer_host")},
my_offsetof(TABLE_LIST, definer.host),
FILE_OPTIONS_STRING},
{{ C_STRING_WITH_LEN("suid")},
my_offsetof(TABLE_LIST, view_suid),
FILE_OPTIONS_ULONGLONG},
{{ C_STRING_WITH_LEN("with_check_option")},
my_offsetof(TABLE_LIST, with_check),
FILE_OPTIONS_ULONGLONG},
{{ C_STRING_WITH_LEN("timestamp")},
my_offsetof(TABLE_LIST, timestamp),
FILE_OPTIONS_TIMESTAMP},
{{ C_STRING_WITH_LEN("create-version")},
my_offsetof(TABLE_LIST, file_version),
FILE_OPTIONS_ULONGLONG},
{{ C_STRING_WITH_LEN("source")},
my_offsetof(TABLE_LIST, source),
FILE_OPTIONS_ESTRING},
{{(char*) STRING_WITH_LEN("client_cs_name")},
my_offsetof(TABLE_LIST, view_client_cs_name),
FILE_OPTIONS_STRING},
{{(char*) STRING_WITH_LEN("connection_cl_name")},
my_offsetof(TABLE_LIST, view_connection_cl_name),
FILE_OPTIONS_STRING},
{{(char*) STRING_WITH_LEN("view_body_utf8")},
my_offsetof(TABLE_LIST, view_body_utf8),
FILE_OPTIONS_ESTRING},
{{NullS, 0}, 0,
FILE_OPTIONS_STRING}
};
static LEX_STRING view_file_type[]= {{(char*) STRING_WITH_LEN("VIEW") }};
/*
Register VIEW (write .frm & process .frm's history backups)
SYNOPSIS
mysql_register_view()
thd - thread handler
view - view description
mode - VIEW_CREATE_NEW, VIEW_ALTER, VIEW_CREATE_OR_REPLACE
RETURN
0 OK
-1 Error
1 Error and error message given
*/
static int mysql_register_view(THD *thd, TABLE_LIST *view,
enum_view_create_mode mode)
{
LEX *lex= thd->lex;
/*
View definition query -- a SELECT statement that fully defines view. It
is generated from the Item-tree built from the original (specified by
the user) query. The idea is that generated query should eliminates all
ambiguities and fix view structure at CREATE-time (once for all).
Item::print() virtual operation is used to generate view definition
query.
INFORMATION_SCHEMA query (IS query) -- a SQL statement describing a
view that is shown in INFORMATION_SCHEMA. Basically, it is 'view
definition query' with text literals converted to UTF8 and without
character set introducers.
For example:
Let's suppose we have:
CREATE TABLE t1(a INT, b INT);
User specified query:
CREATE VIEW v1(x, y) AS SELECT * FROM t1;
Generated query:
SELECT a AS x, b AS y FROM t1;
IS query:
SELECT a AS x, b AS y FROM t1;
View definition query is stored in the client character set.
*/
char view_query_buff[4096];
String view_query(view_query_buff,
sizeof (view_query_buff),
thd->charset());
char is_query_buff[4096];
String is_query(is_query_buff,
sizeof (is_query_buff),
system_charset_info);
char md5[MD5_BUFF_LENGTH];
bool can_be_merged;
char dir_buff[FN_REFLEN], path_buff[FN_REFLEN];
LEX_STRING dir, file, path;
int error= 0;
DBUG_ENTER("mysql_register_view");
/* Generate view definition and IS queries. */
view_query.length(0);
is_query.length(0);
{
ulong sql_mode= thd->variables.sql_mode & MODE_ANSI_QUOTES;
thd->variables.sql_mode&= ~MODE_ANSI_QUOTES;
lex->unit.print(&view_query, QT_ORDINARY);
lex->unit.print(&is_query, QT_IS);
thd->variables.sql_mode|= sql_mode;
}
DBUG_PRINT("info", ("View: %s", view_query.ptr()));
/* fill structure */
view->source= thd->lex->create_view_select;
if (!thd->make_lex_string(&view->select_stmt, view_query.ptr(),
view_query.length(), false))
{
my_error(ER_OUT_OF_RESOURCES, MYF(0));
error= -1;
goto err;
}
view->file_version= 1;
view->calc_md5(md5);
if (!(view->md5.str= (char*) thd->memdup(md5, 32)))
{
my_error(ER_OUT_OF_RESOURCES, MYF(0));
error= -1;
goto err;
}
view->md5.length= 32;
can_be_merged= lex->can_be_merged();
if (lex->create_view_algorithm == VIEW_ALGORITHM_MERGE &&
!lex->can_be_merged())
{
push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_VIEW_MERGE,
ER(ER_WARN_VIEW_MERGE));
lex->create_view_algorithm= VIEW_ALGORITHM_UNDEFINED;
}
view->algorithm= lex->create_view_algorithm;
view->definer.user= lex->definer->user;
view->definer.host= lex->definer->host;
view->view_suid= lex->create_view_suid;
view->with_check= lex->create_view_check;
if ((view->updatable_view= (can_be_merged &&
view->algorithm != VIEW_ALGORITHM_TMPTABLE)))
{
/* TODO: change here when we will support UNIONs */
for (TABLE_LIST *tbl= (TABLE_LIST *)lex->select_lex.table_list.first;
tbl;
tbl= tbl->next_local)
{
if ((tbl->view && !tbl->updatable_view) || tbl->schema_table)
{
view->updatable_view= 0;
break;
}
for (TABLE_LIST *up= tbl; up; up= up->embedding)
{
if (up->outer_join)
{
view->updatable_view= 0;
goto loop_out;
}
}
}
}
loop_out:
/* print file name */
dir.length= build_table_filename(dir_buff, sizeof(dir_buff),
view->db, "", "", 0);
dir.str= dir_buff;
path.length= build_table_filename(path_buff, sizeof(path_buff),
view->db, view->table_name, reg_ext, 0);
path.str= path_buff;
file.str= path.str + dir.length;
file.length= path.length - dir.length;
/* init timestamp */
if (!view->timestamp.str)
view->timestamp.str= view->timestamp_buffer;
/* check old .frm */
{
char path_buff[FN_REFLEN];
LEX_STRING path;
File_parser *parser;
path.str= path_buff;
fn_format(path_buff, file.str, dir.str, "", MY_UNPACK_FILENAME);
path.length= strlen(path_buff);
if (!access(path.str, F_OK))
{
if (mode == VIEW_CREATE_NEW)
{
my_error(ER_TABLE_EXISTS_ERROR, MYF(0), view->alias);
error= -1;
goto err;
}
if (!(parser= sql_parse_prepare(&path, thd->mem_root, 0)))
{
error= 1;
goto err;
}
if (!parser->ok() || !is_equal(&view_type, parser->type()))
{
my_error(ER_WRONG_OBJECT, MYF(0), view->db, view->table_name, "VIEW");
error= -1;
goto err;
}
/*
TODO: read dependence list, too, to process cascade/restrict
TODO: special cascade/restrict procedure for alter?
*/
}
else
{
if (mode == VIEW_ALTER)
{
my_error(ER_NO_SUCH_TABLE, MYF(0), view->db, view->alias);
error= -1;
goto err;
}
}
}
/* Initialize view creation context from the environment. */
view->view_creation_ctx= View_creation_ctx::create(thd);
/*
Set LEX_STRING attributes in view-structure for parser to create
frm-file.
*/
lex_string_set(&view->view_client_cs_name,
view->view_creation_ctx->get_client_cs()->csname);
lex_string_set(&view->view_connection_cl_name,
view->view_creation_ctx->get_connection_cl()->name);
if (!thd->make_lex_string(&view->view_body_utf8, is_query.ptr(),
is_query.length(), false))
{
my_error(ER_OUT_OF_RESOURCES, MYF(0));
error= -1;
goto err;
}
/*
Check that table of main select do not used in subqueries.
This test can catch only very simple cases of such non-updateable views,
all other will be detected before updating commands execution.
(it is more optimisation then real check)
NOTE: this skip cases of using table via VIEWs, joined VIEWs, VIEWs with
UNION
*/
if (view->updatable_view &&
!lex->select_lex.master_unit()->is_union() &&
!((TABLE_LIST*)lex->select_lex.table_list.first)->next_local &&
find_table_in_global_list(lex->query_tables->next_global,
lex->query_tables->db,
lex->query_tables->table_name))
{
view->updatable_view= 0;
}
if (view->with_check != VIEW_CHECK_NONE &&
!view->updatable_view)
{
my_error(ER_VIEW_NONUPD_CHECK, MYF(0), view->db, view->table_name);
error= -1;
goto err;
}
if (sql_create_definition_file(&dir, &file, view_file_type,
(uchar*)view, view_parameters))
{
error= thd->is_error() ? -1 : 1;
goto err;
}
DBUG_RETURN(0);
err:
view->select_stmt.str= NULL;
view->select_stmt.length= 0;
view->md5.str= NULL;
view->md5.length= 0;
DBUG_RETURN(error);
}
/*
read VIEW .frm and create structures
SYNOPSIS
mysql_make_view()
thd Thread handler
parser parser object
table TABLE_LIST structure for filling
flags flags
RETURN
0 ok
1 error
*/
bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table,
uint flags)
{
SELECT_LEX *end, *view_select;
LEX *old_lex, *lex;
Query_arena *arena, backup;
TABLE_LIST *top_view= table->top_table();
bool parse_status;
bool result, view_is_mergeable;
TABLE_LIST *view_main_select_tables;
DBUG_ENTER("mysql_make_view");
DBUG_PRINT("info", ("table: 0x%lx (%s)", (ulong) table, table->table_name));
if (table->view)
{
/*
It's an execution of a PS/SP and the view has already been unfolded
into a list of used tables. Now we only need to update the information
about granted privileges in the view tables with the actual data
stored in MySQL privilege system. We don't need to restore the
required privileges (by calling register_want_access) because they has
not changed since PREPARE or the previous execution: the only case
when this information is changed is execution of UPDATE on a view, but
the original want_access is restored in its end.
*/
if (!table->prelocking_placeholder && table->prepare_security(thd))
{
DBUG_RETURN(1);
}
DBUG_PRINT("info",
("VIEW %s.%s is already processed on previous PS/SP execution",
table->view_db.str, table->view_name.str));
DBUG_RETURN(0);
}
if (table->index_hints && table->index_hints->elements)
{
my_error(ER_WRONG_USAGE, MYF(0), "index hints", "VIEW");
DBUG_RETURN(TRUE);
}
/* check loop via view definition */
for (TABLE_LIST *precedent= table->referencing_view;
precedent;
precedent= precedent->referencing_view)
{
if (precedent->view_name.length == table->table_name_length &&
precedent->view_db.length == table->db_length &&
my_strcasecmp(system_charset_info,
precedent->view_name.str, table->table_name) == 0 &&
my_strcasecmp(system_charset_info,
precedent->view_db.str, table->db) == 0)
{
my_error(ER_VIEW_RECURSIVE, MYF(0),
top_view->view_db.str, top_view->view_name.str);
DBUG_RETURN(TRUE);
}
}
/*
For now we assume that tables will not be changed during PS life (it
will be TRUE as far as we make new table cache).
*/
old_lex= thd->lex;
arena= thd->stmt_arena;
if (arena->is_conventional())
arena= 0;
else
thd->set_n_backup_active_arena(arena, &backup);
/* init timestamp */
if (!table->timestamp.str)
table->timestamp.str= table->timestamp_buffer;
/* prepare default values for old format */
table->view_suid= TRUE;
table->definer.user.str= table->definer.host.str= 0;
table->definer.user.length= table->definer.host.length= 0;
/*
TODO: when VIEWs will be stored in cache, table mem_root should
be used here
*/
if (parser->parse((uchar*)table, thd->mem_root, view_parameters,
required_view_parameters, &file_parser_dummy_hook))
goto err;
/*
check old format view .frm
*/
if (!table->definer.user.str)
{
DBUG_ASSERT(!table->definer.host.str &&
!table->definer.user.length &&
!table->definer.host.length);
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
ER_VIEW_FRM_NO_USER, ER(ER_VIEW_FRM_NO_USER),
table->db, table->table_name);
get_default_definer(thd, &table->definer);
}
if (flags & OPEN_VIEW_NO_PARSE)
{
DBUG_RETURN(FALSE);
}
/*
Save VIEW parameters, which will be wiped out by derived table
processing
*/
table->view_db.str= table->db;
table->view_db.length= table->db_length;
table->view_name.str= table->table_name;
table->view_name.length= table->table_name_length;
/*TODO: md5 test here and warning if it is differ */
/*
Initialize view definition context by character set names loaded from
the view definition file. Use UTF8 character set if view definition
file is of old version and does not contain the character set names.
*/
table->view_creation_ctx= View_creation_ctx::create(thd, table);
/*
TODO: TABLE mem root should be used here when VIEW will be stored in
TABLE cache
now Lex placed in statement memory
*/
table->view= lex= thd->lex= (LEX*) new(thd->mem_root) st_lex_local;
{
char old_db_buf[NAME_LEN+1];
LEX_STRING old_db= { old_db_buf, sizeof(old_db_buf) };
bool dbchanged;
Parser_state parser_state(thd,
table->select_stmt.str,
table->select_stmt.length);
/*
Use view db name as thread default database, in order to ensure
that the view is parsed and prepared correctly.
*/
if ((result= mysql_opt_change_db(thd, &table->view_db, &old_db, 1,
&dbchanged)))
goto end;
lex_start(thd);
view_select= &lex->select_lex;
view_select->select_number= ++thd->select_number;
ulong saved_mode= thd->variables.sql_mode;
/* switch off modes which can prevent normal parsing of VIEW
- MODE_REAL_AS_FLOAT affect only CREATE TABLE parsing
+ MODE_PIPES_AS_CONCAT affect expression parsing
+ MODE_ANSI_QUOTES affect expression parsing
+ MODE_IGNORE_SPACE affect expression parsing
- MODE_NOT_USED not used :)
* MODE_ONLY_FULL_GROUP_BY affect execution
* MODE_NO_UNSIGNED_SUBTRACTION affect execution
- MODE_NO_DIR_IN_CREATE affect table creation only
- MODE_POSTGRESQL compounded from other modes
- MODE_ORACLE compounded from other modes
- MODE_MSSQL compounded from other modes
- MODE_DB2 compounded from other modes
- MODE_MAXDB affect only CREATE TABLE parsing
- MODE_NO_KEY_OPTIONS affect only SHOW
- MODE_NO_TABLE_OPTIONS affect only SHOW
- MODE_NO_FIELD_OPTIONS affect only SHOW
- MODE_MYSQL323 affect only SHOW
- MODE_MYSQL40 affect only SHOW
- MODE_ANSI compounded from other modes
(+ transaction mode)
? MODE_NO_AUTO_VALUE_ON_ZERO affect UPDATEs
+ MODE_NO_BACKSLASH_ESCAPES affect expression parsing
*/
thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES |
MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES);
/* Parse the query. */
parse_status= parse_sql(thd, & parser_state, table->view_creation_ctx);
/* Restore environment. */
if ((old_lex->sql_command == SQLCOM_SHOW_FIELDS) ||
(old_lex->sql_command == SQLCOM_SHOW_CREATE))
lex->sql_command= old_lex->sql_command;
thd->variables.sql_mode= saved_mode;
if (dbchanged && mysql_change_db(thd, &old_db, TRUE))
goto err;
}
if (!parse_status)
{
TABLE_LIST *view_tables= lex->query_tables;
TABLE_LIST *view_tables_tail= 0;
TABLE_LIST *tbl;
/*
Check rights to run commands (EXPLAIN SELECT & SHOW CREATE) which show
underlying tables.
Skip this step if we are opening view for prelocking only.
*/
if (!table->prelocking_placeholder &&
(old_lex->sql_command == SQLCOM_SELECT && old_lex->describe))
{
if (check_table_access(thd, SELECT_ACL, view_tables, UINT_MAX, TRUE) &&
check_table_access(thd, SHOW_VIEW_ACL, table, UINT_MAX, TRUE))
{
my_message(ER_VIEW_NO_EXPLAIN, ER(ER_VIEW_NO_EXPLAIN), MYF(0));
goto err;
}
}
else if (!table->prelocking_placeholder &&
(old_lex->sql_command == SQLCOM_SHOW_CREATE) &&
!table->belong_to_view)
{
if (check_table_access(thd, SHOW_VIEW_ACL, table, UINT_MAX, FALSE))
goto err;
}
if (!(table->view_tables=
(List<TABLE_LIST>*) new(thd->mem_root) List<TABLE_LIST>))
goto err;
/*
mark to avoid temporary table using and put view reference and find
last view table
*/
for (tbl= view_tables;
tbl;
tbl= (view_tables_tail= tbl)->next_global)
{
tbl->skip_temporary= 1;
tbl->belong_to_view= top_view;
tbl->referencing_view= table;
tbl->prelocking_placeholder= table->prelocking_placeholder;
/*
First we fill want_privilege with SELECT_ACL (this is needed for the
tables which belongs to view subqueries and temporary table views,
then for the merged view underlying tables we will set wanted
privileges of top_view
*/
tbl->grant.want_privilege= SELECT_ACL;
/*
After unfolding the view we lose the list of tables referenced in it
(we will have only a list of underlying tables in case of MERGE
algorithm, which does not include the tables referenced from
subqueries used in view definition).
Let's build a list of all tables referenced in the view.
*/
table->view_tables->push_back(tbl);
}
/*
Put tables of VIEW after VIEW TABLE_LIST
NOTE: It is important for UPDATE/INSERT/DELETE checks to have this
tables just after VIEW instead of tail of list, to be able check that
table is unique. Also we store old next table for the same purpose.
*/
if (view_tables)
{
if (table->next_global)
{
view_tables_tail->next_global= table->next_global;
table->next_global->prev_global= &view_tables_tail->next_global;
}
else
{
old_lex->query_tables_last= &view_tables_tail->next_global;
}
view_tables->prev_global= &table->next_global;
table->next_global= view_tables;
}
/*
If the view's body needs row-based binlogging (e.g. the VIEW is created
from SELECT UUID()), the top statement also needs it.
*/
if (lex->is_stmt_unsafe())
old_lex->set_stmt_unsafe();
view_is_mergeable= (table->algorithm != VIEW_ALGORITHM_TMPTABLE &&
lex->can_be_merged());
LINT_INIT(view_main_select_tables);
if (view_is_mergeable)
{
/*
Currently 'view_main_select_tables' differs from 'view_tables'
only then view has CONVERT_TZ() function in its select list.
This may change in future, for example if we enable merging of
views with subqueries in select list.
*/
view_main_select_tables=
(TABLE_LIST*)lex->select_lex.table_list.first;
/*
Let us set proper lock type for tables of the view's main
select since we may want to perform update or insert on
view. This won't work for view containing union. But this is
ok since we don't allow insert and update on such views
anyway.
*/
for (tbl= view_main_select_tables; tbl; tbl= tbl->next_local)
tbl->lock_type= table->lock_type;
/*
If the view is mergeable, we might want to
INSERT/UPDATE/DELETE into tables of this view. Preserve the
original sql command and 'duplicates' of the outer lex.
This is used later in set_trg_event_type_for_command.
*/
lex->sql_command= old_lex->sql_command;
lex->duplicates= old_lex->duplicates;
}
/*
This method has a dependency on the proper lock type being set,
so in case of views should be called here.
*/
lex->set_trg_event_type_for_tables();
/*
If we are opening this view as part of implicit LOCK TABLES, then
this view serves as simple placeholder and we should not continue
further processing.
*/
if (table->prelocking_placeholder)
goto ok2;
old_lex->derived_tables|= (DERIVED_VIEW | lex->derived_tables);
/* move SQL_NO_CACHE & Co to whole query */
old_lex->safe_to_cache_query= (old_lex->safe_to_cache_query &&
lex->safe_to_cache_query);
/* move SQL_CACHE to whole query */
if (view_select->options & OPTION_TO_QUERY_CACHE)
old_lex->select_lex.options|= OPTION_TO_QUERY_CACHE;
if (table->view_suid)
{
/*
Prepare a security context to check underlying objects of the view
*/
if (!(table->view_sctx= (Security_context *)
thd->stmt_arena->alloc(sizeof(Security_context))))
goto err;
/* Assign the context to the tables referenced in the view */
if (view_tables)
{
DBUG_ASSERT(view_tables_tail);
for (tbl= view_tables; tbl != view_tables_tail->next_global;
tbl= tbl->next_global)
tbl->security_ctx= table->view_sctx;
}
/* assign security context to SELECT name resolution contexts of view */
for(SELECT_LEX *sl= lex->all_selects_list;
sl;
sl= sl->next_select_in_list())
sl->context.security_ctx= table->view_sctx;
}
/*
Setup an error processor to hide error messages issued by stored
routines referenced in the view
*/
for (SELECT_LEX *sl= lex->all_selects_list;
sl;
sl= sl->next_select_in_list())
{
sl->context.error_processor= &view_error_processor;
sl->context.error_processor_data= (void *)table;
}
/*
check MERGE algorithm ability
- algorithm is not explicit TEMPORARY TABLE
- VIEW SELECT allow merging
- VIEW used in subquery or command support MERGE algorithm
*/
if (view_is_mergeable &&
(table->select_lex->master_unit() != &old_lex->unit ||
old_lex->can_use_merged()) &&
!old_lex->can_not_use_merged())
{
/* lex should contain at least one table */
DBUG_ASSERT(view_main_select_tables != 0);
List_iterator_fast<TABLE_LIST> ti(view_select->top_join_list);
table->effective_algorithm= VIEW_ALGORITHM_MERGE;
DBUG_PRINT("info", ("algorithm: MERGE"));
table->updatable= (table->updatable_view != 0);
table->effective_with_check=
old_lex->get_effective_with_check(table);
table->merge_underlying_list= view_main_select_tables;
/* Fill correct wanted privileges. */
for (tbl= view_main_select_tables; tbl; tbl= tbl->next_local)
tbl->grant.want_privilege= top_view->grant.orig_want_privilege;
/* prepare view context */
lex->select_lex.context.resolve_in_table_list_only(view_main_select_tables);
lex->select_lex.context.outer_context= 0;
lex->select_lex.context.select_lex= table->select_lex;
lex->select_lex.select_n_having_items+=
table->select_lex->select_n_having_items;
/*
Tables of the main select of the view should be marked as belonging
to the same select as original view (again we can use LEX::select_lex
for this purprose because we don't support MERGE algorithm for views
with unions).
*/
for (tbl= lex->select_lex.get_table_list(); tbl; tbl= tbl->next_local)
tbl->select_lex= table->select_lex;
{
if (view_main_select_tables->next_local)
{
table->multitable_view= TRUE;
if (table->belong_to_view)
table->belong_to_view->multitable_view= TRUE;
}
/* make nested join structure for view tables */
NESTED_JOIN *nested_join;
if (!(nested_join= table->nested_join=
(NESTED_JOIN *) thd->calloc(sizeof(NESTED_JOIN))))
goto err;
nested_join->join_list= view_select->top_join_list;
/* re-nest tables of VIEW */
ti.rewind();
while ((tbl= ti++))
{
tbl->join_list= &nested_join->join_list;
tbl->embedding= table;
}
}
/* Store WHERE clause for post-processing in setup_underlying */
table->where= view_select->where;
/*
Add subqueries units to SELECT into which we merging current view.
unit(->next)* chain starts with subqueries that are used by this
view and continues with subqueries that are used by other views.
We must not add any subquery twice (otherwise we'll form a loop),
to do this we remember in end_unit the first subquery that has
been already added.
NOTE: we do not support UNION here, so we take only one select
*/
SELECT_LEX_NODE *end_unit= table->select_lex->slave;
SELECT_LEX_UNIT *next_unit;
for (SELECT_LEX_UNIT *unit= lex->select_lex.first_inner_unit();
unit;
unit= next_unit)
{
if (unit == end_unit)
break;
SELECT_LEX_NODE *save_slave= unit->slave;
next_unit= unit->next_unit();
unit->include_down(table->select_lex);
unit->slave= save_slave; // fix include_down initialisation
}
/*
We can safely ignore the VIEW's ORDER BY if we merge into union
branch, as order is not important there.
*/
if (!table->select_lex->master_unit()->is_union())
table->select_lex->order_list.push_back(&lex->select_lex.order_list);
/*
This SELECT_LEX will be linked in global SELECT_LEX list
to make it processed by mysql_handle_derived(),
but it will not be included to SELECT_LEX tree, because it
will not be executed
*/
goto ok;
}
table->effective_algorithm= VIEW_ALGORITHM_TMPTABLE;
DBUG_PRINT("info", ("algorithm: TEMPORARY TABLE"));
view_select->linkage= DERIVED_TABLE_TYPE;
table->updatable= 0;
table->effective_with_check= VIEW_CHECK_NONE;
old_lex->subqueries= TRUE;
/* SELECT tree link */
lex->unit.include_down(table->select_lex);
lex->unit.slave= view_select; // fix include_down initialisation
table->derived= &lex->unit;
}
else
goto err;
ok:
/* global SELECT list linking */
end= view_select; // primary SELECT_LEX is always last
end->link_next= old_lex->all_selects_list;
old_lex->all_selects_list->link_prev= &end->link_next;
old_lex->all_selects_list= lex->all_selects_list;
lex->all_selects_list->link_prev=
(st_select_lex_node**)&old_lex->all_selects_list;
ok2:
DBUG_ASSERT(lex == thd->lex);
thd->lex= old_lex; // Needed for prepare_security
result= !table->prelocking_placeholder && table->prepare_security(thd);
lex_end(lex);
end:
if (arena)
thd->restore_active_arena(arena, &backup);
thd->lex= old_lex;
DBUG_RETURN(result);
err:
DBUG_ASSERT(thd->lex == table->view);
lex_end(thd->lex);
delete table->view;
table->view= 0; // now it is not VIEW placeholder
result= 1;
goto end;
}
/*
drop view
SYNOPSIS
mysql_drop_view()
thd - thread handler
views - views to delete
drop_mode - cascade/check
RETURN VALUE
FALSE OK
TRUE Error
*/
bool mysql_drop_view(THD *thd, TABLE_LIST *views, enum_drop_mode drop_mode)
{
char path[FN_REFLEN];
TABLE_LIST *view;
String non_existant_views;
char *wrong_object_db= NULL, *wrong_object_name= NULL;
bool error= FALSE;
enum legacy_db_type not_used;
bool some_views_deleted= FALSE;
bool something_wrong= FALSE;
DBUG_ENTER("mysql_drop_view");
VOID(pthread_mutex_lock(&LOCK_open));
for (view= views; view; view= view->next_local)
{
TABLE_SHARE *share;
frm_type_enum type= FRMTYPE_ERROR;
build_table_filename(path, sizeof(path),
view->db, view->table_name, reg_ext, 0);
if (access(path, F_OK) ||
FRMTYPE_VIEW != (type= mysql_frm_type(thd, path, &not_used)))
{
char name[FN_REFLEN];
my_snprintf(name, sizeof(name), "%s.%s", view->db, view->table_name);
if (thd->lex->drop_if_exists)
{
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_BAD_TABLE_ERROR, ER(ER_BAD_TABLE_ERROR),
name);
continue;
}
if (type == FRMTYPE_TABLE)
{
if (!wrong_object_name)
{
wrong_object_db= view->db;
wrong_object_name= view->table_name;
}
}
else
{
if (non_existant_views.length())
non_existant_views.append(',');
non_existant_views.append(String(view->table_name,system_charset_info));
}
continue;
}
if (my_delete(path, MYF(MY_WME)))
error= TRUE;
some_views_deleted= TRUE;
/*
For a view, there is only one table_share object which should never
be used outside of LOCK_open
*/
if ((share= get_cached_table_share(view->db, view->table_name)))
{
DBUG_ASSERT(share->ref_count == 0);
pthread_mutex_lock(&share->mutex);
share->ref_count++;
share->version= 0;
pthread_mutex_unlock(&share->mutex);
release_table_share(share, RELEASE_WAIT_FOR_DROP);
}
query_cache_invalidate3(thd, view, 0);
sp_cache_invalidate();
}
if (wrong_object_name)
{
my_error(ER_WRONG_OBJECT, MYF(0), wrong_object_db, wrong_object_name,
"VIEW");
}
if (non_existant_views.length())
{
my_error(ER_BAD_TABLE_ERROR, MYF(0), non_existant_views.c_ptr());
}
something_wrong= error || wrong_object_name || non_existant_views.length();
if (some_views_deleted || !something_wrong)
{
/* if something goes wrong, bin-log with possible error code,
otherwise bin-log with error code cleared.
*/
write_bin_log(thd, !something_wrong, thd->query, thd->query_length);
}
VOID(pthread_mutex_unlock(&LOCK_open));
if (something_wrong)
{
DBUG_RETURN(TRUE);
}
my_ok(thd);
DBUG_RETURN(FALSE);
}
/*
Check type of .frm if we are not going to parse it
SYNOPSIS
mysql_frm_type()
path path to file
RETURN
FRMTYPE_ERROR error
FRMTYPE_TABLE table
FRMTYPE_VIEW view
*/
frm_type_enum mysql_frm_type(THD *thd, char *path, enum legacy_db_type *dbt)
{
File file;
uchar header[10]; //"TYPE=VIEW\n" it is 10 characters
int error;
DBUG_ENTER("mysql_frm_type");
*dbt= DB_TYPE_UNKNOWN;
if ((file= my_open(path, O_RDONLY | O_SHARE, MYF(0))) < 0)
DBUG_RETURN(FRMTYPE_ERROR);
error= my_read(file, (uchar*) header, sizeof(header), MYF(MY_NABP));
my_close(file, MYF(MY_WME));
if (error)
DBUG_RETURN(FRMTYPE_ERROR);
if (!strncmp((char*) header, "TYPE=VIEW\n", sizeof(header)))
DBUG_RETURN(FRMTYPE_VIEW);
/*
This is just a check for DB_TYPE. We'll return default unknown type
if the following test is true (arg #3). This should not have effect
on return value from this function (default FRMTYPE_TABLE)
*/
if (header[0] != (uchar) 254 || header[1] != 1 ||
(header[2] != FRM_VER && header[2] != FRM_VER+1 &&
(header[2] < FRM_VER+3 || header[2] > FRM_VER+4)))
DBUG_RETURN(FRMTYPE_TABLE);
*dbt= (enum legacy_db_type) (uint) *(header + 3);
DBUG_RETURN(FRMTYPE_TABLE); // Is probably a .frm table
}
/*
check of key (primary or unique) presence in updatable view
SYNOPSIS
check_key_in_view()
thd thread handler
view view for check with opened table
DESCRIPTION
If it is VIEW and query have LIMIT clause then check that underlying
table of view contain one of following:
1) primary key of underlying table
2) unique key underlying table with fields for which NULL value is
impossible
3) all fields of underlying table
RETURN
FALSE OK
TRUE view do not contain key or all fields
*/
bool check_key_in_view(THD *thd, TABLE_LIST *view)
{
TABLE *table;
Field_translator *trans, *end_of_trans;
KEY *key_info, *key_info_end;
DBUG_ENTER("check_key_in_view");
/*
we do not support updatable UNIONs in VIEW, so we can check just limit of
LEX::select_lex
*/
if ((!view->view && !view->belong_to_view) ||
thd->lex->sql_command == SQLCOM_INSERT ||
thd->lex->select_lex.select_limit == 0)
DBUG_RETURN(FALSE); /* it is normal table or query without LIMIT */
table= view->table;
view= view->top_table();
trans= view->field_translation;
key_info_end= (key_info= table->key_info)+ table->s->keys;
end_of_trans= view->field_translation_end;
DBUG_ASSERT(table != 0 && view->field_translation != 0);
{
/*
We should be sure that all fields are ready to get keys from them, but
this operation should not have influence on Field::query_id, to avoid
marking as used fields which are not used
*/
enum_mark_columns save_mark_used_columns= thd->mark_used_columns;
thd->mark_used_columns= MARK_COLUMNS_NONE;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
for (Field_translator *fld= trans; fld < end_of_trans; fld++)
{
if (!fld->item->fixed && fld->item->fix_fields(thd, &fld->item))
{
thd->mark_used_columns= save_mark_used_columns;
return TRUE;
}
}
thd->mark_used_columns= save_mark_used_columns;
DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
}
/* Loop over all keys to see if a unique-not-null key is used */
for (;key_info != key_info_end ; key_info++)
{
if ((key_info->flags & (HA_NOSAME | HA_NULL_PART_KEY)) == HA_NOSAME)
{
KEY_PART_INFO *key_part= key_info->key_part;
KEY_PART_INFO *key_part_end= key_part + key_info->key_parts;
/* check that all key parts are used */
for (;;)
{
Field_translator *k;
for (k= trans; k < end_of_trans; k++)
{
Item_field *field;
if ((field= k->item->filed_for_view_update()) &&
field->field == key_part->field)
break;
}
if (k == end_of_trans)
break; // Key is not possible
if (++key_part == key_part_end)
DBUG_RETURN(FALSE); // Found usable key
}
}
}
DBUG_PRINT("info", ("checking if all fields of table are used"));
/* check all fields presence */
{
Field **field_ptr;
Field_translator *fld;
for (field_ptr= table->field; *field_ptr; field_ptr++)
{
for (fld= trans; fld < end_of_trans; fld++)
{
Item_field *field;
if ((field= fld->item->filed_for_view_update()) &&
field->field == *field_ptr)
break;
}
if (fld == end_of_trans) // If field didn't exists
{
/*
Keys or all fields of underlying tables are not found => we have
to check variable updatable_views_with_limit to decide should we
issue an error or just a warning
*/
if (thd->variables.updatable_views_with_limit)
{
/* update allowed, but issue warning */
push_warning(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_WARN_VIEW_WITHOUT_KEY, ER(ER_WARN_VIEW_WITHOUT_KEY));
DBUG_RETURN(FALSE);
}
/* prohibit update */
DBUG_RETURN(TRUE);
}
}
}
DBUG_RETURN(FALSE);
}
/*
insert fields from VIEW (MERGE algorithm) into given list
SYNOPSIS
insert_view_fields()
thd thread handler
list list for insertion
view view for processing
RETURN
FALSE OK
TRUE error (is not sent to cliet)
*/
bool insert_view_fields(THD *thd, List<Item> *list, TABLE_LIST *view)
{
Field_translator *trans_end;
Field_translator *trans;
DBUG_ENTER("insert_view_fields");
if (!(trans= view->field_translation))
DBUG_RETURN(FALSE);
trans_end= view->field_translation_end;
for (Field_translator *entry= trans; entry < trans_end; entry++)
{
Item_field *fld;
if ((fld= entry->item->filed_for_view_update()))
list->push_back(fld);
else
{
my_error(ER_NON_INSERTABLE_TABLE, MYF(0), view->alias, "INSERT");
DBUG_RETURN(TRUE);
}
}
DBUG_RETURN(FALSE);
}
/*
checking view md5 check suum
SINOPSYS
view_checksum()
thd threar handler
view view for check
RETUIRN
HA_ADMIN_OK OK
HA_ADMIN_NOT_IMPLEMENTED it is not VIEW
HA_ADMIN_WRONG_CHECKSUM check sum is wrong
*/
int view_checksum(THD *thd, TABLE_LIST *view)
{
char md5[MD5_BUFF_LENGTH];
if (!view->view || view->md5.length != 32)
return HA_ADMIN_NOT_IMPLEMENTED;
view->calc_md5(md5);
return (strncmp(md5, view->md5.str, 32) ?
HA_ADMIN_WRONG_CHECKSUM :
HA_ADMIN_OK);
}
/*
rename view
Synopsis:
renames a view
Parameters:
thd thread handler
new_name new name of view
view view
Return values:
FALSE Ok
TRUE Error
*/
bool
mysql_rename_view(THD *thd,
const char *new_name,
TABLE_LIST *view)
{
LEX_STRING pathstr;
File_parser *parser;
char path_buff[FN_REFLEN];
bool error= TRUE;
DBUG_ENTER("mysql_rename_view");
pathstr.str= (char *) path_buff;
pathstr.length= build_table_filename(path_buff, sizeof(path_buff) - 1,
view->db, view->table_name,
reg_ext, 0);
if ((parser= sql_parse_prepare(&pathstr, thd->mem_root, 1)) &&
is_equal(&view_type, parser->type()))
{
TABLE_LIST view_def;
char dir_buff[FN_REFLEN];
LEX_STRING dir, file;
/*
To be PS-friendly we should either to restore state of
TABLE_LIST object pointed by 'view' after using it for
view definition parsing or use temporary 'view_def'
object for it.
*/
bzero(&view_def, sizeof(view_def));
view_def.timestamp.str= view_def.timestamp_buffer;
view_def.view_suid= TRUE;
/* get view definition and source */
if (parser->parse((uchar*)&view_def, thd->mem_root, view_parameters,
array_elements(view_parameters)-1,
&file_parser_dummy_hook))
goto err;
/* rename view and it's backups */
if (rename_in_schema_file(thd, view->db, view->table_name, new_name))
goto err;
dir.str= dir_buff;
dir.length= build_table_filename(dir_buff, sizeof(dir_buff) - 1,
view->db, "", "", 0);
pathstr.str= path_buff;
pathstr.length= build_table_filename(path_buff, sizeof(path_buff) - 1,
view->db, new_name, reg_ext, 0);
file.str= pathstr.str + dir.length;
file.length= pathstr.length - dir.length;
if (sql_create_definition_file(&dir, &file, view_file_type,
(uchar*)&view_def, view_parameters))
{
/* restore renamed view in case of error */
rename_in_schema_file(thd, view->db, new_name, view->table_name);
goto err;
}
} else
DBUG_RETURN(1);
/* remove cache entries */
query_cache_invalidate3(thd, view, 0);
sp_cache_invalidate();
error= FALSE;
err:
DBUG_RETURN(error);
}
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