51
void Item_func::set_arguments(List<Item> &list)
54
arg_count=list.elements;
55
args= tmp_arg; // If 2 arguments
56
if (arg_count <= 2 || (args=(Item**) sql_alloc(sizeof(Item*)*arg_count)))
58
List_iterator_fast<Item> li(list);
60
Item **save_args= args;
65
with_sum_func|=item->with_sum_func;
68
list.empty(); // Fields are used
71
Item_func::Item_func(List<Item> &list)
77
Item_func::Item_func(THD *thd, Item_func *item)
78
:Item_result_field(thd, item),
79
allowed_arg_cols(item->allowed_arg_cols),
80
arg_count(item->arg_count),
81
used_tables_cache(item->used_tables_cache),
82
not_null_tables_cache(item->not_null_tables_cache),
83
const_item_cache(item->const_item_cache)
91
if (!(args=(Item**) thd->alloc(sizeof(Item*)*arg_count)))
94
memcpy(args, item->args, sizeof(Item*)*arg_count);
100
Resolve references to table column for a function and its argument
105
ref Pointer to where this object is used. This reference
106
is used if we want to replace this object with another
107
one (for example in the summary functions).
110
Call fix_fields() for all arguments to the function. The main intention
111
is to allow all Item_field() objects to setup pointers to the table fields.
113
Sets as a side effect the following class variables:
114
maybe_null Set if any argument may return NULL
115
with_sum_func Set if any of the arguments contains a sum function
116
used_tables_cache Set to union of the tables used by arguments
118
str_value.charset If this is a string function, set this to the
119
character set for the first argument.
120
If any argument is binary, this is set to binary
122
If for any item any of the defaults are wrong, then this can
123
be fixed in the fix_length_and_dec() function that is called
124
after this one or by writing a specialized fix_fields() for the
129
true Got error. Stored with my_error().
133
Item_func::fix_fields(THD *thd, Item **ref __attribute__((unused)))
136
Item **arg,**arg_end;
137
void *save_thd_marker= thd->thd_marker;
138
unsigned char buff[STACK_BUFF_ALLOC]; // Max argument in function
140
used_tables_cache= not_null_tables_cache= 0;
143
if (check_stack_overrun(thd, STACK_MIN_SIZE, buff))
144
return true; // Fatal error if flag is set!
146
{ // Print purify happy
147
for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
151
We can't yet set item to *arg as fix_fields may change *arg
152
We shouldn't call fix_fields() twice, so check 'fixed' field first
154
if ((!(*arg)->fixed && (*arg)->fix_fields(thd, arg)))
155
return true; /* purecov: inspected */
158
if (allowed_arg_cols)
160
if (item->check_cols(allowed_arg_cols))
165
/* we have to fetch allowed_arg_cols from first argument */
166
assert(arg == args); // it is first argument
167
allowed_arg_cols= item->cols();
168
assert(allowed_arg_cols); // Can't be 0 any more
171
if (item->maybe_null)
174
with_sum_func= with_sum_func || item->with_sum_func;
175
used_tables_cache|= item->used_tables();
176
not_null_tables_cache|= item->not_null_tables();
177
const_item_cache&= item->const_item();
178
with_subselect|= item->with_subselect;
181
fix_length_and_dec();
182
if (thd->is_error()) // An error inside fix_length_and_dec occured
185
thd->thd_marker= save_thd_marker;
190
void Item_func::fix_after_pullout(st_select_lex *new_parent,
191
Item **ref __attribute__((unused)))
193
Item **arg,**arg_end;
195
used_tables_cache= not_null_tables_cache= 0;
200
for (arg=args, arg_end=args+arg_count; arg != arg_end ; arg++)
202
(*arg)->fix_after_pullout(new_parent, arg);
205
used_tables_cache|= item->used_tables();
206
not_null_tables_cache|= item->not_null_tables();
207
const_item_cache&= item->const_item();
213
bool Item_func::walk(Item_processor processor, bool walk_subquery,
214
unsigned char *argument)
218
Item **arg,**arg_end;
219
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
221
if ((*arg)->walk(processor, walk_subquery, argument))
225
return (this->*processor)(argument);
228
void Item_func::traverse_cond(Cond_traverser traverser,
229
void *argument, traverse_order order)
233
Item **arg,**arg_end;
237
(*traverser)(this, argument);
238
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
240
(*arg)->traverse_cond(traverser, argument, order);
244
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
246
(*arg)->traverse_cond(traverser, argument, order);
248
(*traverser)(this, argument);
252
(*traverser)(this, argument);
257
Transform an Item_func object with a transformer callback function.
259
The function recursively applies the transform method to each
260
argument of the Item_func node.
261
If the call of the method for an argument item returns a new item
262
the old item is substituted for a new one.
263
After this the transformer is applied to the root node
264
of the Item_func object.
265
@param transformer the transformer callback function to be applied to
266
the nodes of the tree of the object
267
@param argument parameter to be passed to the transformer
270
Item returned as the result of transformation of the root node
273
Item *Item_func::transform(Item_transformer transformer, unsigned char *argument)
277
Item **arg,**arg_end;
278
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
280
Item *new_item= (*arg)->transform(transformer, argument);
285
THD::change_item_tree() should be called only if the tree was
286
really transformed, i.e. when a new item has been created.
287
Otherwise we'll be allocating a lot of unnecessary memory for
288
change records at each execution.
290
if (*arg != new_item)
291
current_thd->change_item_tree(arg, new_item);
294
return (this->*transformer)(argument);
299
Compile Item_func object with a processor and a transformer
302
First the function applies the analyzer to the root node of
303
the Item_func object. Then if the analizer succeeeds (returns true)
304
the function recursively applies the compile method to each argument
305
of the Item_func node.
306
If the call of the method for an argument item returns a new item
307
the old item is substituted for a new one.
308
After this the transformer is applied to the root node
309
of the Item_func object.
311
@param analyzer the analyzer callback function to be applied to the
312
nodes of the tree of the object
313
@param[in,out] arg_p parameter to be passed to the processor
314
@param transformer the transformer callback function to be applied to the
315
nodes of the tree of the object
316
@param arg_t parameter to be passed to the transformer
319
Item returned as the result of transformation of the root node
322
Item *Item_func::compile(Item_analyzer analyzer, unsigned char **arg_p,
323
Item_transformer transformer, unsigned char *arg_t)
325
if (!(this->*analyzer)(arg_p))
329
Item **arg,**arg_end;
330
for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
333
The same parameter value of arg_p must be passed
334
to analyze any argument of the condition formula.
336
unsigned char *arg_v= *arg_p;
337
Item *new_item= (*arg)->compile(analyzer, &arg_v, transformer, arg_t);
338
if (new_item && *arg != new_item)
339
current_thd->change_item_tree(arg, new_item);
342
return (this->*transformer)(arg_t);
346
See comments in Item_cmp_func::split_sum_func()
349
void Item_func::split_sum_func(THD *thd, Item **ref_pointer_array,
352
Item **arg, **arg_end;
353
for (arg= args, arg_end= args+arg_count; arg != arg_end ; arg++)
354
(*arg)->split_sum_func2(thd, ref_pointer_array, fields, arg, true);
358
void Item_func::update_used_tables()
362
for (uint32_t i=0 ; i < arg_count ; i++)
364
args[i]->update_used_tables();
365
used_tables_cache|=args[i]->used_tables();
366
const_item_cache&=args[i]->const_item();
371
table_map Item_func::used_tables() const
373
return used_tables_cache;
377
table_map Item_func::not_null_tables() const
379
return not_null_tables_cache;
383
void Item_func::print(String *str, enum_query_type query_type)
385
str->append(func_name());
387
print_args(str, 0, query_type);
392
void Item_func::print_args(String *str, uint32_t from, enum_query_type query_type)
394
for (uint32_t i=from ; i < arg_count ; i++)
398
args[i]->print(str, query_type);
403
void Item_func::print_op(String *str, enum_query_type query_type)
406
for (uint32_t i=0 ; i < arg_count-1 ; i++)
408
args[i]->print(str, query_type);
410
str->append(func_name());
413
args[arg_count-1]->print(str, query_type);
418
bool Item_func::eq(const Item *item, bool binary_cmp) const
420
/* Assume we don't have rtti */
423
if (item->type() != FUNC_ITEM)
425
Item_func *item_func=(Item_func*) item;
426
Item_func::Functype func_type;
427
if ((func_type= functype()) != item_func->functype() ||
428
arg_count != item_func->arg_count ||
429
(func_type != Item_func::FUNC_SP &&
430
func_name() != item_func->func_name()) ||
431
(func_type == Item_func::FUNC_SP &&
432
my_strcasecmp(system_charset_info, func_name(), item_func->func_name())))
434
for (uint32_t i=0; i < arg_count ; i++)
435
if (!args[i]->eq(item_func->args[i], binary_cmp))
441
Field *Item_func::tmp_table_field(Table *table)
445
switch (result_type()) {
447
if (max_length > MY_INT32_NUM_DECIMAL_DIGITS)
448
field= new Field_int64_t(max_length, maybe_null, name, unsigned_flag);
450
field= new Field_long(max_length, maybe_null, name, unsigned_flag);
453
field= new Field_double(max_length, maybe_null, name, decimals);
456
return make_string_field(table);
459
field= new Field_new_decimal(my_decimal_precision_to_length(decimal_precision(),
462
maybe_null, name, decimals, unsigned_flag);
466
// This case should never be chosen
477
my_decimal *Item_func::val_decimal(my_decimal *decimal_value)
480
int2my_decimal(E_DEC_FATAL_ERROR, val_int(), unsigned_flag, decimal_value);
481
return decimal_value;
485
52
String *Item_real_func::val_str(String *str)
added
removed
drizzled/item_func.cc
