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item_cmpfunc.h
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1961 lines (1739 loc) · 60.2 KB
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#ifndef ITEM_CMPFUNC_INCLUDED
#define ITEM_CMPFUNC_INCLUDED
/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/* compare and test functions */
#include "thr_malloc.h" /* sql_calloc */
#include "item_func.h" /* Item_int_func, Item_bool_func */
#include "my_regex.h"
extern Item_result item_cmp_type(Item_result a,Item_result b);
class Item_bool_func2;
class Arg_comparator;
typedef int (Arg_comparator::*arg_cmp_func)();
typedef int (*Item_field_cmpfunc)(Item_field *f1, Item_field *f2, void *arg);
class Arg_comparator: public Sql_alloc
{
Item **a, **b;
arg_cmp_func func;
Item_result_field *owner;
Arg_comparator *comparators; // used only for compare_row()
double precision;
/* Fields used in DATE/DATETIME comparison. */
THD *thd;
enum_field_types a_type, b_type; // Types of a and b items
Item *a_cache, *b_cache; // Cached values of a and b items
bool is_nulls_eq; // TRUE <=> compare for the EQUAL_FUNC
bool set_null; // TRUE <=> set owner->null_value
// when one of arguments is NULL.
longlong (*get_value_a_func)(THD *thd, Item ***item_arg, Item **cache_arg,
Item *warn_item, bool *is_null);
longlong (*get_value_b_func)(THD *thd, Item ***item_arg, Item **cache_arg,
Item *warn_item, bool *is_null);
bool try_year_cmp_func(Item_result type);
static bool get_date_from_const(Item *date_arg, Item *str_arg,
ulonglong *value);
public:
DTCollation cmp_collation;
/* Allow owner function to use string buffers. */
String value1, value2;
Arg_comparator(): comparators(0), thd(0), a_cache(0), b_cache(0), set_null(TRUE),
get_value_a_func(0), get_value_b_func(0) {};
Arg_comparator(Item **a1, Item **a2): a(a1), b(a2), comparators(0), thd(0),
a_cache(0), b_cache(0), set_null(TRUE),
get_value_a_func(0), get_value_b_func(0) {};
int set_compare_func(Item_result_field *owner, Item_result type);
inline int set_compare_func(Item_result_field *owner_arg)
{
return set_compare_func(owner_arg, item_cmp_type((*a)->result_type(),
(*b)->result_type()));
}
int set_cmp_func(Item_result_field *owner_arg,
Item **a1, Item **a2,
Item_result type);
inline int set_cmp_func(Item_result_field *owner_arg,
Item **a1, Item **a2, bool set_null_arg)
{
set_null= set_null_arg;
return set_cmp_func(owner_arg, a1, a2,
item_cmp_type((*a1)->result_type(),
(*a2)->result_type()));
}
inline int compare() { return (this->*func)(); }
int compare_string(); // compare args[0] & args[1]
int compare_binary_string(); // compare args[0] & args[1]
int compare_real(); // compare args[0] & args[1]
int compare_decimal(); // compare args[0] & args[1]
int compare_int_signed(); // compare args[0] & args[1]
int compare_int_signed_unsigned();
int compare_int_unsigned_signed();
int compare_int_unsigned();
int compare_time_packed();
int compare_e_time_packed();
int compare_row(); // compare args[0] & args[1]
int compare_e_string(); // compare args[0] & args[1]
int compare_e_binary_string(); // compare args[0] & args[1]
int compare_e_real(); // compare args[0] & args[1]
int compare_e_decimal(); // compare args[0] & args[1]
int compare_e_int(); // compare args[0] & args[1]
int compare_e_int_diff_signedness();
int compare_e_row(); // compare args[0] & args[1]
int compare_real_fixed();
int compare_e_real_fixed();
int compare_datetime(); // compare args[0] & args[1] as DATETIMEs
static bool can_compare_as_dates(Item *a, Item *b, ulonglong *const_val_arg);
Item** cache_converted_constant(THD *thd, Item **value, Item **cache,
Item_result type);
void set_datetime_cmp_func(Item_result_field *owner_arg, Item **a1, Item **b1);
static arg_cmp_func comparator_matrix [5][2];
inline bool is_owner_equal_func()
{
return (owner->type() == Item::FUNC_ITEM &&
((Item_func*)owner)->functype() == Item_func::EQUAL_FUNC);
}
void cleanup()
{
delete [] comparators;
comparators= 0;
}
/*
Set correct cmp_context if items would be compared as INTs.
*/
inline void set_cmp_context_for_datetime()
{
DBUG_ASSERT(func == &Arg_comparator::compare_datetime);
if ((*a)->is_temporal())
(*a)->cmp_context= INT_RESULT;
if ((*b)->is_temporal())
(*b)->cmp_context= INT_RESULT;
}
friend class Item_func;
};
class Item_bool_func :public Item_int_func
{
public:
Item_bool_func() : Item_int_func(), m_created_by_in2exists(false) {}
Item_bool_func(Item *a) : Item_int_func(a),
m_created_by_in2exists(false) {}
Item_bool_func(Item *a,Item *b) : Item_int_func(a,b),
m_created_by_in2exists(false) {}
Item_bool_func(THD *thd, Item_bool_func *item) : Item_int_func(thd, item),
m_created_by_in2exists(item->m_created_by_in2exists) {}
bool is_bool_func() { return 1; }
void fix_length_and_dec() { decimals=0; max_length=1; }
uint decimal_precision() const { return 1; }
virtual bool created_by_in2exists() const { return m_created_by_in2exists; }
void set_created_by_in2exists() { m_created_by_in2exists= true; }
private:
/**
True <=> this item was added by IN->EXISTS subquery transformation, and
should thus be deleted if we switch to materialization.
*/
bool m_created_by_in2exists;
};
/**
Abstract Item class, to represent <code>X IS [NOT] (TRUE | FALSE)</code>
boolean predicates.
*/
class Item_func_truth : public Item_bool_func
{
public:
virtual bool val_bool();
virtual longlong val_int();
virtual void fix_length_and_dec();
virtual void print(String *str, enum_query_type query_type);
protected:
Item_func_truth(Item *a, bool a_value, bool a_affirmative)
: Item_bool_func(a), value(a_value), affirmative(a_affirmative)
{}
~Item_func_truth()
{}
private:
/**
True for <code>X IS [NOT] TRUE</code>,
false for <code>X IS [NOT] FALSE</code> predicates.
*/
const bool value;
/**
True for <code>X IS Y</code>, false for <code>X IS NOT Y</code> predicates.
*/
const bool affirmative;
};
/**
This Item represents a <code>X IS TRUE</code> boolean predicate.
*/
class Item_func_istrue : public Item_func_truth
{
public:
Item_func_istrue(Item *a) : Item_func_truth(a, true, true) {}
~Item_func_istrue() {}
virtual const char* func_name() const { return "istrue"; }
};
/**
This Item represents a <code>X IS NOT TRUE</code> boolean predicate.
*/
class Item_func_isnottrue : public Item_func_truth
{
public:
Item_func_isnottrue(Item *a) : Item_func_truth(a, true, false) {}
~Item_func_isnottrue() {}
virtual const char* func_name() const { return "isnottrue"; }
};
/**
This Item represents a <code>X IS FALSE</code> boolean predicate.
*/
class Item_func_isfalse : public Item_func_truth
{
public:
Item_func_isfalse(Item *a) : Item_func_truth(a, false, true) {}
~Item_func_isfalse() {}
virtual const char* func_name() const { return "isfalse"; }
};
/**
This Item represents a <code>X IS NOT FALSE</code> boolean predicate.
*/
class Item_func_isnotfalse : public Item_func_truth
{
public:
Item_func_isnotfalse(Item *a) : Item_func_truth(a, false, false) {}
~Item_func_isnotfalse() {}
virtual const char* func_name() const { return "isnotfalse"; }
};
class Item_cache;
#define UNKNOWN ((my_bool)-1)
/*
Item_in_optimizer(left_expr, Item_in_subselect(...))
Item_in_optimizer is used to wrap an instance of Item_in_subselect. This
class does the following:
- Evaluate the left expression and store it in Item_cache_* object (to
avoid re-evaluating it many times during subquery execution)
- Shortcut the evaluation of "NULL IN (...)" to NULL in the cases where we
don't care if the result is NULL or FALSE.
args[1] keeps a reference to the Item_in_subselect object.
args[0] is a copy of Item_in_subselect's left expression and should be
kept equal also after resolving.
NOTE
It is not quite clear why the above listed functionality should be
placed into a separate class called 'Item_in_optimizer'.
*/
class Item_in_optimizer: public Item_bool_func
{
private:
Item_cache *cache;
bool save_cache;
/*
Stores the value of "NULL IN (SELECT ...)" for uncorrelated subqueries:
UNKNOWN - "NULL in (SELECT ...)" has not yet been evaluated
FALSE - result is FALSE
TRUE - result is NULL
*/
my_bool result_for_null_param;
public:
Item_in_optimizer(Item *a, Item_in_subselect *b):
Item_bool_func(a, reinterpret_cast<Item *>(b)), cache(0),
save_cache(0), result_for_null_param(UNKNOWN)
{ with_subselect= TRUE; }
bool fix_fields(THD *, Item **);
bool fix_left(THD *thd, Item **ref);
void fix_after_pullout(st_select_lex *parent_select,
st_select_lex *removed_select);
bool is_null();
longlong val_int();
void cleanup();
const char *func_name() const { return "<in_optimizer>"; }
Item_cache **get_cache() { return &cache; }
void keep_top_level_cache();
Item *transform(Item_transformer transformer, uchar *arg);
};
class Comp_creator
{
public:
Comp_creator() {} /* Remove gcc warning */
virtual ~Comp_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const = 0;
virtual const char* symbol(bool invert) const = 0;
virtual bool eqne_op() const = 0;
virtual bool l_op() const = 0;
};
class Eq_creator :public Comp_creator
{
public:
Eq_creator() {} /* Remove gcc warning */
virtual ~Eq_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? "<>" : "="; }
virtual bool eqne_op() const { return 1; }
virtual bool l_op() const { return 0; }
};
class Ne_creator :public Comp_creator
{
public:
Ne_creator() {} /* Remove gcc warning */
virtual ~Ne_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? "=" : "<>"; }
virtual bool eqne_op() const { return 1; }
virtual bool l_op() const { return 0; }
};
class Gt_creator :public Comp_creator
{
public:
Gt_creator() {} /* Remove gcc warning */
virtual ~Gt_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? "<=" : ">"; }
virtual bool eqne_op() const { return 0; }
virtual bool l_op() const { return 0; }
};
class Lt_creator :public Comp_creator
{
public:
Lt_creator() {} /* Remove gcc warning */
virtual ~Lt_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? ">=" : "<"; }
virtual bool eqne_op() const { return 0; }
virtual bool l_op() const { return 1; }
};
class Ge_creator :public Comp_creator
{
public:
Ge_creator() {} /* Remove gcc warning */
virtual ~Ge_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? "<" : ">="; }
virtual bool eqne_op() const { return 0; }
virtual bool l_op() const { return 0; }
};
class Le_creator :public Comp_creator
{
public:
Le_creator() {} /* Remove gcc warning */
virtual ~Le_creator() {} /* Remove gcc warning */
virtual Item_bool_func2* create(Item *a, Item *b) const;
virtual const char* symbol(bool invert) const { return invert? ">" : "<="; }
virtual bool eqne_op() const { return 0; }
virtual bool l_op() const { return 1; }
};
class Item_bool_func2 :public Item_bool_func
{ /* Bool with 2 string args */
private:
bool convert_constant_arg(THD *thd, Item *field, Item **item);
protected:
Arg_comparator cmp;
bool abort_on_null;
public:
Item_bool_func2(Item *a,Item *b)
:Item_bool_func(a,b), cmp(tmp_arg, tmp_arg+1), abort_on_null(FALSE) {}
void fix_length_and_dec();
int set_cmp_func()
{
return cmp.set_cmp_func(this, tmp_arg, tmp_arg+1, TRUE);
}
optimize_type select_optimize() const { return OPTIMIZE_OP; }
virtual enum Functype rev_functype() const { return UNKNOWN_FUNC; }
bool have_rev_func() const { return rev_functype() != UNKNOWN_FUNC; }
virtual inline void print(String *str, enum_query_type query_type)
{
Item_func::print_op(str, query_type);
}
bool is_null() { return MY_TEST(args[0]->is_null() || args[1]->is_null()); }
const CHARSET_INFO *compare_collation()
{ return cmp.cmp_collation.collation; }
void top_level_item() { abort_on_null= TRUE; }
void cleanup()
{
Item_bool_func::cleanup();
cmp.cleanup();
}
friend class Arg_comparator;
};
class Item_bool_rowready_func2 :public Item_bool_func2
{
public:
Item_bool_rowready_func2(Item *a, Item *b) :Item_bool_func2(a, b)
{
allowed_arg_cols= 0; // Fetch this value from first argument
}
Item *neg_transformer(THD *thd);
virtual Item *negated_item();
bool subst_argument_checker(uchar **arg) { return TRUE; }
};
/**
XOR inherits from Item_bool_func2 because it is not optimized yet.
Later, when XOR is optimized, it needs to inherit from
Item_cond instead. See WL#5800.
*/
class Item_func_xor :public Item_bool_func2
{
public:
Item_func_xor(Item *i1, Item *i2) :Item_bool_func2(i1, i2) {}
enum Functype functype() const { return XOR_FUNC; }
const char *func_name() const { return "xor"; }
longlong val_int();
void top_level_item() {}
Item *neg_transformer(THD *thd);
};
class Item_func_not :public Item_bool_func
{
public:
Item_func_not(Item *a) :Item_bool_func(a) {}
longlong val_int();
enum Functype functype() const { return NOT_FUNC; }
const char *func_name() const { return "not"; }
Item *neg_transformer(THD *thd);
virtual void print(String *str, enum_query_type query_type);
};
class Item_maxmin_subselect;
struct st_join_table;
/*
trigcond<param>(arg) ::= param? arg : TRUE
The class Item_func_trig_cond is used for guarded predicates
which are employed only for internal purposes.
A guarded predicate is an object consisting of an a regular or
a guarded predicate P and a pointer to a boolean guard variable g.
A guarded predicate P/g is evaluated to true if the value of the
guard g is false, otherwise it is evaluated to the same value that
the predicate P: val(P/g)= g ? val(P):true.
Guarded predicates allow us to include predicates into a conjunction
conditionally. Currently they are utilized for pushed down predicates
in queries with outer join operations.
In the future, probably, it makes sense to extend this class to
the objects consisting of three elements: a predicate P, a pointer
to a variable g and a firing value s with following evaluation
rule: val(P/g,s)= g==s? val(P) : true. It will allow us to build only
one item for the objects of the form P/g1/g2...
Objects of this class are built only for query execution after
the execution plan has been already selected. That's why this
class needs only val_int out of generic methods.
Current uses of Item_func_trig_cond objects:
- To wrap selection conditions when executing outer joins
- To wrap condition that is pushed down into subquery
*/
class Item_func_trig_cond: public Item_bool_func
{
public:
enum enum_trig_type
{
/**
In t1 LEFT JOIN t2, ON can be tested on t2's row only if that row is
not NULL-complemented
*/
IS_NOT_NULL_COMPL,
/**
In t1 LEFT JOIN t2, the WHERE pushed to t2 can be tested only after at
least one t2's row has been found
*/
FOUND_MATCH,
/**
In IN->EXISTS subquery transformation, new predicates are added:
WHERE inner_field=outer_field OR inner_field IS NULL,
as well as
HAVING inner_field IS NOT NULL,
are disabled if outer_field is a NULL value
*/
OUTER_FIELD_IS_NOT_NULL
};
private:
/** Pointer to trigger variable */
bool *trig_var;
/** Optional table(s) which are the source of trig_var; for printing */
const struct st_join_table *trig_tab;
/** Type of trig_var; for printing */
enum_trig_type trig_type;
public:
/**
@param a the item for <condition>
@param f pointer to trigger variable
@param tab optional table which is source of 'f',
NULL if not applicable
@param trig_type_arg type of 'f'
*/
Item_func_trig_cond(Item *a, bool *f, struct st_join_table *tab,
enum_trig_type trig_type_arg)
: Item_bool_func(a), trig_var(f), trig_tab(tab), trig_type(trig_type_arg)
{}
longlong val_int() { return *trig_var ? args[0]->val_int() : 1; }
enum Functype functype() const { return TRIG_COND_FUNC; };
/// '<if>', to distinguish from the if() SQL function
const char *func_name() const { return "<if>"; };
bool const_item() const { return FALSE; }
bool *get_trig_var() { return trig_var; }
/* The following is needed for ICP: */
table_map used_tables() const { return args[0]->used_tables(); }
void print(String *str, enum_query_type query_type);
};
class Item_func_not_all :public Item_func_not
{
/* allow to check presence of values in max/min optimization */
Item_sum_hybrid *test_sum_item;
Item_maxmin_subselect *test_sub_item;
Item_subselect *subselect;
bool abort_on_null;
public:
bool show;
Item_func_not_all(Item *a)
:Item_func_not(a), test_sum_item(0), test_sub_item(0), subselect(0),
abort_on_null(0), show(0)
{}
virtual void top_level_item() { abort_on_null= 1; }
bool top_level() { return abort_on_null; }
longlong val_int();
enum Functype functype() const { return NOT_ALL_FUNC; }
const char *func_name() const { return "<not>"; }
virtual void print(String *str, enum_query_type query_type);
void set_sum_test(Item_sum_hybrid *item) { test_sum_item= item; };
void set_sub_test(Item_maxmin_subselect *item) { test_sub_item= item; };
void set_subselect(Item_subselect *item) { subselect= item; }
table_map not_null_tables() const
{
/*
See handling of not_null_tables_cache in
Item_in_optimizer::fix_fields().
This item is the result of a transformation from an ALL clause
such as
left-expr < ALL(subquery)
into
<not>(left-expr >= (subquery)
An inequality usually rejects NULLs from both operands, so the
not_null_tables() of the inequality is the union of the
null-rejecting tables of both operands. However, since this is a
transformed ALL clause that should return true if the subquery
is empty (even if left-expr is NULL), it is not null rejecting
for left-expr. The not null tables mask for left-expr should be
removed, leaving only the null-rejecting tables of the
subquery. Item_subselect::not_null_tables() always returns 0 (no
null-rejecting tables). Therefore, always return 0.
*/
return 0;
}
bool empty_underlying_subquery();
Item *neg_transformer(THD *thd);
};
class Item_func_nop_all :public Item_func_not_all
{
public:
Item_func_nop_all(Item *a) :Item_func_not_all(a) {}
longlong val_int();
const char *func_name() const { return "<nop>"; }
table_map not_null_tables() const { return not_null_tables_cache; }
Item *neg_transformer(THD *thd);
};
class Item_func_eq :public Item_bool_rowready_func2
{
public:
Item_func_eq(Item *a,Item *b) :
Item_bool_rowready_func2(a,b)
{}
longlong val_int();
enum Functype functype() const { return EQ_FUNC; }
enum Functype rev_functype() const { return EQ_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return "="; }
Item *negated_item();
virtual bool equality_substitution_analyzer(uchar **arg) { return true; }
virtual Item* equality_substitution_transformer(uchar *arg);
};
class Item_func_equal :public Item_bool_rowready_func2
{
public:
Item_func_equal(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {};
longlong val_int();
void fix_length_and_dec();
table_map not_null_tables() const { return 0; }
enum Functype functype() const { return EQUAL_FUNC; }
enum Functype rev_functype() const { return EQUAL_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return "<=>"; }
Item *neg_transformer(THD *thd) { return 0; }
};
class Item_func_ge :public Item_bool_rowready_func2
{
public:
Item_func_ge(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {};
longlong val_int();
enum Functype functype() const { return GE_FUNC; }
enum Functype rev_functype() const { return LE_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return ">="; }
Item *negated_item();
};
class Item_func_gt :public Item_bool_rowready_func2
{
public:
Item_func_gt(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {};
longlong val_int();
enum Functype functype() const { return GT_FUNC; }
enum Functype rev_functype() const { return LT_FUNC; }
cond_result eq_cmp_result() const { return COND_FALSE; }
const char *func_name() const { return ">"; }
Item *negated_item();
};
class Item_func_le :public Item_bool_rowready_func2
{
public:
Item_func_le(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {};
longlong val_int();
enum Functype functype() const { return LE_FUNC; }
enum Functype rev_functype() const { return GE_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return "<="; }
Item *negated_item();
};
class Item_func_lt :public Item_bool_rowready_func2
{
public:
Item_func_lt(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {}
longlong val_int();
enum Functype functype() const { return LT_FUNC; }
enum Functype rev_functype() const { return GT_FUNC; }
cond_result eq_cmp_result() const { return COND_FALSE; }
const char *func_name() const { return "<"; }
Item *negated_item();
};
class Item_func_ne :public Item_bool_rowready_func2
{
public:
Item_func_ne(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {}
longlong val_int();
enum Functype functype() const { return NE_FUNC; }
cond_result eq_cmp_result() const { return COND_FALSE; }
optimize_type select_optimize() const { return OPTIMIZE_KEY; }
const char *func_name() const { return "<>"; }
Item *negated_item();
};
/*
The class Item_func_opt_neg is defined to factor out the functionality
common for the classes Item_func_between and Item_func_in. The objects
of these classes can express predicates or there negations.
The alternative approach would be to create pairs Item_func_between,
Item_func_notbetween and Item_func_in, Item_func_notin.
*/
class Item_func_opt_neg :public Item_int_func
{
public:
bool negated; /* <=> the item represents NOT <func> */
bool pred_level; /* <=> [NOT] <func> is used on a predicate level */
public:
Item_func_opt_neg(Item *a, Item *b, Item *c)
:Item_int_func(a, b, c), negated(0), pred_level(0) {}
Item_func_opt_neg(List<Item> &list)
:Item_int_func(list), negated(0), pred_level(0) {}
public:
inline void negate() { negated= !negated; }
inline void top_level_item() { pred_level= 1; }
Item *neg_transformer(THD *thd)
{
negated= !negated;
return this;
}
bool eq(const Item *item, bool binary_cmp) const;
bool subst_argument_checker(uchar **arg) { return TRUE; }
};
class Item_func_between :public Item_func_opt_neg
{
DTCollation cmp_collation;
public:
Item_result cmp_type;
String value0,value1,value2;
/* TRUE <=> arguments will be compared as dates. */
bool compare_as_dates_with_strings;
bool compare_as_temporal_dates;
bool compare_as_temporal_times;
/* Comparators used for DATE/DATETIME comparison. */
Arg_comparator ge_cmp, le_cmp;
Item_func_between(Item *a, Item *b, Item *c)
:Item_func_opt_neg(a, b, c), compare_as_dates_with_strings(FALSE),
compare_as_temporal_dates(FALSE),
compare_as_temporal_times(FALSE) {}
longlong val_int();
optimize_type select_optimize() const { return OPTIMIZE_KEY; }
enum Functype functype() const { return BETWEEN; }
const char *func_name() const { return "between"; }
bool fix_fields(THD *, Item **);
void fix_after_pullout(st_select_lex *parent_select,
st_select_lex *removed_select);
void fix_length_and_dec();
virtual void print(String *str, enum_query_type query_type);
bool is_bool_func() { return 1; }
const CHARSET_INFO *compare_collation() { return cmp_collation.collation; }
uint decimal_precision() const { return 1; }
};
class Item_func_strcmp :public Item_bool_func2
{
public:
Item_func_strcmp(Item *a,Item *b) :Item_bool_func2(a,b) {}
longlong val_int();
optimize_type select_optimize() const { return OPTIMIZE_NONE; }
const char *func_name() const { return "strcmp"; }
virtual inline void print(String *str, enum_query_type query_type)
{
Item_func::print(str, query_type);
}
void fix_length_and_dec()
{
Item_bool_func2::fix_length_and_dec();
fix_char_length(2); // returns "1" or "0" or "-1"
}
};
struct interval_range
{
Item_result type;
double dbl;
my_decimal dec;
};
class Item_func_interval :public Item_int_func
{
Item_row *row;
my_bool use_decimal_comparison;
interval_range *intervals;
public:
Item_func_interval(Item_row *a)
:Item_int_func(a),row(a),intervals(0)
{
allowed_arg_cols= 0; // Fetch this value from first argument
}
longlong val_int();
void fix_length_and_dec();
const char *func_name() const { return "interval"; }
uint decimal_precision() const { return 2; }
};
class Item_func_coalesce :public Item_func_numhybrid
{
protected:
enum_field_types cached_field_type;
Item_func_coalesce(Item *a, Item *b) :Item_func_numhybrid(a, b) {}
public:
Item_func_coalesce(List<Item> &list) :Item_func_numhybrid(list) {}
double real_op();
longlong int_op();
String *str_op(String *);
bool date_op(MYSQL_TIME *ltime, uint fuzzydate);
bool time_op(MYSQL_TIME *ltime);
my_decimal *decimal_op(my_decimal *);
void fix_length_and_dec();
void find_num_type() {}
enum Item_result result_type () const { return hybrid_type; }
const char *func_name() const { return "coalesce"; }
table_map not_null_tables() const { return 0; }
enum_field_types field_type() const { return cached_field_type; }
};
class Item_func_ifnull :public Item_func_coalesce
{
protected:
bool field_type_defined;
public:
Item_func_ifnull(Item *a, Item *b) :Item_func_coalesce(a,b) {}
double real_op();
longlong int_op();
String *str_op(String *str);
bool date_op(MYSQL_TIME *ltime, uint fuzzydate);
bool time_op(MYSQL_TIME *ltime);
my_decimal *decimal_op(my_decimal *);
void fix_length_and_dec();
const char *func_name() const { return "ifnull"; }
Field *tmp_table_field(TABLE *table);
uint decimal_precision() const;
};
class Item_func_if :public Item_func
{
enum Item_result cached_result_type;
enum_field_types cached_field_type;
public:
Item_func_if(Item *a,Item *b,Item *c)
:Item_func(a,b,c), cached_result_type(INT_RESULT)
{}
double val_real();
longlong val_int();
String *val_str(String *str);
my_decimal *val_decimal(my_decimal *);
bool get_date(MYSQL_TIME *ltime, uint fuzzydate);
bool get_time(MYSQL_TIME *ltime);
enum Item_result result_type () const { return cached_result_type; }
enum_field_types field_type() const { return cached_field_type; }
bool fix_fields(THD *, Item **);
void fix_length_and_dec();
void fix_after_pullout(st_select_lex *parent_select,
st_select_lex *removed_select);
uint decimal_precision() const;
const char *func_name() const { return "if"; }
private:
void cache_type_info(Item *source);
};
class Item_func_nullif :public Item_bool_func2
{
enum Item_result cached_result_type;
public:
Item_func_nullif(Item *a,Item *b)
:Item_bool_func2(a,b), cached_result_type(INT_RESULT)
{}
double val_real();
longlong val_int();
String *val_str(String *str);
my_decimal *val_decimal(my_decimal *);
enum Item_result result_type () const { return cached_result_type; }
void fix_length_and_dec();
uint decimal_precision() const { return args[0]->decimal_precision(); }
const char *func_name() const { return "nullif"; }
virtual inline void print(String *str, enum_query_type query_type)
{
Item_func::print(str, query_type);
}
table_map not_null_tables() const { return 0; }
bool is_null();
};
/* Functions to handle the optimized IN */
/* A vector of values of some type */
class in_vector :public Sql_alloc
{
public:
char *base;
uint size;
qsort2_cmp compare;
const CHARSET_INFO *collation;
uint count;
uint used_count;
in_vector() {}
in_vector(uint elements,uint element_length,qsort2_cmp cmp_func,
const CHARSET_INFO *cmp_coll)
:base((char*) sql_calloc(elements*element_length)),
size(element_length), compare(cmp_func), collation(cmp_coll),
count(elements), used_count(elements) {}
virtual ~in_vector() {}
virtual void set(uint pos,Item *item)=0;
virtual uchar *get_value(Item *item)=0;
void sort()
{
my_qsort2(base,used_count,size,compare,collation);
}
int find(Item *item);
/*
Create an instance of Item_{type} (e.g. Item_decimal) constant object
which type allows it to hold an element of this vector without any
conversions.
The purpose of this function is to be able to get elements of this
vector in form of Item_xxx constants without creating Item_xxx object
for every array element you get (i.e. this implements "FlyWeight" pattern)
*/
virtual Item* create_item() { return NULL; }
/*
Store the value at position #pos into provided item object
SYNOPSIS
value_to_item()
pos Index of value to store
item Constant item to store value into. The item must be of the same
type that create_item() returns.
*/
virtual void value_to_item(uint pos, Item *item) { }
/* Compare values number pos1 and pos2 for equality */
bool compare_elems(uint pos1, uint pos2)
{
return MY_TEST(compare(collation, base + pos1*size, base + pos2*size));
}
virtual Item_result result_type()= 0;
};
class in_string :public in_vector
{
char buff[STRING_BUFFER_USUAL_SIZE];
String tmp;
public:
in_string(uint elements,qsort2_cmp cmp_func, const CHARSET_INFO *cs);
~in_string();
void set(uint pos,Item *item);
uchar *get_value(Item *item);
Item* create_item()
{
return new Item_string(collation);
}
void value_to_item(uint pos, Item *item)
{
String *str=((String*) base)+pos;
Item_string *to= (Item_string*)item;
to->str_value= *str;
}
Item_result result_type() { return STRING_RESULT; }
};
class in_longlong :public in_vector
{
protected:
/*
Here we declare a temporary variable (tmp) of the same type as the
elements of this vector. tmp is used in finding if a given value is in
the list.
*/
struct packed_longlong
{
longlong val;
longlong unsigned_flag; // Use longlong, not bool, to preserve alignment
} tmp;
public:
in_longlong(uint elements);
void set(uint pos,Item *item);
uchar *get_value(Item *item);