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/* Copyright (C) 2000-2003 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* This file defines all string functions */
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#ifdef USE_PRAGMA_INTERFACE
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#pragma interface /* gcc class implementation */
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class Item_str_func :public Item_func
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Item_str_func() :Item_func() { decimals=NOT_FIXED_DEC; }
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Item_str_func(Item *a) :Item_func(a) {decimals=NOT_FIXED_DEC; }
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Item_str_func(Item *a,Item *b) :Item_func(a,b) { decimals=NOT_FIXED_DEC; }
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Item_str_func(Item *a,Item *b,Item *c) :Item_func(a,b,c) { decimals=NOT_FIXED_DEC; }
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Item_str_func(Item *a,Item *b,Item *c,Item *d) :Item_func(a,b,c,d) {decimals=NOT_FIXED_DEC; }
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Item_str_func(Item *a,Item *b,Item *c,Item *d, Item* e) :Item_func(a,b,c,d,e) {decimals=NOT_FIXED_DEC; }
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Item_str_func(List<Item> &list) :Item_func(list) {decimals=NOT_FIXED_DEC; }
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my_decimal *val_decimal(my_decimal *);
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enum Item_result result_type () const { return STRING_RESULT; }
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void left_right_max_length();
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bool fix_fields(THD *thd, Item **ref);
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class Item_func_concat :public Item_str_func
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Item_func_concat(List<Item> &list) :Item_str_func(list) {}
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Item_func_concat(Item *a,Item *b) :Item_str_func(a,b) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "concat"; }
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class Item_func_concat_ws :public Item_str_func
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Item_func_concat_ws(List<Item> &list) :Item_str_func(list) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "concat_ws"; }
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table_map not_null_tables() const { return 0; }
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class Item_func_reverse :public Item_str_func
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Item_func_reverse(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "reverse"; }
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class Item_func_replace :public Item_str_func
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String tmp_value,tmp_value2;
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Item_func_replace(Item *org,Item *find,Item *replace)
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:Item_str_func(org,find,replace) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "replace"; }
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class Item_func_insert :public Item_str_func
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Item_func_insert(Item *org,Item *start,Item *length,Item *new_str)
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:Item_str_func(org,start,length,new_str) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "insert"; }
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class Item_str_conv :public Item_str_func
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my_charset_conv_case converter;
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Item_str_conv(Item *item) :Item_str_func(item) {}
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String *val_str(String *);
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class Item_func_lcase :public Item_str_conv
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Item_func_lcase(Item *item) :Item_str_conv(item) {}
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const char *func_name() const { return "lcase"; }
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void fix_length_and_dec();
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class Item_func_ucase :public Item_str_conv
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Item_func_ucase(Item *item) :Item_str_conv(item) {}
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const char *func_name() const { return "ucase"; }
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void fix_length_and_dec();
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class Item_func_left :public Item_str_func
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Item_func_left(Item *a,Item *b) :Item_str_func(a,b) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "left"; }
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class Item_func_right :public Item_str_func
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Item_func_right(Item *a,Item *b) :Item_str_func(a,b) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "right"; }
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class Item_func_substr :public Item_str_func
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Item_func_substr(Item *a,Item *b) :Item_str_func(a,b) {}
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Item_func_substr(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "substr"; }
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class Item_func_substr_index :public Item_str_func
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Item_func_substr_index(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "substring_index"; }
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class Item_func_trim :public Item_str_func
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Item_func_trim(Item *a,Item *b) :Item_str_func(a,b) {}
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Item_func_trim(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "trim"; }
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virtual void print(String *str, enum_query_type query_type);
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virtual const char *mode_name() const { return "both"; }
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class Item_func_ltrim :public Item_func_trim
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Item_func_ltrim(Item *a,Item *b) :Item_func_trim(a,b) {}
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Item_func_ltrim(Item *a) :Item_func_trim(a) {}
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String *val_str(String *);
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const char *func_name() const { return "ltrim"; }
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const char *mode_name() const { return "leading"; }
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class Item_func_rtrim :public Item_func_trim
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Item_func_rtrim(Item *a,Item *b) :Item_func_trim(a,b) {}
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Item_func_rtrim(Item *a) :Item_func_trim(a) {}
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String *val_str(String *);
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const char *func_name() const { return "rtrim"; }
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const char *mode_name() const { return "trailing"; }
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class Item_func_sysconst :public Item_str_func
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{ collation.set(system_charset_info,DERIVATION_SYSCONST); }
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Item *safe_charset_converter(const CHARSET_INFO * const tocs);
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Used to create correct Item name in new converted item in
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safe_charset_converter, return string representation of this function
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virtual const char *fully_qualified_func_name() const = 0;
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class Item_func_database :public Item_func_sysconst
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Item_func_database() :Item_func_sysconst() {}
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String *val_str(String *);
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void fix_length_and_dec()
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max_length= MAX_FIELD_NAME * system_charset_info->mbmaxlen;
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const char *func_name() const { return "database"; }
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const char *fully_qualified_func_name() const { return "database()"; }
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class Item_func_user :public Item_func_sysconst
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bool init (const char *user, const char *host);
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str_value.set("", 0, system_charset_info);
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String *val_str(String *)
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return (null_value ? 0 : &str_value);
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bool fix_fields(THD *thd, Item **ref);
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void fix_length_and_dec()
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max_length= (USERNAME_CHAR_LENGTH + HOSTNAME_LENGTH + 1) *
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system_charset_info->mbmaxlen;
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const char *func_name() const { return "user"; }
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const char *fully_qualified_func_name() const { return "user()"; }
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int save_in_field(Field *field,
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bool no_conversions __attribute__((unused)))
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return save_str_value_in_field(field, &str_value);
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class Item_func_current_user :public Item_func_user
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Name_resolution_context *context;
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Item_func_current_user(Name_resolution_context *context_arg)
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: context(context_arg) {}
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bool fix_fields(THD *thd, Item **ref);
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const char *func_name() const { return "current_user"; }
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const char *fully_qualified_func_name() const { return "current_user()"; }
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class Item_func_soundex :public Item_str_func
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Item_func_soundex(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "soundex"; }
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class Item_func_elt :public Item_str_func
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Item_func_elt(List<Item> &list) :Item_str_func(list) {}
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String *val_str(String *str);
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void fix_length_and_dec();
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const char *func_name() const { return "elt"; }
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class Item_func_make_set :public Item_str_func
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Item_func_make_set(Item *a,List<Item> &list) :Item_str_func(list),item(a) {}
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String *val_str(String *str);
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bool fix_fields(THD *thd, Item **ref)
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return ((!item->fixed && item->fix_fields(thd, &item)) ||
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item->check_cols(1) ||
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Item_func::fix_fields(thd, ref));
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void split_sum_func(THD *thd, Item **ref_pointer_array, List<Item> &fields);
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void fix_length_and_dec();
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void update_used_tables();
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const char *func_name() const { return "make_set"; }
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bool walk(Item_processor processor, bool walk_subquery, uchar *arg)
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return item->walk(processor, walk_subquery, arg) ||
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Item_str_func::walk(processor, walk_subquery, arg);
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Item *transform(Item_transformer transformer, uchar *arg);
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virtual void print(String *str, enum_query_type query_type);
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class Item_func_format :public Item_str_func
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Item_func_format(Item *org, Item *dec);
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "format"; }
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virtual void print(String *str, enum_query_type query_type);
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class Item_func_char :public Item_str_func
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Item_func_char(List<Item> &list) :Item_str_func(list)
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{ collation.set(&my_charset_bin); }
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Item_func_char(List<Item> &list, const CHARSET_INFO * const cs) :Item_str_func(list)
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{ collation.set(cs); }
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String *val_str(String *);
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void fix_length_and_dec()
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max_length= arg_count * 4;
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const char *func_name() const { return "char"; }
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class Item_func_repeat :public Item_str_func
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Item_func_repeat(Item *arg1,Item *arg2) :Item_str_func(arg1,arg2) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "repeat"; }
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class Item_func_rpad :public Item_str_func
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String tmp_value, rpad_str;
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Item_func_rpad(Item *arg1,Item *arg2,Item *arg3)
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:Item_str_func(arg1,arg2,arg3) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "rpad"; }
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class Item_func_lpad :public Item_str_func
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String tmp_value, lpad_str;
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Item_func_lpad(Item *arg1,Item *arg2,Item *arg3)
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:Item_str_func(arg1,arg2,arg3) {}
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "lpad"; }
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class Item_func_conv :public Item_str_func
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Item_func_conv(Item *a,Item *b,Item *c) :Item_str_func(a,b,c) {}
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const char *func_name() const { return "conv"; }
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String *val_str(String *);
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void fix_length_and_dec()
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collation.set(default_charset());
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class Item_func_hex :public Item_str_func
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Item_func_hex(Item *a) :Item_str_func(a) {}
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const char *func_name() const { return "hex"; }
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String *val_str(String *);
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void fix_length_and_dec()
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collation.set(default_charset());
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max_length=args[0]->max_length*2*collation.collation->mbmaxlen;
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class Item_func_unhex :public Item_str_func
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Item_func_unhex(Item *a) :Item_str_func(a)
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/* there can be bad hex strings */
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const char *func_name() const { return "unhex"; }
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String *val_str(String *);
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void fix_length_and_dec()
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collation.set(&my_charset_bin);
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max_length=(1+args[0]->max_length)/2;
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class Item_func_binary :public Item_str_func
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Item_func_binary(Item *a) :Item_str_func(a) {}
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String *val_str(String *a)
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String *tmp=args[0]->val_str(a);
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null_value=args[0]->null_value;
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tmp->set_charset(&my_charset_bin);
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void fix_length_and_dec()
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collation.set(&my_charset_bin);
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max_length=args[0]->max_length;
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virtual void print(String *str, enum_query_type query_type);
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const char *func_name() const { return "cast_as_binary"; }
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class Item_load_file :public Item_str_func
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Item_load_file(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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const char *func_name() const { return "load_file"; }
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void fix_length_and_dec()
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collation.set(&my_charset_bin, DERIVATION_COERCIBLE);
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max_length=MAX_BLOB_WIDTH;
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class Item_func_export_set: public Item_str_func
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Item_func_export_set(Item *a,Item *b,Item* c) :Item_str_func(a,b,c) {}
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Item_func_export_set(Item *a,Item *b,Item* c,Item* d) :Item_str_func(a,b,c,d) {}
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Item_func_export_set(Item *a,Item *b,Item* c,Item* d,Item* e) :Item_str_func(a,b,c,d,e) {}
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String *val_str(String *str);
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void fix_length_and_dec();
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const char *func_name() const { return "export_set"; }
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class Item_func_quote :public Item_str_func
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Item_func_quote(Item *a) :Item_str_func(a) {}
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const char *func_name() const { return "quote"; }
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String *val_str(String *);
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void fix_length_and_dec()
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collation.set(args[0]->collation);
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max_length= args[0]->max_length * 2 + 2;
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class Item_func_conv_charset :public Item_str_func
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bool use_cached_value;
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const CHARSET_INFO *conv_charset; // keep it public
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Item_func_conv_charset(Item *a, const CHARSET_INFO * const cs) :Item_str_func(a)
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{ conv_charset= cs; use_cached_value= 0; safe= 0; }
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Item_func_conv_charset(Item *a, const CHARSET_INFO * const cs, bool cache_if_const)
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assert(args[0]->fixed);
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if (cache_if_const && args[0]->const_item())
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String tmp, *str= args[0]->val_str(&tmp);
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if (!str || str_value.copy(str->ptr(), str->length(),
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str->charset(), conv_charset, &errors))
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str_value.mark_as_const();
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Conversion from and to "binary" is safe.
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Conversion to Unicode is safe.
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Other kind of conversions are potentially lossy.
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safe= (args[0]->collation.collation == &my_charset_bin ||
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cs == &my_charset_bin ||
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(cs->state & MY_CS_UNICODE));
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String *val_str(String *);
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void fix_length_and_dec();
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const char *func_name() const { return "convert"; }
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virtual void print(String *str, enum_query_type query_type);
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class Item_func_set_collation :public Item_str_func
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Item_func_set_collation(Item *a, Item *b) :Item_str_func(a,b) {};
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String *val_str(String *);
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void fix_length_and_dec();
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bool eq(const Item *item, bool binary_cmp) const;
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const char *func_name() const { return "collate"; }
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enum Functype functype() const { return COLLATE_FUNC; }
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virtual void print(String *str, enum_query_type query_type);
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Item_field *filed_for_view_update()
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/* this function is transparent for view updating */
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return args[0]->filed_for_view_update();
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class Item_func_charset :public Item_str_func
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Item_func_charset(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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const char *func_name() const { return "charset"; }
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void fix_length_and_dec()
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collation.set(system_charset_info);
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max_length= 64 * collation.collation->mbmaxlen; // should be enough
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table_map not_null_tables() const { return 0; }
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class Item_func_collation :public Item_str_func
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Item_func_collation(Item *a) :Item_str_func(a) {}
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String *val_str(String *);
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const char *func_name() const { return "collation"; }
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void fix_length_and_dec()
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collation.set(system_charset_info);
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max_length= 64 * collation.collation->mbmaxlen; // should be enough
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table_map not_null_tables() const { return 0; }
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class Item_func_weight_string :public Item_str_func
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Item_func_weight_string(Item *a, uint nweights_arg, uint flags_arg)
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:Item_str_func(a) { nweights= nweights_arg; flags= flags_arg; }
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const char *func_name() const { return "weight_string"; }
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String *val_str(String *);
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void fix_length_and_dec();
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class Item_func_uncompressed_length : public Item_int_func
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Item_func_uncompressed_length(Item *a):Item_int_func(a){}
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const char *func_name() const{return "uncompressed_length";}
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void fix_length_and_dec() { max_length=10; }
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#define ZLIB_DEPENDED_FUNCTION ;
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#define ZLIB_DEPENDED_FUNCTION { null_value=1; return 0; }
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class Item_func_compress: public Item_str_func
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Item_func_compress(Item *a):Item_str_func(a){}
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void fix_length_and_dec(){max_length= (args[0]->max_length*120)/100+12;}
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const char *func_name() const{return "compress";}
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String *val_str(String *) ZLIB_DEPENDED_FUNCTION
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class Item_func_uncompress: public Item_str_func
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Item_func_uncompress(Item *a): Item_str_func(a){}
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void fix_length_and_dec(){ maybe_null= 1; max_length= MAX_BLOB_WIDTH; }
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const char *func_name() const{return "uncompress";}
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String *val_str(String *) ZLIB_DEPENDED_FUNCTION
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#define UUID_LENGTH (8+1+4+1+4+1+4+1+12)
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class Item_func_uuid: public Item_str_func
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Item_func_uuid(): Item_str_func() {}
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void fix_length_and_dec() {
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collation.set(system_charset_info);
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NOTE! uuid() should be changed to use 'ascii'
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charset when hex(), format(), md5(), etc, and implicit
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number-to-string conversion will use 'ascii'
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max_length= UUID_LENGTH * system_charset_info->mbmaxlen;
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const char *func_name() const{ return "uuid"; }
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String *val_str(String *);