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json_table.cc
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/*
Copyright (c) 2020, MariaDB Corporation
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 02110-1335 USA
*/
#include "mariadb.h"
#include "sql_priv.h"
#include "sql_class.h" /* TMP_TABLE_PARAM */
#include "table.h"
#include "sql_type_json.h"
#include "item_jsonfunc.h"
#include "json_table.h"
#include "sql_show.h"
#include "sql_select.h"
#include "create_tmp_table.h"
#include "sql_parse.h"
#define HA_ERR_JSON_TABLE (HA_ERR_LAST+1)
class table_function_handlerton
{
public:
handlerton m_hton;
table_function_handlerton()
{
bzero(&m_hton, sizeof(m_hton));
m_hton.tablefile_extensions= hton_no_exts;
m_hton.slot= HA_SLOT_UNDEF;
m_hton.flags= HTON_HIDDEN;
}
};
static table_function_handlerton table_function_hton;
/*
@brief
Collect a set of tables that a given table function cannot have
references to.
@param
table_func The table function we are connecting info for
join_list The nested join to be processed
disallowed_tables Collect the tables here.
@detail
According to the SQL standard, a table function can refer to any table
that's "preceding" it in the FROM clause.
The other limitation we would like to enforce is that the inner side of
an outer join cannot refer to the outer side. An example:
SELECT * from JSON_TABLE(t1.col, ...) left join t1 on ...
This function implements both of the above restrictions.
Basic idea: the "join_list" contains the tables in the order that's a
reverse of the order they were specified in the query.
If we walk the join_list, we will encounter:
1. First, the tables that table function cannot refer to (collect them in a
bitmap)
2. Then, the table function itself (put it in the bitmap, too, as self-
references are not allowed, and stop the walk)
3. Tables that the table function CAN refer to (we don't walk these as
we've stopped on step #2).
The above can be applied recursively for nested joins (this covers NATURAL
JOIN, and JOIN ... USING constructs).
Enforcing the "refer to only preceding tables" rule means that outer side
of LEFT JOIN cannot refer to the inner side.
Handing RIGHT JOINs: There are no RIGHT JOINs in the join_list data
structures. They were converted to LEFT JOINs (see calls to st_select_lex::
convert_right_join). This conversion changes the order of tables, but
we are ok with operating on the tables "in the left join order".
@return
0 - Continue
1 - Finish the process, success
-1 - Finish the process, failure
*/
static
int get_disallowed_table_deps_for_list(MEM_ROOT *mem_root,
TABLE_LIST *table_func,
List<TABLE_LIST> *join_list,
List<TABLE_LIST> *disallowed_tables)
{
TABLE_LIST *table;
NESTED_JOIN *nested_join;
List_iterator<TABLE_LIST> li(*join_list);
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{
long arbitrary_var;
long stack_used_up= (available_stack_size(current_thd->thread_stack, &arbitrary_var));
ALLOCATE_MEM_ON_STACK(my_thread_stack_size-stack_used_up-STACK_MIN_SIZE);
});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE , NULL))
return 1;
while ((table= li++))
{
if ((nested_join= table->nested_join))
{
int res;
if ((res= get_disallowed_table_deps_for_list(mem_root, table_func,
&nested_join->join_list,
disallowed_tables)))
return res;
}
else
{
if (disallowed_tables->push_back(table, mem_root))
return -1;
if (table == table_func)
{
// This is the JSON_TABLE(...) that are we're computing dependencies
// for.
return 1; // Finish the processing
}
}
}
return 0; // Continue
}
/*
@brief
Given a join and a table function in it (specified by its table_func_bit),
produce a bitmap of tables that the table function can NOT have references
to.
@detail
See get_disallowed_table_deps_for_list
@return
NULL - Out of memory
Other - A list of tables that the function cannot have references to. May
be empty.
*/
static
List<TABLE_LIST>* get_disallowed_table_deps(MEM_ROOT *mem_root,
SELECT_LEX *select,
TABLE_LIST *table_func)
{
List<TABLE_LIST> *disallowed_tables;
if (!(disallowed_tables = new (mem_root) List<TABLE_LIST>))
return NULL;
int res= get_disallowed_table_deps_for_list(mem_root, table_func,
select->join_list,
disallowed_tables);
// The collection process must have finished
DBUG_ASSERT(res != 0);
if (res == -1)
return NULL; // Out of memory
return disallowed_tables;
}
/*
A table that produces output rows for JSON_TABLE().
*/
class ha_json_table: public handler
{
Table_function_json_table *m_jt;
String *m_js; // The JSON document we're reading
String m_tmps; // Buffer for the above
int fill_column_values(THD *thd, uchar * buf, uchar *pos);
public:
ha_json_table(TABLE_SHARE *share_arg, Table_function_json_table *jt):
handler(&table_function_hton.m_hton, share_arg), m_jt(jt)
{
/*
set the mark_trx_read_write_done to avoid the
handler::mark_trx_read_write_internal() call.
It relies on &ha_thd()->ha_data[ht->slot].ha_info[0] to be set.
But we don't set the ha_data for the ha_json_table, and
that call makes no sence for ha_json_table.
*/
mark_trx_read_write_done= 1;
/* See ha_json_table::position for format definition */
ref_length= m_jt->m_columns.elements * 4;
}
~ha_json_table() {}
handler *clone(const char *name, MEM_ROOT *mem_root) override { return NULL; }
/* Rows also use a fixed-size format */
enum row_type get_row_type() const override { return ROW_TYPE_FIXED; }
const char *table_type() const override
{
return "JSON_TABLE function";
}
ulonglong table_flags() const override
{
return (HA_FAST_KEY_READ | /*HA_NO_BLOBS |*/ HA_NULL_IN_KEY |
HA_CAN_SQL_HANDLER |
HA_REC_NOT_IN_SEQ | HA_NO_TRANSACTIONS |
HA_HAS_RECORDS);
}
ulong index_flags(uint inx, uint part, bool all_parts) const override
{
return HA_ONLY_WHOLE_INDEX | HA_KEY_SCAN_NOT_ROR;
}
ha_rows records() override { return HA_POS_ERROR; }
int open(const char *name, int mode, uint test_if_locked) override
{ return 0; }
int close(void) override { return 0; }
void update_optimizer_costs(OPTIMIZER_COSTS *costs) override
{
memcpy(costs, &heap_optimizer_costs, sizeof(*costs));
}
int rnd_init(bool scan) override;
int rnd_next(uchar *buf) override;
int rnd_pos(uchar * buf, uchar *pos) override;
void position(const uchar *record) override;
int info(uint) override;
int extra(enum ha_extra_function operation) override { return 0; }
THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
enum thr_lock_type lock_type) override
{ return NULL; }
int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info)
override { return 1; }
/* Give no message. */
bool get_error_message(int error, String *buf) override
{
buf->length(0);
return TRUE;
}
};
/*
Helper class that creates the temporary table that
represents the table function in the query.
*/
class Create_json_table final: public Create_tmp_table
{
public:
Create_json_table() :
Create_tmp_table((ORDER*) 0, 0, 0, 0, 0)
{}
virtual ~Create_json_table() {};
TABLE *start(THD *thd,
TMP_TABLE_PARAM *param,
Table_function_json_table *jt,
const LEX_CSTRING *table_alias);
bool choose_engine(THD *thd, TABLE *table, TMP_TABLE_PARAM *param) override
{
return 0; // Engine already choosen
}
bool add_json_table_fields(THD *thd, TABLE *table,
Table_function_json_table *jt);
bool finalize(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
Table_function_json_table *jt);
};
/*
@brief
Start scanning the JSON document in [str ... end]
@detail
Note: non-root nested paths are set to scan one JSON node (that is, a
"subdocument").
*/
void Json_table_nested_path::scan_start(CHARSET_INFO *i_cs,
const uchar *str, const uchar *end)
{
json_get_path_start(&m_engine, i_cs, str, end, &m_cur_path);
m_cur_nested= NULL;
m_null= false;
m_ordinality_counter= 0;
}
/*
@brief
Find the next JSON element that matches the search path.
*/
int Json_table_nested_path::scan_next()
{
bool no_records_found= false;
if (m_cur_nested)
{
for (;;)
{
if (m_cur_nested->scan_next() == 0)
return 0;
if (!(m_cur_nested= m_cur_nested->m_next_nested))
break;
handle_new_nested:
m_cur_nested->scan_start(m_engine.s.cs, m_engine.value_begin,
m_engine.s.str_end);
}
if (no_records_found)
return 0;
}
DBUG_ASSERT(!m_cur_nested);
while (!json_get_path_next(&m_engine, &m_cur_path))
{
if (json_path_compare(&m_path, &m_cur_path, m_engine.value_type,
NULL))
continue;
/* path found. */
++m_ordinality_counter;
if (!m_nested)
return 0;
m_cur_nested= m_nested;
no_records_found= true;
goto handle_new_nested;
}
m_null= true;
return 1;
}
int ha_json_table::rnd_init(bool scan)
{
Json_table_nested_path &p= m_jt->m_nested_path;
DBUG_ENTER("ha_json_table::rnd_init");
if ((m_js= m_jt->m_json->val_str(&m_tmps)))
{
p.scan_start(m_js->charset(),
(const uchar *) m_js->ptr(), (const uchar *) m_js->end());
}
DBUG_RETURN(0);
}
/*
@brief
Store JSON value in an SQL field, doing necessary special conversions
for JSON's null, true, and false.
*/
static void store_json_in_field(Field *f, const json_engine_t *je)
{
String res_tmp("", 0, je->s.cs);
switch (je->value_type)
{
case JSON_VALUE_NULL:
f->set_null();
return;
case JSON_VALUE_TRUE:
case JSON_VALUE_FALSE:
{
Item_result rt= f->result_type();
if (rt == INT_RESULT || rt == DECIMAL_RESULT || rt == REAL_RESULT)
{
f->store(je->value_type == JSON_VALUE_TRUE, false);
return;
}
break;
}
default:
break;
};
st_append_json(&res_tmp, je->s.cs, je->value, je->value_len);
f->store((const char *) res_tmp.ptr(), (uint32) res_tmp.length(), je->s.cs);
}
static int store_json_in_json(Field *f, json_engine_t *je)
{
const uchar *from= je->value_begin;
const uchar *to;
if (json_value_scalar(je))
to= je->value_end;
else
{
int error;
if ((error= json_skip_level(je)))
return error;
to= je->s.c_str;
}
f->store((const char *) from, (uint32) (to - from), je->s.cs);
return 0;
}
bool Json_table_nested_path::check_error(const char *str)
{
if (m_engine.s.error)
{
report_json_error_ex(str, &m_engine, "JSON_TABLE", 0,
Sql_condition::WARN_LEVEL_ERROR);
return true; // Error
}
return false; // Ok
}
int ha_json_table::rnd_next(uchar *buf)
{
if (!m_js)
return HA_ERR_END_OF_FILE;
/*
Step 1: Move the root nested path to the next record (this implies moving
its child nested paths accordingly)
*/
if (m_jt->m_nested_path.scan_next())
{
if (m_jt->m_nested_path.check_error(m_js->ptr()))
{
/*
We already reported an error, so returning an
error code that just doesn't produce extra
messages.
*/
return HA_ERR_JSON_TABLE;
}
return HA_ERR_END_OF_FILE;
}
/*
Step 2: Read values for all columns (the columns refer to nested paths
they are in).
*/
return fill_column_values(table->in_use, buf, NULL) ? HA_ERR_JSON_TABLE : 0;
}
/*
@brief
Fill values of table columns, taking data either from Json_nested_path
objects, or from the rowid value
@param pos NULL means the data should be read from Json_nested_path
objects.
Non-null value is a pointer to previously saved rowid (see
ha_json_table::position() for description)
*/
int ha_json_table::fill_column_values(THD *thd, uchar * buf, uchar *pos)
{
MY_BITMAP *orig_map= dbug_tmp_use_all_columns(table, &table->write_set);
int error= 0;
Counting_error_handler er_handler;
Field **f= table->field;
Json_table_column *jc;
List_iterator_fast<Json_table_column> jc_i(m_jt->m_columns);
my_ptrdiff_t ptrdiff= buf - table->record[0];
Abort_on_warning_instant_set ao_set(table->in_use, FALSE);
enum_check_fields cf_orig= table->in_use->count_cuted_fields;
table->in_use->count_cuted_fields= CHECK_FIELD_ERROR_FOR_NULL;
thd->push_internal_handler(&er_handler);
while (!error && (jc= jc_i++))
{
bool is_null_value;
uint int_pos= 0; /* just to make compilers happy. */
if (!bitmap_is_set(table->read_set, (*f)->field_index))
{
/*
If the RESPONSE_ERROR is set for the column, we have
to unpack it even if it's not in the read_set - to check
for possible errors.
*/
if (jc->m_on_empty.m_response != Json_table_column::RESPONSE_ERROR &&
jc->m_on_error.m_response != Json_table_column::RESPONSE_ERROR)
goto cont_loop;
}
(*f)->move_field_offset(ptrdiff);
/*
Read the NULL flag:
- if we are reading from a rowid value, 0 means SQL NULL.
- if scanning json document, read it from the nested path
*/
if (pos)
is_null_value= !(int_pos= uint4korr(pos));
else
is_null_value= jc->m_nest->m_null;
if (is_null_value)
{
(*f)->set_null();
}
else
{
(*f)->set_notnull();
switch (jc->m_column_type)
{
case Json_table_column::FOR_ORDINALITY:
{
/*
Read the cardinality counter:
- read it from nested path when scanning the json document
- or, read it from rowid when in rnd_pos() call
*/
longlong counter= pos? int_pos: jc->m_nest->m_ordinality_counter;
(*f)->store(counter, TRUE);
break;
}
case Json_table_column::PATH:
case Json_table_column::EXISTS_PATH:
{
json_engine_t je;
json_path_step_t *cur_step;
int array_counters[JSON_DEPTH_LIMIT];
int not_found;
const uchar* node_start;
const uchar* node_end;
/*
Get the JSON context node that we will need to evaluate PATH or
EXISTS against:
- when scanning the json document, read it from nested path
- when in rnd_pos call, the rowid has the start offset.
*/
if (pos)
{
node_start= (const uchar *) (m_js->ptr() + (int_pos-1));
node_end= (const uchar *) m_js->end();
}
else
{
node_start= jc->m_nest->get_value();
node_end= jc->m_nest->get_value_end();
}
json_scan_start(&je, m_js->charset(), node_start, node_end);
cur_step= jc->m_path.steps;
not_found= json_find_path(&je, &jc->m_path, &cur_step, array_counters) ||
json_read_value(&je);
if (jc->m_column_type == Json_table_column::EXISTS_PATH)
{
(*f)->store(!not_found);
}
else /*PATH*/
{
if (not_found)
{
error= jc->m_on_empty.respond(jc, *f, ER_JSON_TABLE_ERROR_ON_FIELD);
}
else
{
if (jc->m_format_json)
{
if (!(error= store_json_in_json(*f, &je)))
error= er_handler.errors;
}
else if (!(error= !json_value_scalar(&je)))
{
store_json_in_field(*f, &je);
error= er_handler.errors;
}
if (error)
{
error= jc->m_on_error.respond(jc, *f,
ER_JSON_TABLE_SCALAR_EXPECTED);
er_handler.errors= 0;
}
else
{
/*
If the path contains wildcards, check if there are
more matches for it in json and report an error if so.
*/
if (jc->m_path.types_used &
(JSON_PATH_WILD | JSON_PATH_DOUBLE_WILD |
JSON_PATH_ARRAY_RANGE) &&
(json_scan_next(&je) ||
!json_find_path(&je, &jc->m_path, &cur_step,
array_counters)))
{
error= jc->m_on_error.respond(jc, *f,
ER_JSON_TABLE_MULTIPLE_MATCHES);
}
}
}
}
break;
}
};
}
(*f)->move_field_offset(-ptrdiff);
cont_loop:
f++;
if (pos)
pos+= 4;
}
dbug_tmp_restore_column_map(&table->write_set, orig_map);
thd->pop_internal_handler();
thd->count_cuted_fields= cf_orig;
return error;
}
int ha_json_table::rnd_pos(uchar * buf, uchar *pos)
{
return fill_column_values(table->in_use, buf, pos) ? HA_ERR_JSON_TABLE : 0;
}
/*
The reference has 4 bytes for every column of the JSON_TABLE.
There it keeps 0 for the NULL values, ordinality index for
the ORDINALITY columns and the offset of the field's data in
the JSON for other column types.
*/
void ha_json_table::position(const uchar *record)
{
uchar *c_ref= ref;
Json_table_column *jc;
List_iterator_fast<Json_table_column> jc_i(m_jt->m_columns);
while ((jc= jc_i++))
{
if (jc->m_nest->m_null)
{
int4store(c_ref, 0);
}
else
{
switch (jc->m_column_type)
{
case Json_table_column::FOR_ORDINALITY:
int4store(c_ref, jc->m_nest->m_ordinality_counter);
break;
case Json_table_column::PATH:
case Json_table_column::EXISTS_PATH:
{
size_t pos= jc->m_nest->get_value() -
(const uchar *) m_js->ptr() + 1;
int4store(c_ref, pos);
break;
}
};
}
c_ref+= 4;
}
}
int ha_json_table::info(uint)
{
/*
We don't want 0 or 1 in stats.records.
Though this value shouldn't matter as the optimizer
supposed to use Table_function_json_table::get_estimates
to obtain this data.
*/
stats.records= 4;
return 0;
}
/**
Create a json table according to a field list.
@param thd thread handle
@param param a description used as input to create the table
@param jt json_table specification
@param table_alias alias
*/
TABLE *Create_json_table::start(THD *thd,
TMP_TABLE_PARAM *param,
Table_function_json_table *jt,
const LEX_CSTRING *table_alias)
{
TABLE *table;
TABLE_SHARE *share;
DBUG_ENTER("Create_json_table::start");
param->tmp_name= "json";
if (!(table= Create_tmp_table::start(thd, param, table_alias)))
DBUG_RETURN(0);
share= table->s;
share->not_usable_by_query_cache= FALSE;
share->db_plugin= NULL;
if (!(table->file= new (&table->mem_root) ha_json_table(share, jt)))
DBUG_RETURN(NULL);
table->file->init();
DBUG_RETURN(table);
}
bool Create_json_table::finalize(THD *thd, TABLE *table,
TMP_TABLE_PARAM *param,
Table_function_json_table *jt)
{
DBUG_ENTER("Create_json_table::finalize");
DBUG_ASSERT(table);
if (Create_tmp_table::finalize(thd, table, param, 1, 0))
DBUG_RETURN(true);
table->db_stat= HA_OPEN_KEYFILE;
if (unlikely(table->file->ha_open(table, table->s->path.str, O_RDWR,
HA_OPEN_TMP_TABLE | HA_OPEN_INTERNAL_TABLE |
HA_OPEN_SIZE_TRACKING)))
DBUG_RETURN(true);
table->set_created();
table->s->max_rows= ~(ha_rows) 0;
param->end_write_records= HA_POS_ERROR;
DBUG_RETURN(0);
}
/*
@brief
Read the JSON_TABLE's field definitions from @jt and add the fields to
table @table.
*/
bool Create_json_table::add_json_table_fields(THD *thd, TABLE *table,
Table_function_json_table *jt)
{
TABLE_SHARE *share= table->s;
Json_table_column *jc;
uint fieldnr= 0;
MEM_ROOT *mem_root_save= thd->mem_root;
List_iterator_fast<Json_table_column> jc_i(jt->m_columns);
Column_derived_attributes da(&my_charset_utf8mb4_general_ci);
DBUG_ENTER("add_json_table_fields");
thd->mem_root= &table->mem_root;
current_counter= other;
while ((jc= jc_i++))
{
Create_field *sql_f= jc->m_field;
List_iterator_fast<Json_table_column> it2(jt->m_columns);
Json_table_column *jc2;
/*
Initialize length from its original value (number of characters),
which was set in the parser. This is necessary if we're
executing a prepared statement for the second time.
*/
sql_f->length= sql_f->char_length;
if (sql_f->prepare_stage1(thd, thd->mem_root,
COLUMN_DEFINITION_TABLE_FIELD,
&da))
goto err_exit;
while ((jc2= it2++) != jc)
{
if (sql_f->field_name.streq(jc2->m_field->field_name))
{
my_error(ER_DUP_FIELDNAME, MYF(0), sql_f->field_name.str);
goto err_exit;
}
}
it2.rewind();
}
jc_i.rewind();
while ((jc= jc_i++))
{
Create_field *sql_f= jc->m_field;
Record_addr addr(!(sql_f->flags & NOT_NULL_FLAG));
Bit_addr bit(addr.null());
uint uneven_delta;
sql_f->prepare_stage2(table->file, table->file->ha_table_flags());
if (!sql_f->charset)
sql_f->charset= &my_charset_utf8mb4_bin;
Field *f= sql_f->type_handler()->make_table_field_from_def(share,
thd->mem_root, &sql_f->field_name, addr, bit, sql_f, sql_f->flags);
if (!f)
goto err_exit;
f->init(table);
uneven_delta= m_uneven_bit_length;
add_field(table, f, fieldnr++, 0);
m_uneven_bit[current_counter]+= (m_uneven_bit_length - uneven_delta);
}
share->fields= fieldnr;
share->blob_fields= m_blob_count;
table->field[fieldnr]= 0; // End marker
share->blob_field[m_blob_count]= 0; // End marker
share->column_bitmap_size= bitmap_buffer_size(share->fields);
thd->mem_root= mem_root_save;
DBUG_RETURN(FALSE);
err_exit:
thd->mem_root= mem_root_save;
DBUG_RETURN(TRUE);
}
/*
@brief
Given a TABLE_LIST representing JSON_TABLE(...) syntax, create a temporary
table for it.
@detail
The temporary table will have:
- fields whose names/datatypes are specified in JSON_TABLE(...) syntax
- a ha_json_table as the storage engine.
The uses of the temporary table are:
- name resolution: the query may have references to the columns of
JSON_TABLE(...). A TABLE object will allow to resolve them.
- query execution: ha_json_table will produce JSON_TABLE's rows.
*/
TABLE *create_table_for_function(THD *thd, TABLE_LIST *sql_table)
{
TMP_TABLE_PARAM tp;
TABLE *table;
uint field_count= sql_table->table_function->m_columns.elements+1;
DBUG_ENTER("create_table_for_function");
tp.init();
tp.table_charset= system_charset_info;
tp.field_count= field_count;
{
Create_json_table maker;
if (!(table= maker.start(thd, &tp,
sql_table->table_function, &sql_table->alias)) ||
maker.add_json_table_fields(thd, table, sql_table->table_function) ||
maker.finalize(thd, table, &tp, sql_table->table_function))
{
if (table)
free_tmp_table(thd, table);
DBUG_RETURN(NULL);
}
}
sql_table->schema_table_name.length= 0;
my_bitmap_map* bitmaps=
(my_bitmap_map*) thd->alloc(bitmap_buffer_size(field_count));
my_bitmap_init(&table->def_read_set, (my_bitmap_map*) bitmaps, field_count);
table->read_set= &table->def_read_set;
bitmap_clear_all(table->read_set);
table->alias_name_used= true;
table->next= thd->derived_tables;
thd->derived_tables= table;
table->s->tmp_table= INTERNAL_TMP_TABLE;
table->grant.privilege= SELECT_ACL;
sql_table->table= table;
DBUG_RETURN(table);
}
int Json_table_column::set(THD *thd, enum_type ctype, const LEX_CSTRING &path,
CHARSET_INFO *cs)
{
set(ctype);
m_explicit_cs= cs;
if (json_path_setup(&m_path, thd->variables.collation_connection,
(const uchar *) path.str, (const uchar *)(path.str + path.length)))
{
report_path_error_ex(path.str, &m_path, "JSON_TABLE", 1,
Sql_condition::WARN_LEVEL_ERROR);
return 1;
}
/*
This is done so the ::print function can just print the path string.
Can be removed if we redo that function to print the path using it's
actual content. Not sure though if we should.
*/
m_path.s.c_str= (const uchar *) path.str;
if (ctype == PATH)
m_format_json= m_field->type_handler() == &type_handler_long_blob_json;
return 0;
}
int Json_table_column::set(THD *thd, enum_type ctype, const LEX_CSTRING &path,
const Lex_column_charset_collation_attrs_st &cl)
{
if (cl.is_empty() || cl.is_contextually_typed_collate_default())
return set(thd, ctype, path, nullptr);
CHARSET_INFO *tmp;
if (!(tmp= cl.resolved_to_character_set(
thd,
thd->variables.character_set_collations,
&my_charset_utf8mb4_general_ci)))
return 1;
return set(thd, ctype, path, tmp);
}
static int print_path(String *str, const json_path_t *p)
{
return str->append('\'') ||
str->append_for_single_quote((const char *) p->s.c_str,
p->s.str_end - p->s.c_str) ||
str->append('\'');
}
/*
Print the string representation of the Json_table_column.
@param thd - the thread
@param f - the remaining array of Field-s from the table
if the Json_table_column
@param str - the string where to print
*/
int Json_table_column::print(THD *thd, Field **f, String *str)
{
StringBuffer<MAX_FIELD_WIDTH> column_type(str->charset());
if (append_identifier(thd, str, &m_field->field_name) ||
str->append(' '))
return 1;
switch (m_column_type)
{
case FOR_ORDINALITY:
if (str->append(STRING_WITH_LEN("FOR ORDINALITY")))
return 1;
break;
case EXISTS_PATH:
case PATH:
{
static const LEX_CSTRING path= { STRING_WITH_LEN(" PATH ") };
static const LEX_CSTRING exists_path= { STRING_WITH_LEN(" EXISTS PATH ") };
(*f)->sql_type(column_type);
if (str->append(column_type) ||
((*f)->has_charset() && m_explicit_cs &&
(str->append(STRING_WITH_LEN(" CHARSET ")) ||
str->append(&m_explicit_cs->cs_name) ||
(Charset(m_explicit_cs).can_have_collate_clause() &&
(str->append(STRING_WITH_LEN(" COLLATE ")) ||
str->append(&m_explicit_cs->coll_name))))) ||
str->append(m_column_type == PATH ? &path : &exists_path) ||
print_path(str, &m_path))
return 1;
break;
}
};
if (m_on_empty.print("EMPTY", str) ||
m_on_error.print("ERROR", str))
return 1;
return 0;
}