diff options
Diffstat (limited to 'sql/field.h')
| -rw-r--r-- | sql/field.h | 51 |
1 files changed, 36 insertions, 15 deletions
diff --git a/sql/field.h b/sql/field.h index e832928b114..162812adfba 100644 --- a/sql/field.h +++ b/sql/field.h @@ -464,32 +464,53 @@ public: */ virtual void sql_type(String &str) const =0; virtual uint size_of() const =0; // For new field - inline bool is_null(my_ptrdiff_t row_offset= 0) - { return null_ptr ? (null_ptr[row_offset] & null_bit ? 1 : 0) : table->null_row; } - inline bool is_real_null(my_ptrdiff_t row_offset= 0) + inline bool is_null(my_ptrdiff_t row_offset= 0) const + { + /* + The table may have been marked as containing only NULL values + for all fields if it is a NULL-complemented row of an OUTER JOIN + or if the query is an implicitly grouped query (has aggregate + functions but no GROUP BY clause) with no qualifying rows. If + this is the case (in which TABLE::null_row is true), the field + is considered to be NULL. + Note that if a table->null_row is set then also all null_bits are + set for the row. + + Otherwise, if the field is NULLable, it has a valid null_ptr + pointer, and its NULLity is recorded in the "null_bit" bit of + null_ptr[row_offset]. + */ + return (table->null_row ? TRUE : + null_ptr ? test(null_ptr[row_offset] & null_bit) : 0); + } + inline bool is_real_null(my_ptrdiff_t row_offset= 0) const { return null_ptr ? (null_ptr[row_offset] & null_bit ? 1 : 0) : 0; } - inline bool is_null_in_record(const uchar *record) + inline bool is_null_in_record(const uchar *record) const { if (!null_ptr) return 0; return test(record[(uint) (null_ptr -table->record[0])] & null_bit); } - inline bool is_null_in_record_with_offset(my_ptrdiff_t col_offset) - { - if (!null_ptr) - return 0; - return test(null_ptr[col_offset] & null_bit); - } inline void set_null(my_ptrdiff_t row_offset= 0) { if (null_ptr) null_ptr[row_offset]|= null_bit; } inline void set_notnull(my_ptrdiff_t row_offset= 0) { if (null_ptr) null_ptr[row_offset]&= (uchar) ~null_bit; } - inline bool maybe_null(void) { return null_ptr != 0 || table->maybe_null; } - /** - Signals that this field is NULL-able. - */ - inline bool real_maybe_null(void) { return null_ptr != 0; } + inline bool maybe_null(void) const + { return null_ptr != 0 || table->maybe_null; } + + /* @return true if this field is NULL-able, false otherwise. */ + inline bool real_maybe_null(void) const { return null_ptr != 0; } + uint null_offset(const uchar *record) const + { return (uint) (null_ptr - record); } + + uint null_offset() const + { return null_offset(table->record[0]); } + void set_null_ptr(uchar *p_null_ptr, uint p_null_bit) + { + null_ptr= p_null_ptr; + null_bit= p_null_bit; + } inline THD *get_thd() { return table ? table->in_use : current_thd; } |