diff options
Diffstat (limited to 'sql/field.h')
| -rw-r--r-- | sql/field.h | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/sql/field.h b/sql/field.h index cb7f94b6437..7199e40c173 100644 --- a/sql/field.h +++ b/sql/field.h @@ -844,7 +844,7 @@ public: my_ptrdiff_t l_offset= (my_ptrdiff_t) (table->s->default_values - table->record[0]); memcpy(ptr, ptr + l_offset, pack_length()); - if (null_ptr) + if (maybe_null_in_table()) *null_ptr= ((*null_ptr & (uchar) ~null_bit) | (null_ptr[l_offset] & null_bit)); } @@ -1024,9 +1024,9 @@ public: { return null_ptr && (null_ptr[row_offset] & null_bit); } inline bool is_null_in_record(const uchar *record) const { - if (!null_ptr) - return 0; - return record[(uint) (null_ptr - table->record[0])] & null_bit; + if (maybe_null_in_table()) + return record[(uint) (null_ptr - table->record[0])] & null_bit; + return 0; } inline void set_null(my_ptrdiff_t row_offset= 0) { if (null_ptr) null_ptr[row_offset]|= null_bit; } @@ -1035,10 +1035,19 @@ public: inline bool maybe_null(void) const { return null_ptr != 0 || table->maybe_null; } - /* @return true if this field is NULL-able, false otherwise. */ + /* @return true if this field is NULL-able (even if temporarily) */ inline bool real_maybe_null(void) const { return null_ptr != 0; } uint null_offset(const uchar *record) const { return (uint) (null_ptr - record); } + /* + For a NULL-able field (that can actually store a NULL value in a table) + null_ptr points to the "null bitmap" in the table->record[0] header. For + NOT NULL fields it is either 0 or points outside table->record[0] into the + table->triggers->extra_null_bitmap (so that the field can store a NULL + value temporarily, only in memory) + */ + bool maybe_null_in_table() const + { return null_ptr >= table->record[0] && null_ptr <= ptr; } uint null_offset() const { return null_offset(table->record[0]); } @@ -3600,6 +3609,7 @@ enum_field_types get_blob_type_from_length(ulong length); uint32 calc_pack_length(enum_field_types type,uint32 length); int set_field_to_null(Field *field); int set_field_to_null_with_conversions(Field *field, bool no_conversions); +int convert_null_to_field_value_or_error(Field *field); /* The following are for the interface with the .frm file |