diff options
Diffstat (limited to 'sql/item.h')
| -rw-r--r-- | sql/item.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/sql/item.h b/sql/item.h index 29e727b8d5f..00c1468bb48 100644 --- a/sql/item.h +++ b/sql/item.h @@ -1034,9 +1034,47 @@ public: virtual cond_result eq_cmp_result() const { return COND_OK; } inline uint float_length(uint decimals_par) const { return decimals != NOT_FIXED_DEC ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;} + /* Returns total number of decimal digits */ virtual uint decimal_precision() const; + /* Returns the number of integer part digits only */ inline int decimal_int_part() const { return my_decimal_int_part(decimal_precision(), decimals); } + /* + Returns the number of fractional digits only. + NOT_FIXED_DEC is replaced to the maximum possible number + of fractional digits, taking into account the data type. + */ + uint decimal_scale() const + { + return decimals < NOT_FIXED_DEC ? decimals : + is_temporal_type_with_time(field_type()) ? + TIME_SECOND_PART_DIGITS : + MY_MIN(max_length, DECIMAL_MAX_SCALE); + } + /* + Returns how many digits a divisor adds into a division result. + This is important when the integer part of the divisor can be 0. + In this example: + SELECT 1 / 0.000001; -> 1000000.0000 + the divisor adds 5 digits into the result precision. + + Currently this method only replaces NOT_FIXED_DEC to + TIME_SECOND_PART_DIGITS for temporal data types. + This method can be made virtual, to create more efficient (smaller) + data types for division results. + For example, in + SELECT 1/1.000001; + the divisor could provide no additional precision into the result, + so could any other items that are know to return a result + with non-zero integer part. + */ + uint divisor_precision_increment() const + { + return decimals < NOT_FIXED_DEC ? decimals : + is_temporal_type_with_time(field_type()) ? + TIME_SECOND_PART_DIGITS : + decimals; + } /** TIME or DATETIME precision of the item: 0..6 */ |