FORMAT() can print more integer digits (than the argument has)
if rounding happens:
FORMAT(9.9,0) -> '10'
The old code did not take this into account.
Fix:
1. One extra digit is needed in case of rounding
- If args[1] is a not-NULL constant, then reserve space for one extra integer
digit if the requested number of decimals is less than args[0]->decimals.
- Otherwise, reserve space for one extra integer digit if
args[0]->decimals is not 0, because rounding can potentially happen
(depending on the exact data in arguments).
2. One extra digit is also needed if the argument has no integer digits,
e.g. in a data type like DECIMAL(38,38).
The conditions 1 and 2 are ORed.
3. Fixing FORMAT_MAX_DECIMALS from 30 to 38. This was forgotten in 10.2.1
(when the limit for the number of fractional digits in DECIMAL was extended).
The code in Item_func_int_val::fix_length_and_dec_int_or_decimal()
calculated badly the result data type for FLOOR()/CEIL(), so for example
the decimal(38,10) input created a decimal(28,0) result.
That was not correct, because one extra integer digit is needed.
floor(-9.9) -> -10
ceil(9.9) -> 10
Rewritting the code in a more straightforward way.
Additional changes:
- FLOOR() now takes into account the presence of the UNSIGNED
flag of the argument: FLOOR(unsigned decimal) does not need an extra digits.
- FLOOR()/CEILING() now preserve the unsigned flag in the result
data type is decimal.
These changes give nicer data types.
Changing that in case of *INT and hex hybrid input:
- ROUND(x,NULL) creates a column with the same type as x.
The old code created a DOUBLE column, which was not relevant at all.
This change simplifies the code a lot.
- ROUND(x,non_constant) creates a column of the INT, BIGINT or DECIMAL
data type (depending on the exact type of x).
The old code created a column of the DOUBLE data type,
which lead to precision loss. Hence MDEV-23366.
- ROUND(bigint_30,negative_constant) creates a column of the DECIMAL(30,0)
data type. The old code created DECIMAL(29,0), which looked strange:
the data type promoted to a higher one, but max length reduced.
Now the length attribute is preserved.
Implementing dedicated fixing methods:
- Type_handler_bit::Item_func_round_fix_length_and_dec()
- Type_handler_bit::Item_func_int_val_fix_length_and_dec()
- Type_handler_typelib::Item_func_round_fix_length_and_dec()
because the inherited methods did not work well.
Fixing:
- Type_handler_typelib::Item_func_int_val_fix_length_and_dec
It did not work well, because it used args[0]->max_length to
calculate the result data type. In case of ENUM and SET it was
not correct, because in FLOOR() and CEILING() context
ENUM and SET return not more than 5 digits (65535 is the biggest
possible value).
Misc:
- Changing the API of
Type_handler_bit::Bit_decimal_notation_int_digits(const Item *item)
to a more generic form:
Type_handler_bit::Bit_decimal_notation_int_digits_by_nbits(uint nbits)
- Fixing Type_handler_bit::Bit_decimal_notation_int_digits_by_nbits() to
return the exact number of decimal digits for all nbits 1..64.
The old implementation was approximate.
This change gives better (more precise) data types.
Item_func_div::fix_length_and_dec_temporal() set the return data type to
integer in case of @div_precision_increment==0 for temporal input with FSP=0.
This caused Item_func_div to call int_op(), which is not implemented,
so a crash on DBUG_ASSERT(0) happened.
Fixing fix_length_and_dec_temporal() to set the result type to DECIMAL.
In main.index_merge_myisam we remove the test that was added in
commit a2d24def8c because
it duplicates the test case that was added in
commit 5af12e4635.
Differences:
MariaDB doesn't support a JSON type therefore the crc32 on those values
are different.
JSON extract syntax is different.
loaddata_utf8 has 3 duplicate lines removed compared to MySQL version.
From mysql-server:
09fdfad50764ff6809e7dd5300e9ce1ab727b62a
e90ae1707e0ca46abc775d1680d1856c4be38b66
described in http://github.com/mysql/mysql-server/pull/157
Apart from external contribution I have added few more additional testcases
for CRC32() function, which are given below.
New Testcases added:
->Verify the crc value of various numeric and string data types(int,
double, blob, text, json, enum, set)
->Verify the crc value when expressions having comparison_operators
and logical_operators
->Verify the crc value for the expression having string_functions,
arithmetic_functions, json_functions
->Verify the crc value for the expression having Geometry functions
like POINT, LINESTRING, MULTILINESTRING, POLYGON, MULTIPOLYGON
->Verify the crc value generated from stored procedures, functions,
triggers, prepare statement, views.
Fix:
Patch based on contribution by Daniel Black (Github user: grooverdan)
Reviewed-by: Anitha Gopi anitha.gopi@oracle.com
Reviewed-by: Srikanth B R srikanth.b.r@oracle.com
RB: 17294
