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author | Monty <monty@mariadb.org> | 2016-06-18 14:28:34 +0300 |
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committer | Monty <monty@mariadb.org> | 2016-06-22 22:04:55 +0300 |
commit | 34eb10e4064a7f38fc7d41016a6bcc5443ebe0c3 (patch) | |
tree | 45f76f02034419697e5bff5f539b20eaac8f8c8d /libmysql/libmysql.c | |
parent | e4062d4d203a6be596d3f61dfe4db1b4f91e24aa (diff) | |
download | mariadb-git-34eb10e4064a7f38fc7d41016a6bcc5443ebe0c3.tar.gz |
MDEV-10138 Support for decimals up to 38 digits
Decimals with float, double and decimal now works the following way:
- DECIMAL_NOT_SPECIFIED is used when declaring DECIMALS without a firm number
of decimals. It's only used in asserts and my_decimal_int_part.
- FLOATING_POINT_DECIMALS (31) is used to mark that a FLOAT or DOUBLE
was defined without decimals. This is regarded as a floating point value.
- Max decimals allowed for FLOAT and DOUBLE is FLOATING_POINT_DECIMALS-1
- Clients assumes that float and double with decimals >= NOT_FIXED_DEC are
floating point values (no decimals)
- In the .frm decimals=FLOATING_POINT_DECIMALS are used to define
floating point for float and double (31, like before)
To ensure compatibility with old clients we do:
- When storing float and double, we change NOT_FIXED_DEC to
FLOATING_POINT_DECIMALS.
- When creating fields from .frm we change for float and double
FLOATING_POINT_DEC to NOT_FIXED_DEC
- When sending definition for a float/decimal field without decimals
to the client as part of a result set we convert NOT_FIXED_DEC to
FLOATING_POINT_DECIMALS.
- variance() and std() has changed to limit the decimals to
FLOATING_POINT_DECIMALS -1 to not get the double converted floating point.
(This was to preserve compatiblity)
- FLOAT and DOUBLE still have 30 as max number of decimals.
Bugs fixed:
variance() printed more decimals than we support for double values.
New behaviour:
- Strings now have 38 decimals instead of 30 when converted to decimal
- CREATE ... SELECT with a decimal with > 30 decimals will create a column
with a smaller range than before as we are trying to preserve the number of
decimals.
Other changes
- We are now using the obsolete bit FIELDFLAG_LEFT_FULLSCREEN to specify
decimals > 31
- NOT_FIXED_DEC is now declared in one place
- For clients, NOT_FIXED_DEC is always 31 (to ensure compatibility).
On the server NOT_FIXED_DEC is DECIMAL_NOT_SPECIFIED (39)
- AUTO_SEC_PART_DIGITS is taken from DECIMAL_NOT_SPECIFIED
- DOUBLE conversion functions are now using DECIMAL_NOT_SPECIFIED instead of
NOT_FIXED_DEC
Diffstat (limited to 'libmysql/libmysql.c')
-rw-r--r-- | libmysql/libmysql.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c index e91b3f75614..0622b7a1a78 100644 --- a/libmysql/libmysql.c +++ b/libmysql/libmysql.c @@ -3479,7 +3479,7 @@ static void fetch_float_with_conversion(MYSQL_BIND *param, MYSQL_FIELD *field, */ char buff[FLOATING_POINT_BUFFER]; size_t len; - if (field->decimals >= NOT_FIXED_DEC) + if (field->decimals >= FLOATING_POINT_DECIMALS) len= my_gcvt(value, type, (int) MY_MIN(sizeof(buff)-1, param->buffer_length), buff, NULL); |