Package com.mysql.cj.x.protobuf

Class MysqlxResultset.ColumnMetaData

java.lang.Object
com.google.protobuf.AbstractMessageLite
com.google.protobuf.AbstractMessage
com.google.protobuf.GeneratedMessageV3
com.mysql.cj.x.protobuf.MysqlxResultset.ColumnMetaData
All Implemented Interfaces:
com.google.protobuf.Message, com.google.protobuf.MessageLite, com.google.protobuf.MessageLiteOrBuilder, com.google.protobuf.MessageOrBuilder, MysqlxResultset.ColumnMetaDataOrBuilder, java.io.Serializable
Enclosing class:
MysqlxResultset
public static final class MysqlxResultset.ColumnMetaData
extends com.google.protobuf.GeneratedMessageV3
implements MysqlxResultset.ColumnMetaDataOrBuilder
 meta data of a Column
 .. note:: the encoding used for the different ``bytes`` fields in the meta data is externally
   controlled.
   .. seealso:: https://dev.mysql.com/doc/refman/8.0/en/charset-connection.html
 .. note::
   The server may not set the ``original_{table|name}`` fields if they are equal to the plain
   ``{table|name}`` field.
   A client has to reconstruct it like::
     if .original_name is empty and .name is not empty:
       .original_name = .name
     if .original_table is empty and .table is not empty:
       .original_table = .table
 .. note::
   ``compact metadata format`` can be requested by the client. In that case only ``.type`` is set and
   all other fields are empty.
 :param type:
   .. table:: Expected Datatype of Mysqlx.Resultset.Row per SQL Type for non NULL values
     ================= ============ ======= ========== ====== ========
     SQL Type          .type        .length .frac_dig  .flags .charset
     ================= ============ ======= ========== ====== ========
     TINY              SINT         x
     TINY UNSIGNED     UINT         x                  x
     SHORT             SINT         x
     SHORT UNSIGNED    UINT         x                  x
     INT24             SINT         x
     INT24 UNSIGNED    UINT         x                  x
     INT               SINT         x
     INT UNSIGNED      UINT         x                  x
     LONGLONG          SINT         x
     LONGLONG UNSIGNED UINT         x                  x
     DOUBLE            DOUBLE       x       x          x
     FLOAT             FLOAT        x       x          x
     DECIMAL           DECIMAL      x       x          x
     VARCHAR,CHAR,...  BYTES        x                  x      x
     GEOMETRY          BYTES
     TIME              TIME         x
     DATE              DATETIME     x
     DATETIME          DATETIME     x
     YEAR              UINT         x                  x
     TIMESTAMP         DATETIME     x
     SET               SET                                    x
     ENUM              ENUM                                   x
     NULL              BYTES
     BIT               BIT          x
     ================= ============ ======= ========== ====== ========
   .. note:: the SQL "NULL" value is sent as an empty field value in :protobuf:msg:`Mysqlx.Resultset::Row`
   .. seealso:: protobuf encoding of primitive datatypes are decribed in https://developers.google.com/protocol-buffers/docs/encoding
   SINT
     ``.length``
       maximum number of displayable decimal digits (including minus sign) of the type
       .. note::
         valid range is 0-255, but usually you'll see 1-20
       =============== ==
       SQL Type        max digits per type
       =============== ==
       TINY SIGNED      4
       SHORT SIGNED     6
       INT24 SIGNED     8
       INT SIGNED      11
       LONGLONG SIGNED 20
       =============== ==
       .. seealso:: definition of ``M`` in https://dev.mysql.com/doc/refman/8.0/en/numeric-type-overview.html
     ``value``
       variable length encoded signed 64 integer
   UINT
     ``.flags & 1`` (zerofill)
       the client has to left pad with 0's up to .length
     ``.length``
       maximum number of displayable decimal digits of the type
       .. note::
         valid range is 0-255, but usually you'll see 1-20
       ================= ==
       SQL Type          max digits per type
       ================= ==
       TINY UNSIGNED      3
       SHORT UNSIGNED     5
       INT24 UNSIGNED     8
       INT UNSIGNED      10
       LONGLONG UNSIGNED 20
       ================= ==
       .. seealso:: definition of ``M`` in https://dev.mysql.com/doc/refman/8.0/en/numeric-type-overview.html
     ``value``
       variable length encoded unsigned 64 integer
   BIT
     ``.length``
       maximum number of displayable binary digits
       .. note:: valid range for M of the ``BIT`` type is 1 - 64
       .. seealso:: https://dev.mysql.com/doc/refman/8.0/en/numeric-type-overview.html
     ``value``
       variable length encoded unsigned 64 integer
   DOUBLE
     ``.length``
       maximum number of displayable decimal digits (including the decimal point and ``.fractional_digits``)
     ``.fractional_digits``
       maximum number of displayable decimal digits following the decimal point
     ``value``
       encoded as Protobuf's 'double'
   FLOAT
     ``.length``
       maximum number of displayable decimal digits (including the decimal point and ``.fractional_digits``)
     ``.fractional_digits``
       maximum number of displayable decimal digits following the decimal point
     ``value``
       encoded as Protobuf's 'float'
   BYTES, ENUM
     BYTES is used for all opaque byte strings that may have a charset
       * TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB
       * TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT
       * VARCHAR, VARBINARY
       * CHAR, BINARY
       * ENUM
     ``.length``
       the maximum length of characters of the underlying type
     ``.flags & 1`` (rightpad)
       if the length of the field is less than ``.length``, the receiver is
       supposed to add padding characters to the right end of the string.
       If the ``.charset`` is "binary", the padding character is ``0x00``,
       otherwise it is a space character as defined by that character set.
       ============= ======= ======== =======
       SQL Type      .length .charset .flags
       ============= ======= ======== =======
       TINYBLOB      256     binary
       BLOB          65535   binary
       VARCHAR(32)   32      utf8
       VARBINARY(32) 32      utf8_bin
       BINARY(32)    32      binary   rightpad
       CHAR(32)      32      utf8     rightpad
       ============= ======= ======== =======
     ``value``
       sequence of bytes with added one extra '\0' byte at the end. To obtain the
       original string, the extra '\0' should be removed.
       .. note:: the length of the string can be acquired with protobuf's field length() method
         length of sequence-of-bytes = length-of-field - 1
       .. note:: the extra byte allows to distinguish between a NULL and empty byte sequence
   TIME
     A time value.
     ``value``
       the following bytes sequence:
         ``| negate [ | hour | [ | minutes | [ | seconds | [ | useconds | ]]]]``
       * negate - one byte, should be one of: 0x00 for "+", 0x01 for "-"
       * hour - optional variable length encoded unsigned64 value for the hour
       * minutes - optional variable length encoded unsigned64 value for the minutes
       * seconds - optional variable length encoded unsigned64 value for the seconds
       * useconds - optional variable length encoded unsigned64 value for the microseconds
       .. seealso:: protobuf encoding in https://developers.google.com/protocol-buffers/docs/encoding
       .. note:: hour, minutes, seconds, useconds are optional if all the values to the right are 0
       Example: 0x00 -> +00:00:00.000000
   DATETIME
     A date or date and time value.
     ``value``
       a sequence of variants, arranged as follows:
         ``| year | month | day | [ | hour | [ | minutes | [ | seconds | [ | useconds | ]]]]``
       * year - variable length encoded unsigned64 value for the year
       * month - variable length encoded unsigned64 value for the month
       * day - variable length encoded unsigned64 value for the day
       * hour - optional variable length encoded unsigned64 value for the hour
       * minutes - optional variable length encoded unsigned64 value for the minutes
       * seconds - optional variable length encoded unsigned64 value for the seconds
       * useconds - optional variable length encoded unsigned64 value for the microseconds
       .. note:: hour, minutes, seconds, useconds are optional if all the values to the right are 0
     ``.flags & 1`` (timestamp)
       ============= =======
       SQL Type      .flags
       ============= =======
       DATETIME
       TIMESTAMP     1
   DECIMAL
     An arbitrary length number. The number is encoded as a single byte
     indicating the position of the decimal point followed by the Packed BCD
     encoded number. Packed BCD is used to simplify conversion to and
     from strings and other native arbitrary precision math datatypes.
     .. seealso:: packed BCD in https://en.wikipedia.org/wiki/Binary-coded_decimal
     ``.length``
       maximum number of displayable decimal digits (*excluding* the decimal point and sign, but including ``.fractional_digits``)
       .. note:: should be in the range of 1 - 65
     ``.fractional_digits``
       is the decimal digits to display out of length
       .. note:: should be in the range of 0 - 30
     ``value``
       the following bytes sequence:
         ``| scale | BCD | sign | [0x0] |``
       * scale - 8bit scale value (number of decimal digit after the '.')
       * BCD - BCD encoded digits (4 bits for each digit)
       * sign - sign encoded on 4 bits (0xc = "+", 0xd = "-")
       * 0x0 - last 4bits if length(digits) % 2 == 0
       Example: x04 0x12 0x34 0x01 0xd0 -> -12.3401
   SET
     A list of strings representing a SET of values.
     ``value``
       A sequence of 0 or more of protobuf's bytes (length prepended octets) or one of
       the special sequences with a predefined meaning listed below.
       Example (length of the bytes array shown in brackets):
         * ``[0]`` - the NULL value
         * ``[1] 0x00`` - a set containing a blank string ''
         * ``[1] 0x01`` - this would be an invalid value, but is to be treated as the empty set
         * ``[2] 0x01 0x00`` - a set with a single item, which is the '\0' character
         * ``[8] 0x03 F O O 0x03 B A R`` - a set with 2 items: FOO,BAR
 :param name: name of the column
 :param original_name: name of the column before an alias was applied
 :param table: name of the table the column orginates from
 :param original_table: name of the table the column orginates from before an alias was applied
 :param schema: schema the column originates from
 :param catalog:
   catalog the schema originates from
   .. note::
     as there is current no support for catalogs in MySQL, don't expect this field to be set.
     In the MySQL C/S protocol the field had the value ``def`` all the time.
 :param fractional_digits: displayed factional decimal digits for floating point and fixed point numbers
 :param length: maximum count of displayable characters of .type
 :param flags:
   ``.type`` specific flags
   ======= ====== ===========
   type    value  description
   ======= ====== ===========
   UINT    0x0001 zerofill
   DOUBLE  0x0001 unsigned
   FLOAT   0x0001 unsigned
   DECIMAL 0x0001 unsigned
   BYTES   0x0001 rightpad
   ======= ====== ===========
   ====== ================
   value  description
   ====== ================
   0x0010 NOT_NULL
   0x0020 PRIMARY_KEY
   0x0040 UNIQUE_KEY
   0x0080 MULTIPLE_KEY
   0x0100 AUTO_INCREMENT
   ====== ================
   default: 0
 :param content_type:
   a hint about the higher-level encoding of a BYTES field, for more informations
   please refer to Mysqlx.Resultset.ContentType_BYTES enum.
Protobuf type Mysqlx.Resultset.ColumnMetaData
See Also:
Serialized Form