# Result Set Packets MariaDB Server sends the following packets as part of a result set. A result set consists of different packets: * [Result set metadata](#ResultSet-metadata). * 1 [column count packet](#column-count-packet). * If not (`MARIADB_CLIENT_CACHE_METADATA` capability set) `OR` (send metadata == 1): * For each column (for instance, `column_count` times): * [Column Definition packet](#column-definition-packet). * If not (`CLIENT_DEPRECATE_EOF` capability set) [EOF\_Packet](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/eof_packet). * n [result set row](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/resultset-row). * If error: * [ERR\_Packet](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/err_packet). * Else: * If `CLIENT_DEPRECATE_EOF` capability: * [OK\_Packet](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/ok_packet) with a `0xFE` header. * Else [EOF\_Packet](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/eof_packet). {% hint style="warning" %} It is unsafe to assume that any packet with a `0xFE` header is an [OK packet (OK\_Packet)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/ok_packet) or an [EOF packet (EOF\_Packet)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/eof_packet), because [result set row packets (ResultsetRow)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/resultset-row) can also begin with `0xFE` when using the text protocol with a field length greater than `0xFFFFFF`.\ To safely confirm that a packet with a `0xFE` header is an [OK packet (OK\_Packet)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/ok_packet) or an [EOF packet (EOF\_Packet)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/eof_packet), you must also check that the packet length is less than `0xFFFFFF`. {% endhint %} ## Column Count Packet The column count packet describes the number of columns in the result set. It uses the following format: * [int\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-integers) column count. * If (`MARIADB_CLIENT_CACHE_METADATA` capability set): * int<1> metadata follows (0 / 1). The metadata indicator byte is only present if both the client and the server declare the `MARIADB_CLIENT_CACHE_METADATA` capability. If the metadata byte is set to `1`, the normal metadata follows the column definitions. If the metadata byte is set to `0`, the Column Count Packet is immediately followed by the second [EOF packet (EOF\_Packet)](https://mariadb.com/docs/server/reference/clientserver-protocol/4-server-response-packets/eof_packet) or the result set rows if the `CLIENT_DEPRECATE_EOF` capability is set. ## Column Definition Packet A column definition packet describes a column in the result set. It uses the following format: * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) catalog (always 'def'). * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) schema. * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) table alias. * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) table. * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) column alias. * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) column. * If extended type supported (see `MARIADB_CLIENT_EXTENDED_METADATA` ): * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) [extended metadata](#extended-metadata). * [int\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-integers) length of fixed fields (=0xC). * [int<2>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) character set number. * [int<4>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) max. column size. * [int<1>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) [Field types](#field-types). * [int<2>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) [Field detail flag](#field-details-flag). * [int<1>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) decimals. * [int<2>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) - unused - ## Field Types The column type field in the column definition packet describes the base type of the column. It also indicates how the values are encoded for `COM_STMT_EXECUTE` parameters and binary result set rows. | Value | Protocol Column Type | Encoding | | ----- | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 0 | MYSQL\_TYPE\_DECIMAL | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 1 | MYSQL\_TYPE\_TINY | [TINYINT Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#tinyint-binary-encoding) | | 2 | MYSQL\_TYPE\_SHORT | [SMALLINT Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#smallint-binary-encoding) | | 3 | MYSQL\_TYPE\_LONG | [INTEGER Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#integer-binary-encoding) | | 4 | MYSQL\_TYPE\_FLOAT | [FLOAT Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#float-binary-encoding) | | 5 | MYSQL\_TYPE\_DOUBLE | [DOUBLE Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#double-binary-encoding) | | 6 | MYSQL\_TYPE\_NULL | Not used, being NULL is indicated by the NULL-bitmap in the result | | 7 | MYSQL\_TYPE\_TIMESTAMP | [TIMESTAMP Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#timestamp-binary-encoding) | | 8 | MYSQL\_TYPE\_LONGLONG | [BIGINT Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#bigint-binary-encoding) | | 9 | MYSQL\_TYPE\_INT24 | [INTEGER Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#integer-binary-encoding) | | 10 | MYSQL\_TYPE\_DATE | [TIMESTAMP Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#timestamp-binary-encoding) | | 11 | MYSQL\_TYPE\_TIME | [TIME Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#time-binary-encoding) | | 12 | MYSQL\_TYPE\_DATETIME | [TIMESTAMP Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#timestamp-binary-encoding) | | 13 | MYSQL\_TYPE\_YEAR | [SMALLINT Binary encoding](https://mariadb.com/docs/server/reference/clientserver-protocol/resultset-row#smallint-binary-encoding) | | 14 | MYSQL\_TYPE\_NEWDATE | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 15 | MYSQL\_TYPE\_VARCHAR | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 16 | MYSQL\_TYPE\_BIT | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 17 | MYSQL\_TYPE\_TIMESTAMP2 | Used only in the replication protocol | | 18 | MYSQL\_TYPE\_DATETIME2 | Used only in the replication protocol | | 19 | MYSQL\_TYPE\_TIME2 | Used only in the replication protocol | | 245 | MYSQL\_TYPE\_JSON | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) (only used with MySQL, MariaDB uses MYSQL\_TYPE\_STRING for JSON) | | 246 | MYSQL\_TYPE\_NEWDECIMAL | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 247 | MYSQL\_TYPE\_ENUM | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 248 | MYSQL\_TYPE\_SET | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 249 | MYSQL\_TYPE\_TINY\_BLOB | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 250 | MYSQL\_TYPE\_MEDIUM\_BLOB | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 251 | MYSQL\_TYPE\_LONG\_BLOB | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 252 | MYSQL\_TYPE\_BLOB | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 253 | MYSQL\_TYPE\_VAR\_STRING | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 254 | MYSQL\_TYPE\_STRING | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | | 255 | MYSQL\_TYPE\_GEOMETRY | [byte encoding](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-bytes) | ## Field Details Flag The column details flag describes certain column attributes and whether certain column options are set. It is a bitmask with the following flags: | Flag Value | Flag Name | Flag Description | | ---------- | ------------------------ | ----------------------------------------- | | 1 | NOT\_NULL | field cannot be null | | 2 | PRIMARY\_KEY | field is a primary key | | 4 | UNIQUE\_KEY | field is unique | | 8 | MULTIPLE\_KEY | field is in a multiple key | | 16 | BLOB | is this field a Blob | | 32 | UNSIGNED | is this field unsigned | | 64 | ZEROFILL\_FLAG | is this field a zerofill | | 128 | BINARY\_COLLATION | whether this field has a binary collation | | 256 | ENUM | Field is an enumeration | | 512 | AUTO\_INCREMENT | field auto-increment | | 1024 | TIMESTAMP | field is a timestamp value | | 2048 | SET | field is a SET | | 4096 | NO\_DEFAULT\_VALUE\_FLAG | field doesn't have default value | | 8192 | ON\_UPDATE\_NOW\_FLAG | field is set to NOW on UPDATE | | 32768 | NUM\_FLAG | field is num | {% hint style="info" %} The `BLOB` flag cannot be used to determine if a column has binary data, because [BINARY](https://mariadb.com/docs/server/reference/data-types/string-data-types/binary) and [VARBINARY](https://mariadb.com/docs/server/reference/data-types/string-data-types/varbinary) columns are treated as strings, instead of blobs. The `BINARY_COLLATION` flag can be used to determine if a string column has binary data. {% endhint %} ## Extended Metadata This extended column type information can be used to find out more specific details about the column type: * For a [POINT](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-constructors/point) column, the column type field is `MYSQL_TYPE_GEOMETRY`, but the extended type indicates 'point'. * For a [JSON](https://mariadb.com/docs/server/reference/data-types/string-data-types/json) column, the column type field is `MYSQL_TYPE_STRING`, but the extended type indicates 'json'. * While string has data: * [int<1>](https://mariadb.com/docs/server/reference/protocol-data-types#fixed-length-integers) data type: 0x00:type, 0x01: format. * [string\](https://mariadb.com/docs/server/reference/protocol-data-types#length-encoded-strings) value. *This page is licensed: CC BY-SA / Gnu FDL* {% @marketo/form formId="4316" %}