/MariaDB.jl

Julia wrapper for MariaDB Connector/C

Primary LanguageJuliaMIT LicenseMIT

MariaDB.jl

Build Status

A wrapper around the MariaDB C connector.

Install

Before using MariaDB, make sure you have the MariaDB c connector installed: MariaDB C Connector

You can install MariaDB.jl via the Julia package manager:

julia> Pkg.clone("https://github.com/Dynactionize/MariaDB.jl.git")
julia> using MariaDB

Documentation

The wrapper is an almost one-on-one mapping of the interface of the C connector. You can retrieve the documentation via the inline Julia help system.

More documentation can also be found on the MariaDB C Connector - API Ref.

Some MariaDB.jl specific documentation can be found in the following sections.

Types

The following types are availabe:

  • MYSQL

    Represents a handle to one database connection. It is used for almost all functions.

  • MYSQL_RES

    Represents the result of a query that returns rows (SELECT, SHOW, DESCRIBE, EXPLAIN). The information returned from a query is calle the result set.

  • MYSQL_ROW

    This is a type-safe representation of one row of data. It is currently implemented as an array of bytestrings (Vector{ByteString}).

  • MYSQL_FIELD

    Contains metadata: information about a field, such as the field's name, type and size. It has the following members:

    • name

      The name of the field. If the fies was given an alias with an AS clause, the value of the name is the alias

    • org_name

      The name of the fiels. Aliases are ignored. For expressions, the value is an empty string

    • table

      The name of the table containting this field, if it is not a calculated field. For calculated fields, the table value is an empty string. If the column is selected from a view, table names the view. IF teh table or view was given an alias, with an AS clause, the value of table is the alias. for a UNION the value is the empty string.

    • org_table

      The name of teh table. Aliases are ignored. If the column is selected from a view, org_table names the view. For a UNION the value is the empty string.

    • db

      The The name of the database that the field comes from. If the field is a calculated field, db is an empty string. For a UNION, the value is the empty string.

    • catalog

      The catalog name. This value is always "def".

    • def

      The default value of this field.

    • length

      The width of the field, This corresponds to the display length, in bytes.

      The server determines the length value before it generates the result set, so this is the minimum length required for a data type capable of holding the largest possible value from the result column, without knowing in advance the actual values that will be produced by the query for the result set.

    • max_length

      The maximum width of the field for the result set (the length in bytes of the longest field value for the rows actually in the result set). If you use mysql_store_result(), this contains the maximum length for the field. If you use mysql_use_result(), the value of this variable is zero.

      The value of max_length is the length of the string representation of teh values in the result set. For example, if you retrieve a FLOAT column and the widest value is -12.345, max_length is 7 (the length of "-12.345").

    • flags

      Bit-flag that describes the field. The flags value may have zero or more of the bits set that are shown in the following table:

      Flag Value Flag Description
      NOT_NULL_FLAG Field can not be NULL
      PRI_KEY_FLAG Field is part of a primary key
      UNIQUE_KEY_FLAG Field is part of a unique key
      MULTIPLE_KEY_FLAG Field is part of a nonunique key
      UNSIGNED_FLAG Field has the UNSIGNED attribute
      ZEROFILL_FLAG Field has the ZEROFILL attribute
      BINARY_FLAG Field has the BINARY attribute
      AUTO_INCREMENT_FLAG Field has the AUTO_INCREMENT attributes
      ENUM_FLAG Field is an ENUM
      SET_FLAG Field is a SET
      BLOB_FLAG Field is a BLOB or TEXT (deprecated)
      TIMESTAMP_FLAG Field is a TIMESTAMP (deprecated)
      NUM_FLAG Field is numeric; see additional notes following table
      NO_DEFAULT_VALUE_FLAG Field has no default value; see additional notes following table

      Some of these falgs indicate data type information and are superseded by or used in conjunction with the MYSQL_TYPE_xxx value in the field.type member described later:

      • To check for BLOB or TIMESTAMP values, check wether type is MYSQL_TYPE_BLOB or MYSQL_TYPE_TIMESTAMP. (The BLOB_FLAG and TIMESTAMP_FLAG flags are unneeded.)

      • ENUM and SET values are returned as strings. For these, check that the type value is MYSQL_TYPE_STRING and that the ENUM_FLAG or SET_FLAG is set in teh flags value.

      NUM_FLAG indicates that a column is numeric. This includes columns with a decimal, integer, floating point, NULL and year value.

      NO_DEFAULT_VALUE_FLAG indicates that a column has no DEFAULT clause in it's definition. This does not apply to NULL columns (because such columns have a default NULL), or to AUTO_INCREMENT columns (which have an implied default value).

    • decimals

      The number of decimals for numeric fields.

    • charsetnr

      An ID number that indicates the characterset/collactino pair for the field.

      To distinguish between binary and nonbinary data for string data types, check wether the charsetnr value is 63. If so, the character set is binary, which indicates binary rather than nonbinary data. This enables you to distinguis BINARY from CHAR, VARBINARY from VARCHAR, and the BLOB types from the TEXT types.

      charsetnr values are the same as those displayed in the Id column of teh SHOW COLLATION statement or the ID column of the INFORMATION_SCHEMA.COLLATIONS table. You can use those information sources to see which character set and collation specific charsetnr values indicate.

    • field_types

      The type of teh field. The type value may be one of the MYSQL_TYPE_ symbols shown in the following table:

      Type Value Type Description
      MYSQL_TYPE_TINY 1-byte integer field
      MYSQL_TYPE_SHORT 2-byte integer field
      MYSQL_TYPE_LONG 4-byte integer field
      MYSQL_TYPE_INT24 3-byte integer field
      MYSQL_TYPE_LONGLONG 8-byte integer field
      MYSQL_TYPE_DECIMAL decimal field
      MYSQL_TYPE_NEWDECIMAL precision math decimal field
      MYSQL_TYPE_FLOAT 4-byte single precision floating point field
      MYSQL_TYPE_DOUBLE 8-byte double precision floating point field
      MYSQL_TYPE_BIT 1-64 bits field
      MYSQL_TYPE_TIMESTAMP timestamp field
      MYSQL_TYPE_DATE date field
      MYSQL_TYPE_TIME time field
      MYSQL_TYPE_DATETIME datetime field
      MYSQL_TYPE_YEAR 1-byte year field (range = 1901 - 2155)
      MYSQL_TYPE_STRING char or binary field
      MYSQL_TYPE_VAR_STRING varchar or varbinary field
      MYSQL_TYPE_BLOB blob or text field
      MYSQL_TYPE_SET set field
      MYSQL_TYPE_ENUM enum field
      MYSQL_TYPE_GEOMETRY spatial field
      MYSQL_TYPE_NULL NULL-type field

  • MYSQL_FIELD_OFFSET

    This is a type-safe representation of an offset into a MySQL field list. Offsets are field numbers within a row, beginning at zero.

  • MYSQL_ROW_OFFSET

    Represents an offset in a MYSQL_RES, pointing to an actual MYSQL_ROW.