dbx defined

dbx defined dbtype

Check whether a driver module for the specified database type is either already loaded, or available. If a module can be found, and it not yet loaded, it is automatically loaded.

The return value is a boolean status code. No error is generated when the database type cannot be resolved to a module.

dbx exists

dbx exists dbtype

Check whether a driver module for the specified database type is already loaded. No attempt is made to auto-load a module if it is not already loaded.

The return value is a boolean status code. No error is generated when the database type cannot be resolved to a module.

dbx get

dbx get dbtype attribute

Get an attribute the database driver module. The following attributes can be queried:

• aliases
  A list of recognized alias names of the database type.
• builtin
  A flag indicating whether this driver module is built-in. Built-in module cannot be unloaded.
• affiliation
  The institution the author works for.
• author
  The author of the module, as free-format text.
• authorurl
  A URL with information on the author, or an empty string if unset.
• blobsize
  The default maximum binary blob size.
• category
  A category string to be used if the module is stored in a repository.
• classuuid
  The base class UUID of this database interface module
• comment
  A free-form comment
• date
  The date the module source code was last changed.
• doi
  A digital object identifier for the module, if defined.
• email
  An email contact address of the developer of the module.
• flags
  A collection of flags indicating special capabilities of the module. The only flag currently used is sqlarrays , indicating support for arrays as column data types.
• history
  Module history data
• infourl
  A URL with information on the module, or an empty string if unset.
• keywords
  A list of keywords associated with the module.
• license
  The license class associated with this module. Setting the license to a standard type updates the associated URL with a standard location.
• licenseurl
  A URL with details about the module license.
• literature
  A free-form literature reference.
• name
  The official name of the module. Since the information may be queried via an alias name, this can be different from the command argument.
• orcid
  The ORCID code of the author (see www.orcid.org).
• path
  The repository path for displaying hierarchical repository trees. This attribute is independent of any file system paths.
• port
  The default TCP/IP port used for communication with database servers.
• protocolversion
  The primary protocol version this module supports.
• references
  Cross references of the module. This is a nested list of class UUIDs and reference type tags.
• regid
  For officially registered data driver modules handlers, this is the assigned registration ID. Unregistered modules report zero.
• slot
  The driver table slot this module is loaded into.
• textsize
  The default maximum text blob size.
• version
  Version information for the module.
• versionuuid
  The UUID associated with this module version.

dbx list

dbx list ?pattern?

Return a list of all currently loaded database driver modules. The output may be filtered by a string pattern.

dbx load

dbx load dbtype ?objectfile?

Load or re-load a database interface module. If no object file name is specified, the name of the shared library, DLL or bundle is automatically constructed from the database type name, and the module is located by traversing the database module path, which is accessible via the control array element ::cactvs(databasepath) , but this mechanism can be overridden by specifying an explicit object file with or without a path.

Example:

dbx load mysql

Above statement locates and loads the standard driver for interacting with Mysql and Mariadb databases. Depending on the platform, the object file would be named dbx_mysql.so , dbx_mysql.dll, etc.. It is located in the module directory of a standard Cactvs distribution. The return value of the command is the driver table slot number the module was loaded into.

In case the interface module is already loaded, the current module is unloaded first, so this command can be used to update a driver in a running application. Nevertheless, swapping a driver while database access objects which rely on this driver are in existence in the current process is usually not a good idea, though the details on whether this is possible or not depend on the module implementation.

dbx subcommands

dbx subcommands

This command returns a list of all the defined subcommands of the dbx command.

dbx unload

dbx unload ?dbtype?..

Unload zero or more database connector modules. Built-in modules cannot be unloaded. Unloading connector modules for which there are currently active database management objects is potentially dangerous.