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diff --git a/kexi/doc/dev/kexidb_issues.txt b/kexi/doc/dev/kexidb_issues.txt new file mode 100644 index 00000000..0dd945c6 --- /dev/null +++ b/kexi/doc/dev/kexidb_issues.txt @@ -0,0 +1,211 @@ +--------------------------------------------------------- + KexiDB module IDEAS, ISSUES, PROPOSALS + Copyright (C) 2003 Jaroslaw Staniek js at iidea dot pl + Started: 2003-08-01 + Kexi home page: Users: http://www.koffice.org/kexi/ Developers: http://kexi-project.org + + Changes: + 2005-09-16 Global BLOBs Storage +--------------------------------------------------------- + +| +| This document is expected to be independent of given KexiDB dirver implementation, +| but proposals are described here are after certain decisions has been made: +| -drivers are (by current importance): SQLite (embedded), +| ODBC (universality reasons ), Mysql (historical reasons), PostgreSQL +| + +----------------------------------------------------------------- + +1. EXTENSION: Option for setting user-defined error messages on selected error types. + +Since new KexiDB has fully i18n'd user-visible messages, it outperforms other products as MSA +(that often shows confusing message coming directly from the engine). There is possibility +to provide users with table of error messages that they can personalize. These settings can +be properties of table (query, form, etc.) and thus can be inherited (eg. by form from a table). +By default, i18n'd messages from KexiDB can be presented. + +<EXAMPLE> +Before we set our message for UNIQUE KEY conflict for table Cars (name varchar UNIQUE, price integer), +we have got this message when try to violate 'unique' restionction: +"There is already added one record with field 'name' set to 'Dodge' in table 'Cars'. +This field must be unique." +Now, we want more descriptive message: "There should be only one car named 'Dodge'!". +We write this not as above, but rather: "There should be only one car named %field%!", +since %field% is automatically substituted by given field value. After this we get message +that is easier to understand for everyday user. Of course Kexi (and competitors too) never will +be so clever as a human in building such messages automatically. +</EXAMPLE> + +<NOTE>Inheriting messages: it will be more conventient to set up custom messages (if required) +for table definition rather than just in form. If we set up given message in for a table, every +form that uses this table as data source (end every query that do so) can use this message when needed. +This note is also useful for other types of properties that can be inherited by extended objects from. +</NOTE> + +----------------------------------------------------------------- + +2. KexiDB classes inheritance diagram + +TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO + +Object + DriverManager + Driver + [DRIVER]Driver + Connection + [DRIVER]Connection + +[DRIVER] should be substituted by SQLite, MySQL, etc. +These are classess to reimplement in the drivers. + +ConnectionData +Field +Cursor + [DRIVER]Cursor +FieldList + TableSchema + QuerySchema + IndexSchema +Transaction +TransactionGuard +BaseExpr + NArgExpr + UnaryExpr + BinaryExpr + ConstExpr + VariableExpr + +----------------------------------------------------------------- + +3. Table schema, query schema, etc. storage + +Table or query schemas are extended with additional properties, +usually not available from most db engines or even related to gui. + +//This table contains list of kexi object stored within project (tables, queries, etc.) +kexi__objects + o_id integer unsigned primary key auto_increment, + o_type byte, //type id taken from KexiDB::ObjectTypes + o_name varchar(200), + o_caption varchar(200), //optional, enriched name, can contain non-latin1 characters + o_help varchar + +//This table contains object's data, such as form's xml def. +kexi__objectdata + o_id integer REFERENCES kexi__objects(o_id), + o_data varchar, + o_sub_id varchar(200) //sometimes single object can have more than one data + //-these can be identified by o_sub_id + //if not needed, leave it as NULL + + +//This table contains fields that are members of given kexi object. +//Not all object types should be allowed, now allowed are tables and queries +kexi__fields + t_id integer REFERENCES kexi__objects(o_id), + f_type byte, + f_name varchar(200), + f_length integer, + f_precision integer, + f_constraints integer, + f_options integer, + f_default varchar, +//these are additional properties: + f_order integer, + f_caption varchar(200), + f_help varchar + +//This table contains a list of parts defined for this database +kexi__parts + p_id integer unsigned primary key auto_increment, + p_name varchar(200), + p_mime varchar(200), + p_url varchar +TODO: add version? + +//This table contains global (predefined or not) properties for this database +kexi__db + db_property varchar(32), + db_value varchar + +//Predefined properties stored in kexi__db: +property="kexidb_major_ver", value=<major_version> + Where: <version> is a string containing integer in textual form that denotes + KexiDB implementation major version used to create or update this database. + This property is useful for KexiDB library and applications to denote + what KexiDB features could be available. This ensures backward compatibility + and (at least in some cases) -- forward compatibility. +property="kexidb_minor_ver", value=<minor_version> + like above -- minor KexiDB version +property="project_caption", value=<string> +property="project_desc", value=<string> + +TODO: put more props. todo - creator, created date, etc. (also to KexiProjectData) + +// Global BLOBs Storage (BLOB == BINARY LARGE OBJECT) +// Designed to store any kind of static images, sound and other binary data +//Table: +kexi__blobs + o_id integer unsigned primary key auto_increment, //unique project-wide identifier of a BLOB + o_data BLOB, + o_name varchar(200), //optional, name of the blob, + //can be e.g. a name of original file the data comes from, + //can contain non-latin1 characters + o_caption varchar(200), //optional, enriched name, can contain non-latin1 characters + o_mime varchar(200) NOT NULL, //MIME type of a BLOB, e.g. image/jpg + o_folder_id integer unsigned //references kexi__gallery_folders.f_id + //If null, the BLOB only points to virtual "All" folder + //WILL BE USED in Kexi >=1.1 + +//(not yet implemented, planned for 1.1) +//User-defined folders for better BLOBs categorizing. +//For simplification, folders have no lowlevel name but only caption. +//By default there are no physical folders, but only following virtual: +//-"All" folder +//-"Used" folder (computation of this takes some time because design of forms +// and reports needs to be parsed) +//-"Unused" folder (the same note as for "Used) +//-"By type" folder with "jpeg", "png" subfolders, etc. - available by grepping using BLOB's o_mime +kexi__gallery_folders + f_id integer unsigned primary key auto_increment, //unique id of a folder + f_parent_id integer unsigned //references f_id, can be null for top level folders + f_caption varchar(200), //optional, enriched name, can contain non-latin1 characters + f_notes varchar, //optional notes + +----------------------------------------------------------------- + +4. Extended table schema information: + +Docs available online: +- http://kexi-project.org/wiki/wikiview/index.php?ExtendedTableSchemaInformation +- Table Column Lookup: http://kexi-project.org/wiki/wikiview/index.php?KexiDBLookupColumns + +----------------------------------------------------------------- + +5. DEPRECATED TABLES + +//This table contains additional information for query schemas +kexi__querydata + q_id integer REFERENCES kexi__objects(o_id), + q_sql varchar, //raw sql text - stored in the unchanged form entered by a user (or generated) + q_valid boolean, //query schema may be invalid (syntactically or logically, + //but still can be stored) + q_parent_tab integer REFERENCES kexi__objects(o_id) //parent table of this query + +//This table contains information about fields defined in select queries +kexi__queryfields + q_id integer REFERENCES kexi__objects(o_id), + f_order integer, //order of this field in query schema + f_id integer REFERENCES kexi__objects(f_order), //may be NULL if a field is asterisk + f_tab_asterisk integer REFERENCES kexi__objects(o_id), //if this is "single-table" asterisk + //this member references to valid tables id, otherwise is NULL + f_alltab_asterisk boolean //true if this is "all-tables" asterisk, otherwise false + +//This table contains information about tables used by select queries +kexi__querytables + q_id integer REFERENCES kexi__objects(o_id), + t_id integer REFERENCES kexi__objects(o_id), //references to table used by given q_id + t_order integer //order of t_id table in query schema's tables list + + |