Database extractor - Revision history

Akivela: Generic SQL database import moved to Database extractor

2011-08-12T14:36:49Z

Generic SQL database import moved to Database extractor

Akivela at 13:34, 15 March 2009

2009-03-15T13:34:03Z

Akivela at 13:33, 15 March 2009

2009-03-15T13:33:45Z

Olli at 08:53, 11 September 2008

2008-09-11T08:53:25Z

Akivela at 18:25, 8 May 2008

2008-05-08T18:25:13Z

Akivela at 16:43, 14 May 2007

2007-05-14T16:43:20Z

Olli at 13:02, 16 February 2007

2007-02-16T13:02:26Z

Akivela at 16:06, 12 February 2007

2007-02-12T16:06:29Z

Akivela: /* Using the database import tool */

2007-02-08T09:52:45Z

‎Using the database import tool

Olli: /* Using the database import tool */

2007-01-24T12:40:16Z

‎Using the database import tool

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 == Using the database import tool ==
-Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Other > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is already configured or create a new database entry and fill in appropriate connection details.
+Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract > Other''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is already configured or create a new database entry and fill in appropriate connection details.
 After selecting the database the tool will show the database schema with options on how to process each column. You can ignore some columns by unchecking the include check box. To ignore a complete table, uncheck all its columns. You can also choose to make topics from column values instead of making occurrences (see conversion details below). You can also choose which column will be used as topic base name.

@@ Line 3: / Line 3: @@
 == Using the database import tool ==
-Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is already configured or create a new database entry and fill in appropriate connection details.
+Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Other > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is already configured or create a new database entry and fill in appropriate connection details.
 After selecting the database the tool will show the database schema with options on how to process each column. You can ignore some columns by unchecking the include check box. To ignore a complete table, uncheck all its columns. You can also choose to make topics from column values instead of making occurrences (see conversion details below). You can also choose which column will be used as topic base name.

← Older revision		Revision as of 08:53, 11 September 2008
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	Tables with only one primary key that is also a foreign key are also treated slightly differently. This kind of table can usually be thought to be extending another row in the table that is referenced. For this reason subject identifier is created with the table name of the referenced table. This will cause topics of both this and the referenced tables to merge. This means that information from both tables will be in the same topic.		Tables with only one primary key that is also a foreign key are also treated slightly differently. This kind of table can usually be thought to be extending another row in the table that is referenced. For this reason subject identifier is created with the table name of the referenced table. This will cause topics of both this and the referenced tables to merge. This means that information from both tables will be in the same topic.
		+
		+	== Troubleshooting ==
		+
		+	Zero dates in MySQL database may cause some trouble in SQL database import. Default behavior for MySQL JDBC driver is to throw an exception whenever such a value is encountered. This results in an error message in Wandora:
		+
		+	''org.wandora.topicmap.TopicMapException: java.sql.SQLException: Cannot convert value '0000-00-00 00:00:00' from column 3 to TIMESTAMP.''
		+
		+	This behavior can be changed with connection parameter as documented [http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html here]. However, using the MySQL template in database configuration hides the actual connection string so you can't add any connection parameters. You must use database type ''Other''. Then you have complete control over the connection. For MySQL the database driver is ''com.mysql.jdbc.Driver'' and connection string is ''jdbc:mysql://server/database''. You can add other parameters after the conection string, in this case we want to specify ''zeroDateTimeBehavior'' so use connection string ''jdbc:mysql://server/database?zeroDateTimeBehavior=convertToNull''. Remember to replace ''server'' and ''database'' with your database IP address and database name respectively.

← Older revision		Revision as of 18:25, 8 May 2008
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−	Wandora has a feature to import any relational database. ~~Information in the~~ database ~~will be converted into~~ topic ~~map format and then imported~~.	+	Wandora has a feature to import any relational database. Feature introduces a general conversion from SQL database to topic maps.

	== Using the database import tool ==		== Using the database import tool ==

@@ Line 3: / Line 3: @@
 == Using the database import tool ==
-Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is configured allready or create a new database entry and fill in appropriate connection details.
+Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is already configured or create a new database entry and fill in appropriate connection details.
 After selecting the database the tool will show the database schema with options on how to process each column. You can ignore some columns by unchecking the include check box. To ignore a complete table, uncheck all its columns. You can also choose to make topics from column values instead of making occurrences (see conversion details below). You can also choose which column will be used as topic base name.

@@ Line 3: / Line 3: @@
 == Using the database import tool ==
-Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is configured allready or create a new database entry and fill in appropriate connection details. After selecting the database the import process will start. Note that the import process may take anywhere from seconds to hours depending on the size of the database.
+Database conversion is done with the '''[[GenericDatabaseExtractor|Database Extractor]]''' tool found in '''File > Extract''' menu. After launching the tool, it will ask for the database to import. Either select the database if it is configured allready or create a new database entry and fill in appropriate connection details.
 == Postprocessing after conversion ==
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 Values of each normal column, that is column that is not a reference to some other (or same) table, is converted into either an occurrence or a new topic which is then associated with the topic representing the row. Creating topics for column values is natural when the value is shared by many rows, for example when the value represents a year. Creating occurrences is better suited for situations where most or all rows have unique values and creating separate topics would only make the topic map more complex without offering any additional linkage between topics.
 Columns that reference some other column in another or same table are converted into associations. This is the natural thing to do as the referenced row is also a topic and the reference associates these two topics (rows). '''Note:''' Current version of Wandora does not support database schemas where several columns together reference another row.