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JDBC Reference
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Reference Manual |
java.sql.DatabaseMetaDataStored Prepared Statements for DatabaseMetaData QueriesThe JDBC driver has built-in queries that it uses to supply the results of the JDBC DatabaseMetaData methods that supply information about the Cloudscape system. These methods are useful for applications working with generic DBMSs, such as database tools, not Cloudscape-specific applications, which can query system catalogs directly. The cloudscape.jdbc.metadataStoredPreparedStatements property configures Cloudscape's built-in JDBC driver to take advantage of stored prepared statements to avoid preparing these queries each time an application starts up. JDBC DatabaseMetaData queries are duplicated in every Cloudscape database even if a single Cloudscape system manages several databases. With this property, you have the option of having Cloudscape create and store the statements as needed (dynamically) or all at once when the database is created. For more information, see cloudscape.jdbc.metadataStoredPreparedStatements in Tuning Cloudscape. DatabaseMetaData Result SetsDatabaseMetaData result sets do not close the result sets of other statements, even when auto-commit is set to true. DatabaseMetaData result sets are closed if a user performs any other action on a JDBC object that causes an automatic commit to occur. If you need the DatabaseMetaData result sets to be accessible while executing other actions that would cause automatic commits, turn off auto-commit with setAutoCommit(false). getProcedureColumnsCloudscape does not have stored procedures, which are procedures written in SQL dialect. Instead, Cloudscape allows you to call Java methods within SQL-J statements. It also allows you to define aliases for static Java methods; these are called method aliases (see CREATE METHOD ALIAS statement). Cloudscape returns information about the parameters and return values of these method aliases in the getProcedureColumns call. If the corresponding Java method is overloaded, it returns information about each signature separately. getProcedureColumns returns a ResultSet. Each row describes a single parameter or return value. Parameters to getProcedureColumnsThe JDBC API defines the following parameters for this method call:
Columns in the ResultSet Returned by getProcedureColumnsColumns in the ResultSet returned by getProcedureColumns are as described by the API. Further details for some specific columns:
NEW: Implementation of the DatabaseMetaData.getProcedureColumns method is new in Version 3.6. DatabaseMetaData Functionality Not SupportedIn the current release, Cloudscape does not provide all of the DatabaseMetaData functionality. The following JDBC requests result in empty result sets, in the format required by the JDBC API: Cloudscape does not implement privileges, and thus has no information to provide for these calls. getBestRowIdentifier looks for identifiers in this order:
Because of this last choice, it will always find a set of columns that identify a row. However, if there are duplicate rows in the table, use of all columns may not necessarily identify a unique row in the table. |
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![]() Cloudscape Version 3.6 For information about Cloudscape technical support, go to: www.cloudscape.com/support/.Copyright © 1998, 1999, 2000 Informix Software, Inc. All rights reserved. |