databasemetadata.java

java数据库源代码 请看看啊 提点宝贵的意见

/*
 * @(#)DatabaseMetaData.java	1.52 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */


package java.sql;

/**
 * Comprehensive information about the database as a whole.
 * <P>
 * This interface is implemented by driver vendors to let users know the capabilities
 * of a Database Management System (DBMS) in combination with 
 * the driver based on JDBC<sup><font size=-2>TM</font></sup> technology 
 * ("JDBC driver") that is used with it.  Different relational DBMSs often support
 * different features, implement features in different ways, and use different
 * data types.  In addition, a driver may implement a feature on top of what the 
 * DBMS offers.  Information returned by methods in this interface applies
 * to the capabilities of a particular driver and a particular DBMS working
 * together. Note that as used in this documentation, the term "database" is
 * used generically to refer to both the driver and DBMS.
 * <P>
 * A user for this interface is commonly a tool that needs to discover how to
 * deal with the underlying DBMS.  This is especially true for applications
 * that are intended to be used with more than one DBMS. For example, a tool might use the method 
 * <code>getTypeInfo</code> to find out what data types can be used in a
 * <code>CREATE TABLE</code> statement.  Or a user might call the method
 * <code>supportsCorrelatedSubqueries</code> to see if it is possible to use
 * a correlated subquery or <code>supportsBatchUpdates</code> to see if it is 
 * possible to use batch updates. 
 * <P>
 * Some <code>DatabaseMetaData</code> methods return lists of information
 * in the form of <code>ResultSet</code> objects.
 * Regular <code>ResultSet</code> methods, such as
 * <code>getString</code> and <code>getInt</code>, can be used 
 * to retrieve the data from these <code>ResultSet</code> objects.  If 
 * a given form of metadata is not available, the <code>ResultSet</code>
 * getter methods throw an <code>SQLException</code>.
 * <P>
 * Some <code>DatabaseMetaData</code> methods take arguments that are 
 * String patterns.  These arguments all have names such as fooPattern.  
 * Within a pattern String, "%" means match any substring of 0 or more 
 * characters, and "_" means match any one character. Only metadata 
 * entries matching the search pattern are returned. If a search pattern 
 * argument is set to <code>null</code>, that argument's criterion will 
 * be dropped from the search.
 * <P>
 * A method that gets information about a feature that the driver does not
 * support will throw an <code>SQLException</code>.
 * In the case of methods that return a <code>ResultSet</code>
 * object, either a <code>ResultSet</code> object (which may be empty) is 
 * returned or an <code>SQLException</code> is thrown.
 */
public interface DatabaseMetaData {

    //----------------------------------------------------------------------
    // First, a variety of minor information about the target database.

    /**
     * Retrieves whether the current user can call all the procedures 
     * returned by the method <code>getProcedures</code>.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean allProceduresAreCallable() throws SQLException;

    /**
     * Retrieves whether the current user can use all the tables returned 
     * by the method <code>getTables</code> in a <code>SELECT</code> 
     * statement.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean allTablesAreSelectable() throws SQLException;

    /**
     * Retrieves the URL for this DBMS.
     *
     * @return the URL for this DBMS or <code>null</code> if it cannot be 
     *          generated
     * @exception SQLException if a database access error occurs
     */
    String getURL() throws SQLException;

    /**
     * Retrieves the user name as known to this database.
     *
     * @return the database user name
     * @exception SQLException if a database access error occurs
     */
    String getUserName() throws SQLException;

    /**
     * Retrieves whether this database is in read-only mode.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean isReadOnly() throws SQLException;

    /**
     * Retrieves whether <code>NULL</code> values are sorted high.
     * Sorted high means that <code>NULL</code> values
     * sort higher than any other value in a domain.  In an ascending order,
     * if this method returns <code>true</code>,  <code>NULL</code> values
     * will appear at the end. By contrast, the method 
     * <code>nullsAreSortedAtEnd</code> indicates whether <code>NULL</code> values
     * are sorted at the end regardless of sort order.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean nullsAreSortedHigh() throws SQLException;

    /**
     * Retrieves whether <code>NULL</code> values are sorted low.
     * Sorted low means that <code>NULL</code> values
     * sort lower than any other value in a domain.  In an ascending order,
     * if this method returns <code>true</code>,  <code>NULL</code> values
     * will appear at the beginning. By contrast, the method 
     * <code>nullsAreSortedAtStart</code> indicates whether <code>NULL</code> values
     * are sorted at the beginning regardless of sort order.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean nullsAreSortedLow() throws SQLException;

    /**
     * Retrieves whether <code>NULL</code> values are sorted at the start regardless 
     * of sort order.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean nullsAreSortedAtStart() throws SQLException;

    /**
     * Retrieves whether <code>NULL</code> values are sorted at the end regardless of 
     * sort order.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean nullsAreSortedAtEnd() throws SQLException;

    /**
     * Retrieves the name of this database product.
     *
     * @return database product name
     * @exception SQLException if a database access error occurs
     */
    String getDatabaseProductName() throws SQLException;

    /**
     * Retrieves the version number of this database product.
     *
     * @return database version number
     * @exception SQLException if a database access error occurs
     */
    String getDatabaseProductVersion() throws SQLException;

    /**
     * Retrieves the name of this JDBC driver.
     *
     * @return JDBC driver name
     * @exception SQLException if a database access error occurs
     */
    String getDriverName() throws SQLException;

    /**
     * Retrieves the version number of this JDBC driver as a <code>String</code>.
     *
     * @return JDBC driver version
     * @exception SQLException if a database access error occurs
     */
    String getDriverVersion() throws SQLException;

    /**
     * Retrieves this JDBC driver's major version number.
     *
     * @return JDBC driver major version
     */
    int getDriverMajorVersion();

    /**
     * Retrieves this JDBC driver's minor version number.
     *
     * @return JDBC driver minor version number
     */
    int getDriverMinorVersion();

    /**
     * Retrieves whether this database stores tables in a local file.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean usesLocalFiles() throws SQLException;

    /**
     * Retrieves whether this database uses a file for each table.
     *
     * @return <code>true</code> if this database uses a local file for each table;
     *         <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean usesLocalFilePerTable() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case sensitive and as a result stores them in mixed case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean supportsMixedCaseIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in upper case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesUpperCaseIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in lower case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesLowerCaseIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case unquoted SQL identifiers as
     * case insensitive and stores them in mixed case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesMixedCaseIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case sensitive and as a result stores them in mixed case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    boolean supportsMixedCaseQuotedIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in upper case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesUpperCaseQuotedIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in lower case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesLowerCaseQuotedIdentifiers() throws SQLException;

    /**
     * Retrieves whether this database treats mixed case quoted SQL identifiers as
     * case insensitive and stores them in mixed case.
     *
     * @return <code>true</code> if so; <code>false</code> otherwise 
     * @exception SQLException if a database access error occurs
     */
    boolean storesMixedCaseQuotedIdentifiers() throws SQLException;

    /**
     * Retrieves the string used to quote SQL identifiers.
     * This method returns a space " " if identifier quoting is not supported.
     *
     * @return the quoting string or a space if quoting is not supported
     * @exception SQLException if a database access error occurs
     */
    String getIdentifierQuoteString() throws SQLException;

    /**
     * Retrieves a comma-separated list of all of this database's SQL keywords
     * that are NOT also SQL92 keywords.
     *
     * @return the list of this database's keywords that are not also
     *         SQL92 keywords
     * @exception SQLException if a database access error occurs
     */
    String getSQLKeywords() throws SQLException;

    /**
     * Retrieves a comma-separated list of math functions available with
     * this database.  These are the Open /Open CLI math function names used in 
     * the JDBC function escape clause.
     *
     * @return the list of math functions supported by this database
     * @exception SQLException if a database access error occurs
     */
    String getNumericFunctions() throws SQLException;

    /**
     * Retrieves a comma-separated list of string functions available with
     * this database.  These are the  Open Group CLI string function names used 
     * in the JDBC function escape clause.
     *
     * @return the list of string functions supported by this database 
     * @exception SQLException if a database access error occurs
     */
    String getStringFunctions() throws SQLException;

    /**
     * Retrieves a comma-separated list of system functions available with
     * this database.  These are the  Open Group CLI system function names used 
     * in the JDBC function escape clause.
     *