abstractjdbc1databasemetadata.java

来自「PostgreSQL7.4.6 for Linux」· Java 代码 · 共 2,128 行 · 第 1/5 页

package org.postgresql.jdbc1;


import java.sql.*;
import java.util.*;
import org.postgresql.core.BaseStatement;
import org.postgresql.core.Field;
import org.postgresql.core.Encoding;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;
import org.postgresql.Driver;

public abstract class AbstractJdbc1DatabaseMetaData
{

	private static final String keywords = "abort,acl,add,aggregate,append,archive," +
										   "arch_store,backward,binary,boolean,change,cluster," +
										   "copy,database,delimiter,delimiters,do,extend," +
										   "explain,forward,heavy,index,inherits,isnull," +
										   "light,listen,load,merge,nothing,notify," +
										   "notnull,oids,purge,rename,replace,retrieve," +
										   "returns,rule,recipe,setof,stdin,stdout,store," +
										   "vacuum,verbose,version";

	protected AbstractJdbc1Connection connection; // The connection association
	protected Encoding encoding;

	// These define various OID's. Hopefully they will stay constant.
	protected static final int iVarcharOid = 1043;	// OID for varchar
	protected static final int iBoolOid = 16; // OID for bool
	protected static final int iInt2Oid = 21; // OID for int2
	protected static final int iInt4Oid = 23; // OID for int4
	protected static final int VARHDRSZ = 4;	// length for int4

	private int NAMEDATALEN = 0;	// length for name datatype
	private int INDEX_MAX_KEYS = 0; // maximum number of keys in an index.

	protected int getMaxIndexKeys() throws SQLException {
		if (INDEX_MAX_KEYS == 0) {
			String from;
			if (connection.haveMinimumServerVersion("7.3")) {
				from = "pg_catalog.pg_namespace n, pg_catalog.pg_type t1, pg_catalog.pg_type t2 WHERE t1.typnamespace=n.oid AND n.nspname='pg_catalog' AND ";
			} else {
				from = "pg_type t1, pg_type t2 WHERE ";
			}
			String sql = "SELECT t1.typlen/t2.typlen FROM "+from+" t1.typelem=t2.oid AND t1.typname='oidvector'";
			ResultSet rs = connection.createStatement().executeQuery(sql);
			if (!rs.next()) {
				throw new PSQLException("postgresql.unexpected", PSQLState.UNEXPECTED_ERROR);
			}
			INDEX_MAX_KEYS = rs.getInt(1);
			rs.close();
		}
		return INDEX_MAX_KEYS;
	}

	protected int getMaxNameLength() throws SQLException {
		if (NAMEDATALEN == 0) {
			String sql;
			if (connection.haveMinimumServerVersion("7.3")) {
				sql = "SELECT t.typlen FROM pg_catalog.pg_type t, pg_catalog.pg_namespace n WHERE t.typnamespace=n.oid AND t.typname='name' AND n.nspname='pg_catalog'";
			} else {
				sql = "SELECT typlen FROM pg_type WHERE typname='name'";
			}
			ResultSet rs = connection.createStatement().executeQuery(sql);
			if (!rs.next()) {
				throw new PSQLException("postgresql.unexpected", PSQLState.UNEXPECTED_ERROR);
			}
			NAMEDATALEN = rs.getInt("typlen");
			rs.close();
		}
		return NAMEDATALEN - 1;
	}

	public AbstractJdbc1DatabaseMetaData(AbstractJdbc1Connection conn)
	{
		this.connection = conn;
		try {
			this.encoding = conn.getEncoding();
		}
		catch (SQLException sqle) {
			this.encoding = Encoding.defaultEncoding();
		}

	}

	/*
	 * Can all the procedures returned by getProcedures be called
	 * by the current user?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean allProceduresAreCallable() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("allProceduresAreCallable");
		return true;		// For now...
	}

	/*
	 * Can all the tables returned by getTable be SELECTed by
	 * the current user?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean allTablesAreSelectable() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("allTablesAreSelectable");
		return true;		// For now...
	}

	/*
	 * What is the URL for this database?
	 *
	 * @return the url or null if it cannott be generated
	 * @exception SQLException if a database access error occurs
	 */
	public String getURL() throws SQLException
	{
		String url = connection.getURL();
		if (Driver.logDebug)
			Driver.debug("getURL " + url);
		return url;
	}

	/*
	 * What is our user name as known to the database?
	 *
	 * @return our database user name
	 * @exception SQLException if a database access error occurs
	 */
	public String getUserName() throws SQLException
	{
		String userName = connection.getUserName();
		if (Driver.logDebug)
			Driver.debug("getUserName " + userName);
		return userName;
	}

	/*
	 * Is the database in read-only mode?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean isReadOnly() throws SQLException
	{
		boolean isReadOnly = connection.isReadOnly();
		if (Driver.logDebug)
			Driver.debug("isReadOnly " + isReadOnly);
		return isReadOnly;
	}

	/*
	 * Are NULL values sorted high?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean nullsAreSortedHigh() throws SQLException
	{
		boolean nullSortedHigh = connection.haveMinimumServerVersion("7.2");
		if (Driver.logDebug)
			Driver.debug("nullsAreSortedHigh " + nullSortedHigh);
		return nullSortedHigh;
	}

	/*
	 * Are NULL values sorted low?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean nullsAreSortedLow() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("nullsAreSortedLow false");
		return false;
	}

	/*
	 * Are NULL values sorted at the start regardless of sort order?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean nullsAreSortedAtStart() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("nullsAreSortedAtStart false");
		return false;
	}

	/*
	 * Are NULL values sorted at the end regardless of sort order?
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean nullsAreSortedAtEnd() throws SQLException
	{
		boolean nullsAreSortedAtEnd = ! connection.haveMinimumServerVersion("7.2");
		if (Driver.logDebug)
			Driver.debug("nullsAreSortedAtEnd " + nullsAreSortedAtEnd);
		return nullsAreSortedAtEnd;
	}

	/*
	 * What is the name of this database product - we hope that it is
	 * PostgreSQL, so we return that explicitly.
	 *
	 * @return the database product name
	 * @exception SQLException if a database access error occurs
	 */
	public String getDatabaseProductName() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("getDatabaseProductName PostgresSQL");
		return "PostgreSQL";
	}

	/*
	 * What is the version of this database product.
	 *
	 * @return the database version
	 * @exception SQLException if a database access error occurs
	 */
	public String getDatabaseProductVersion() throws SQLException
	{
		String versionNumber = connection.getDBVersionNumber();
		if (Driver.logDebug)
			Driver.debug("getDatabaseProductVersion " + versionNumber);
		return versionNumber;
	}

	/*
	 * What is the name of this JDBC driver?  If we don't know this
	 * we are doing something wrong!
	 *
	 * @return the JDBC driver name
	 * @exception SQLException why?
	 */
	public String getDriverName() throws SQLException
	{
		String driverName = "PostgreSQL Native Driver";
		if (Driver.logDebug)
			Driver.debug("getDriverName" + driverName);
		return driverName;
	}

	/*
	 * What is the version string of this JDBC driver?	Again, this is
	 * static.
	 *
	 * @return the JDBC driver name.
	 * @exception SQLException why?
	 */
	public String getDriverVersion() throws SQLException
	{
		String driverVersion = Driver.getVersion();
		if (Driver.logDebug)
			Driver.debug("getDriverVersion " + driverVersion);
		return driverVersion;
	}

	/*
	 * What is this JDBC driver's major version number?
	 *
	 * @return the JDBC driver major version
	 */
	public int getDriverMajorVersion()
	{
		int majorVersion = connection.this_driver.getMajorVersion();
		if (Driver.logDebug)
			Driver.debug("getMajorVersion " + majorVersion);
		return majorVersion;
	}

	/*
	 * What is this JDBC driver's minor version number?
	 *
	 * @return the JDBC driver minor version
	 */
	public int getDriverMinorVersion()
	{
		int minorVersion = connection.this_driver.getMinorVersion();
		if (Driver.logDebug)
			Driver.debug("getMinorVersion " + minorVersion);
		return minorVersion;
	}

	/*
	 * Does the database store tables in a local file?	No - it
	 * stores them in a file on the server.
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean usesLocalFiles() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("usesLocalFiles " + false);
		return false;
	}

	/*
	 * Does the database use a file for each table?  Well, not really,
	 * since it doesnt use local files.
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean usesLocalFilePerTable() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("usesLocalFilePerTable " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case unquoted SQL identifiers
	 * as case sensitive and as a result store them in mixed case?
	 * A JDBC-Compliant driver will always return false.
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean supportsMixedCaseIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("supportsMixedCaseIdentifiers " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case unquoted SQL identifiers as
	 * case insensitive and store them in upper case?
	 *
	 * @return true if so
	 */
	public boolean storesUpperCaseIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("storesUpperCaseIdentifiers " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case unquoted SQL identifiers as
	 * case insensitive and store them in lower case?
	 *
	 * @return true if so
	 */
	public boolean storesLowerCaseIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("storesLowerCaseIdentifiers " + true);
		return true;
	}

	/*
	 * Does the database treat mixed case unquoted SQL identifiers as
	 * case insensitive and store them in mixed case?
	 *
	 * @return true if so
	 */
	public boolean storesMixedCaseIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("storesMixedCaseIdentifiers " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case quoted SQL identifiers as
	 * case sensitive and as a result store them in mixed case?  A
	 * JDBC compliant driver will always return true.
	 *
	 * @return true if so
	 * @exception SQLException if a database access error occurs
	 */
	public boolean supportsMixedCaseQuotedIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("supportsMixedCaseQuotedIdentifiers " + true);
		return true;
	}

	/*
	 * Does the database treat mixed case quoted SQL identifiers as
	 * case insensitive and store them in upper case?
	 *
	 * @return true if so
	 */
	public boolean storesUpperCaseQuotedIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("storesUpperCaseQuotedIdentifiers " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case quoted SQL identifiers as case
	 * insensitive and store them in lower case?
	 *
	 * @return true if so
	 */
	public boolean storesLowerCaseQuotedIdentifiers() throws SQLException
	{
		if (Driver.logDebug)
			Driver.debug("storesLowerCaseQuotedIdentifiers " + false);
		return false;
	}

	/*
	 * Does the database treat mixed case quoted SQL identifiers as case
	 * insensitive and store them in mixed case?
	 *
	 * @return true if so
	 */
	public boolean storesMixedCaseQuotedIdentifiers() throws SQLException
	{
		if (Driver.logDebug)