resultsetmetadata.java

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/*
   Copyright (C) 2002 MySQL AB

      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.

      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.

      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */
package com.mysql.jdbc;

import java.sql.SQLException;
import java.sql.Types;


/**
 * A ResultSetMetaData object can be used to find out about the types and
 * properties of the columns in a ResultSet
 *
 * @see java.sql.ResultSetMetaData
 * @author Mark Matthews
 * @version $Id: ResultSetMetaData.java,v 1.12.2.6 2004/02/18 16:04:58 mmatthew Exp $
 */
public class ResultSetMetaData implements java.sql.ResultSetMetaData {
    Field[] fields;

    /**
            * Initialise for a result with a tuple set and
     * a field descriptor set
     *
     * @param fields the array of field descriptors

     */
    public ResultSetMetaData(Field[] fields) {
        this.fields = fields;
    }

    /**
     * Is the column automatically numbered (and thus read-only)
     *
     * MySQL Auto-increment columns are not read only,
     * so to conform to the spec, this method returns false.
     *
     * @param column the first column is 1, the second is 2...
     * @return true if so
     * @throws java.sql.SQLException if a database access error occurs
     */
    public boolean isAutoIncrement(int column) throws java.sql.SQLException {
        Field f = getField(column);

        return f.isAutoIncrement();
    }

    /**
     * Does a column's case matter? ASSUMPTION: Any field that is
     * not obviously case insensitive is assumed to be case sensitive
     *
     * @param column the first column is 1, the second is 2...
     * @return true if so
     * @throws java.sql.SQLException if a database access error occurs
     */
    public boolean isCaseSensitive(int column) throws java.sql.SQLException {
    	Field field = getField(column);
    	
        int sqlType = field.getSQLType();

        switch (sqlType) {
        case Types.BIT:
        case Types.TINYINT:
        case Types.SMALLINT:
        case Types.INTEGER:
        case Types.BIGINT:
        case Types.FLOAT:
        case Types.REAL:
        case Types.DOUBLE:
        case Types.DATE:
        case Types.TIME:
        case Types.TIMESTAMP:
            return false;
        	
        case Types.CHAR:
        case Types.VARCHAR:
        	
        	return field.isBinary();
        	    	
        default:
            return true;
        }
    }

    /**
     * What's a column's table's catalog name?
     *
     * @param column the first column is 1, the second is 2...
     * @return catalog name, or "" if not applicable
     * @throws java.sql.SQLException if a database access error occurs
     */
    public String getCatalogName(int column) throws java.sql.SQLException {
        Field f = getField(column);

        String database = f.getDatabaseName();

        return (database == null) ? "" : database;
    }

    //--------------------------JDBC 2.0-----------------------------------

    /**
     * JDBC 2.0
     *
     * <p>Return the fully qualified name of the Java class whose instances
     * are manufactured if ResultSet.getObject() is called to retrieve a value
     * from the column.  ResultSet.getObject() may return a subClass of the
     * class returned by this method.
     *
     * @param column the column number to retrieve information for
     * @return the fully qualified name of the Java class whose instances
     * are manufactured if ResultSet.getObject() is called to retrieve a value
     * from the column.
     *
     * @throws SQLException if an error occurs
     */
    public String getColumnClassName(int column) throws SQLException {
        Field f = getField(column);

        // From JDBC-3.0 spec
        //
        //  JDBC Type Java Object Type
        //
        // CHAR 			String
        // VARCHAR 			String
        // LONGVARCHAR 		String
        // NUMERIC 			java.math.BigDecimal
        // DECIMAL 			java.math.BigDecimal
        // BIT 				Boolean
        // BOOLEAN 			Boolean
        // TINYINT 			Integer
        // SMALLINT 		Integer
        // INTEGER 			Integer
        // BIGINT 			Long
        // REAL 			Float
        // FLOAT 			Double
        // DOUBLE 			Double
        // BINARY 			byte[]
        // VARBINARY 		byte[]
        // LONGVARBINARY 	byte[]
        // DATE 			java.sql.Date
        // TIME 			java.sql.Time
        // TIMESTAMP 		java.sql.Timestamp
        // DISTINCT 		Object type of underlying type
        // CLOB 			Clob
        // BLOB 			Blob
        // ARRAY 			Array
        // STRUCT 			Struct or SQLData
        // REF 				Ref
        // DATALINK 		java.net.URL
        // JAVA_OBJECT 		underlying Java class
         
        switch (f.getSQLType()) {
        case Types.BIT:
        case Types.BOOLEAN:
            return "java.lang.Boolean";

        case Types.TINYINT:

            return "java.lang.Integer";
           
        case Types.SMALLINT:

            return "java.lang.Integer";

        case Types.INTEGER:

            if (f.isUnsigned()) {
                return "java.lang.Long";
            } else {
                return "java.lang.Integer";
            }

        case Types.BIGINT:
        	
            return "java.lang.Long";

        case Types.DECIMAL:
        case Types.NUMERIC:
        	
            return "java.math.BigDecimal";

        case Types.REAL:
        
            return "java.lang.Float";
        
        case Types.FLOAT:
        case Types.DOUBLE:
        	
            return "java.lang.Double";

        case Types.CHAR:
        case Types.VARCHAR:
        case Types.LONGVARCHAR:
        	
            return "java.lang.String";

        case Types.BINARY:
        case Types.VARBINARY:
        case Types.LONGVARBINARY:

            if (!f.isBlob()) {
                return "java.lang.String";
            } else if (!f.isBinary()) {
                return "java.lang.String";
            } else {
                return "[B";
            }

        case Types.DATE:
        	
            return "java.sql.Date";

        case Types.TIME:
        	
            return "java.sql.Time";

        case Types.TIMESTAMP:
        	
            return "java.sql.Timestamp";

        default:
        	
            return "java.lang.Object";
        }
    }

    /**
     * Whats the number of columns in the ResultSet?
     *
     * @return the number
     * @throws java.sql.SQLException if a database access error occurs
     */
    public int getColumnCount() throws java.sql.SQLException {
        return fields.length;
    }

    /**
     * What is the column's normal maximum width in characters?
     *
     * @param column the first column is 1, the second is 2, etc.
     * @return the maximum width
     * @throws java.sql.SQLException if a database access error occurs
     */
    public int getColumnDisplaySize(int column) throws java.sql.SQLException {
        return getField(column).getLength();
    }

    /**
     * What is the suggested column title for use in printouts and
     * displays?
     *
     * @param column the first column is 1, the second is 2, etc.
     * @return the column label
     * @throws java.sql.SQLException if a database access error occurs
     */
    public String getColumnLabel(int column) throws java.sql.SQLException {
        return getColumnName(column);
    }

    /**
     * What's a column's name?
     *
     * @param column the first column is 1, the second is 2, etc.
     * @return the column name
     * @throws java.sql.SQLException if a databvase access error occurs
     */
    public String getColumnName(int column) throws java.sql.SQLException {
        return getField(column).getName();
    }

    /**
     * What is a column's SQL Type? (java.sql.Type int)
     *
     * @param column the first column is 1, the second is 2, etc.
     * @return the java.sql.Type value
     * @throws java.sql.SQLException if a database access error occurs
     * @see java.sql.Types
     */
    public int getColumnType(int column) throws java.sql.SQLException {
        return getField(column).getSQLType();
    }

    /**
     * Whats is the column's data source specific type name?
     *
     * @param column the first column is 1, the second is 2, etc.
     * @return the type name