dbffiledatabasemetadata.java

TinySQL是一个轻量级的纯java数据库引擎

/*
 * dbfFileDatabaseMetaData.java
 */

package com.sqlmagic.tinysql;

/**
 * Comprehensive information about the database as a whole.
 *
 * Many of the methods here return lists of information in
 * the form of ResultSet objects.
 * You can use the normal ResultSet methods such as getString and getInt
 * to retrieve the data from these ResultSets.  If a given form of
 * metadata is not available, these methods should throw an SQLException.
 *
 * Some of these 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 a null ref,
 * that argument's criteria will be dropped from the search.
 *
 * An SQLException will be thrown if a driver does not support a meta
 * data method.  In the case of methods that return a ResultSet,
 * either a ResultSet (which may be empty) is returned or a
 * SQLException is thrown.
 *
 * $Author: davis $
 * $Date: 2004/12/18 21:30:57 $
 * $Revision: 1.1 $
 *
 */
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Types;
import java.util.Vector;
import java.io.File;


/**
dBase read/write access <br>
@author Brian Jepson <[e-mail]>
@author Marcel Ruff <[e-mail]> Added DatabaseMetaData with JDK 2 support
@author Thomas Morgner <[e-mail]> Changed DatabaseMetaData to use java.sql.Types.
*/
public class dbfFileDatabaseMetaData extends tinySQLDatabaseMetaData {
  private final String emptyString = "";

    public dbfFileDatabaseMetaData(Connection connection) {
        super(connection);
    }

    public String getDatabaseProductName()
    {
        return "tinySQL";
    }
    public String getDatabaseProductVersion()
    {
        return tinySQLGlobals.VERSION;
    }
    String getDataDir()
    {
        String url = ((dbfFileConnection)getConnection()).url;
        if (url.length() <= 13)
            return null;

        String dataDir = url.substring(13);
        return dataDir;
    }

    /**
     * Gets a description of all the standard SQL types supported by
     * this database. They are ordered by DATA_TYPE and then by how
     * closely the data type maps to the corresponding JDBC SQL type.
     *
     * <P>Each type description has the following columns:
     *  <OL>
     *  <LI><B>TYPE_NAME</B> String => Type name
     *  <LI><B>DATA_TYPE</B> short => SQL data type from java.sql.Types
     *  <LI><B>PRECISION</B> int => maximum precision
     *  <LI><B>LITERAL_PREFIX</B> String => prefix used to quote a literal
     *      (may be null)
     *  <LI><B>LITERAL_SUFFIX</B> String => suffix used to quote a literal
            (may be null)
     *  <LI><B>CREATE_PARAMS</B> String => parameters used in creating
     *      the type (may be null)
     *  <LI><B>NULLABLE</B> short => can you use NULL for this type?
     *      <UL>
     *      <LI> typeNoNulls - does not allow NULL values
     *      <LI> typeNullable - allows NULL values
     *      <LI> typeNullableUnknown - nullability unknown
     *      </UL>
     *  <LI><B>CASE_SENSITIVE</B> boolean=> is it case sensitive?
     *  <LI><B>SEARCHABLE</B> short => can you use "WHERE" based on this type:
     *      <UL>
     *      <LI> typePredNone - No support
     *      <LI> typePredChar - Only supported with WHERE .. LIKE
     *      <LI> typePredBasic - Supported except for WHERE .. LIKE
     *      <LI> typeSearchable - Supported for all WHERE ..
     *      </UL>
     *  <LI><B>UNSIGNED_ATTRIBUTE</B> boolean => is it unsigned?
     *  <LI><B>FIXED_PREC_SCALE</B> boolean => can it be a money value?
     *  <LI><B>AUTO_INCREMENT</B> boolean => can it be used for an
     *      auto-increment value?
     *  <LI><B>LOCAL_TYPE_NAME</B> String => localized version of type name
     *      (may be null)
     *  <LI><B>MINIMUM_SCALE</B> short => minimum scale supported
     *  <LI><B>MAXIMUM_SCALE</B> short => maximum scale supported
     *  <LI><B>SQL_DATA_TYPE</B> int => unused
     *  <LI><B>SQL_DATETIME_SUB</B> int => unused
     *  <LI><B>NUM_PREC_RADIX</B> int => usually 2 or 10
     *  </OL>
     *
     * @return ResultSet - each row is a SQL type description
     * @exception SQLException if a database access error occurs
     */
      public ResultSet getTypeInfo() throws SQLException {
        tsResultSet jrs = new tsResultSet();

        tsColumn jsc = new tsColumn("TYPE_NAME");
        jsc.type = Types.CHAR;
        jsc.size = 10;
        jrs.addColumn (jsc);

        jsc = new tsColumn("DATA_TYPE");
        jsc.type = Types.INTEGER;
        jsc.size = 6;
        jrs.addColumn (jsc);

        jsc = new tsColumn("PRECISION");
        jsc.type = Types.INTEGER;
        jsc.size = 8;
        jrs.addColumn (jsc);

        jsc = new tsColumn("LITERAL_PREFIX");
        jsc.type = Types.CHAR;
        jsc.size = 1;
        jrs.addColumn (jsc);

        jsc = new tsColumn("LITERAL_SUFFIX");
        jsc.type = Types.CHAR;
        jsc.size = 1;
        jrs.addColumn (jsc);

        jsc = new tsColumn("CREATE_PARAMS");
        jsc.type = Types.CHAR;
        jsc.size = 20;
        jrs.addColumn (jsc);

        jsc = new tsColumn("NULLABLE");
        jsc.type = Types.INTEGER;
        jsc.size = 6;
        jrs.addColumn (jsc);

        jsc = new tsColumn("CASE_SENSITIVE");
        jsc.type = Types.BIT;
        jsc.size = 1;
        jrs.addColumn (jsc);

        jsc = new tsColumn("SEARCHABLE");
        jsc.type = Types.INTEGER;
        jsc.size = 6;
        jrs.addColumn (jsc);

         /*
         *  <LI><B>UNSIGNED_ATTRIBUTE</B> boolean => is it unsigned?
         *  <LI><B>FIXED_PREC_SCALE</B> boolean => can it be a money value?
         *  <LI><B>AUTO_INCREMENT</B> boolean => can it be used for an
         *      auto-increment value?
         *  <LI><B>LOCAL_TYPE_NAME</B> String => localized version of type name
         *      (may be null)
         *  <LI><B>MINIMUM_SCALE</B> short => minimum scale supported
         *  <LI><B>MAXIMUM_SCALE</B> short => maximum scale supported
         *  <LI><B>NUM_PREC_RADIX</B> int => usually 2 or 10
         */


        // NOTE: the Hashtable in tsRow expects always a String as its value!
        //       so i use the toString() method here
        //       Perhaps in future the real type should be pushed into the Hashtable?

        tsRow record = new tsRow();
        record.put("TYPE_NAME", dbfFile.typeToLiteral(Types.CHAR));    // "CHAR", String
        record.put("DATA_TYPE", new Integer(Types.CHAR).toString());
        record.put("PRECISION", new Integer(254).toString());
        record.put("LITERAL_PREFIX", "\"");
        record.put("LITERAL_SUFFIX", "\"");
        record.put("CREATE_PARAMS", new Integer(0).toString());
        record.put("NULLABLE", new Integer(typeNullableUnknown).toString());
        record.put("CASE_SENSITIVE", "N");
        record.put("SEARCHABLE", new Integer(typePredBasic).toString());
        jrs.addRow (record) ;

        record = new tsRow();
        record.put("TYPE_NAME", dbfFile.typeToLiteral(Types.FLOAT));    // "FLOAT", double
        record.put("DATA_TYPE", new Integer(Types.FLOAT).toString());
        record.put("PRECISION", new Integer(19).toString());
        record.put("LITERAL_PREFIX", emptyString);
        record.put("LITERAL_SUFFIX", emptyString);
        record.put("CREATE_PARAMS", new Integer(0).toString());
        record.put("NULLABLE", new Integer(typeNullableUnknown).toString());
        record.put("CASE_SENSITIVE", "N");
        record.put("SEARCHABLE", new Integer(typePredBasic).toString());
        jrs.addRow (record) ;

        record = new tsRow();
        record.put("TYPE_NAME", dbfFile.typeToLiteral(Types.BIT));     // "CHAR", boolean "YyNnTtFf"
        record.put("DATA_TYPE", new Integer(Types.BIT).toString());
        record.put("PRECISION", new Integer(1).toString());
        record.put("LITERAL_PREFIX", "\"");
        record.put("LITERAL_SUFFIX", "\"");
        record.put("CREATE_PARAMS", new Integer(0).toString());
        record.put("NULLABLE", new Integer(typeNullableUnknown).toString());
        record.put("CASE_SENSITIVE", "N");
        record.put("SEARCHABLE", new Integer(typePredBasic).toString());
        jrs.addRow (record) ;

        record = new tsRow();
        record.put("TYPE_NAME", dbfFile.typeToLiteral(Types.INTEGER));     // "INT", unsigned long
        record.put("DATA_TYPE", new Integer(Types.INTEGER).toString());
        record.put("PRECISION", new Integer(19).toString());
        record.put("LITERAL_PREFIX", emptyString);
        record.put("LITERAL_SUFFIX", emptyString);
        record.put("CREATE_PARAMS", new Integer(0).toString());
        record.put("NULLABLE", new Integer(typeNullableUnknown).toString());
        record.put("CASE_SENSITIVE", "N");
        record.put("SEARCHABLE", new Integer(typePredBasic).toString());
        jrs.addRow (record) ;

        record = new tsRow();
        record.put("TYPE_NAME", dbfFile.typeToLiteral(Types.DATE));     // "DATE", date
        record.put("DATA_TYPE", new Integer(Types.DATE).toString());
        record.put("PRECISION", new Integer(8).toString());
        record.put("LITERAL_PREFIX", "\"");
        record.put("LITERAL_SUFFIX", "\"");
        record.put("CREATE_PARAMS", new Integer(0).toString());
        record.put("NULLABLE", new Integer(typeNullableUnknown).toString());
        record.put("CASE_SENSITIVE", "N");
        record.put("SEARCHABLE", new Integer(typePredBasic).toString());
        jrs.addRow (record) ;

        return new tinySQLResultSet(jrs, (tinySQLStatement)null);
      }
/*
 * Gets a description of tables available in a catalog.
 *
 * Only table descriptions matching the catalog, schema, table
 * name and type criteria are returned.  They are ordered by
 * TABLE_TYPE, TABLE_SCHEM and TABLE_NAME.
 *
 * Each table description has the following columns:
 * 
 * TABLE_CAT String => table catalog (may be null)
 * TABLE_SCHEM String => table schema (may be null)
 * TABLE_NAME String => table name
 * TABLE_TYPE String => table type.  Typical types are "TABLE",
 *      "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY",
 *      "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
 * REMARKS String => explanatory comment on the table
 *
 * Note: Some databases may not return information for
 * all tables.
 *
 * @param catalog a catalog name; "" retrieves those without a
 * catalog; null means drop catalog name from the selection criteria
 * THIS VALUE IS IGNORED
 * @param schemaPattern THIS VALUE IS IGNORED
 * @param tableNamePattern a table name pattern, 磏ull