//----------------------------------------------------------------------------
//
// Module: SimpleTextResultSetMetaData.java
//
// Description: Implementation of the JDBC ResultSetMetaData interface
//
// Author: Karl Moss
//
// Copyright: (C) 1996,1997 Karl Moss. All rights reserved.
// You may study, use, modify and distribute this example
// for any purpose, provided that this copyright notice
// appears in all copies. This example is provided WITHOUT
// WARRANTY either expressed or implied.
//----------------------------------------------------------------------------
package jdbc.SimpleText;
//----------------------------------------------------------------------------
// A ResultSetMetaData object can be used to find out about the types
// and properties of the columns in a ResultSet.
//----------------------------------------------------------------------------
// NOTE - this is an implementation of the JDBC API version 1.20
//---------------------------------------------------------------------------
import java.sql.*;
import java.util.Hashtable;
public class SimpleTextResultSetMetaData
extends SimpleTextObject
implements ResultSetMetaData
{
//------------------------------------------------------------------------
// initialize
//------------------------------------------------------------------------
public void initialize(
Hashtable columns,
boolean readOnly)
{
inMemoryColumns = columns;
}
//------------------------------------------------------------------------
// getColumnCount - JDBC API
// What's the number of columns in the ResultSet?
//
// Returns the number
//------------------------------------------------------------------------
public int getColumnCount()
throws SQLException
{
return inMemoryColumns.size();
}
//------------------------------------------------------------------------
// isAutoIncrement - JDBC API
// Is the column automatically numbered, thus read-only?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isAutoIncrement(
int column)
throws SQLException
{
// The SimpleText driver does not support auto increment columns
return false;
}
//------------------------------------------------------------------------
// isCaseSensitive - JDBC API
// Does a column's case matter?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isCaseSensitive(
int column)
throws SQLException
{
// Case never matters
return false;
}
//------------------------------------------------------------------------
// isSearchable - JDBC API
// Can the column be used in a where clause?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isSearchable(
int column)
throws SQLException
{
// The SimpleText driver does not support searching
return false;
}
//------------------------------------------------------------------------
// isCurrency - JDBC API
// Is the column a cash value?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isCurrency(
int column)
throws SQLException
{
// The SimpleText driver does not support any currency data types
return false;
}
//------------------------------------------------------------------------
// isNullable - JDBC API
// Can you put a NULL in this column?
//
// column the first column is 1, the second is 2, ...
//
// Returns columnNoNulls, columnNullable or columnNullableUnknown
//------------------------------------------------------------------------
public int isNullable(
int column)
throws SQLException
{
// The SimpleText driver does not support nullable columns
return columnNoNulls;
}
//------------------------------------------------------------------------
// isSigned - JDBC API
// Is the column a signed number?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isSigned(
int column)
throws SQLException
{
// The SimpleText driver does not support signed columns
return false;
}
//------------------------------------------------------------------------
// getColumnDisplaySize
// What's the column's normal max width in chars?
//
// column the first column is 1, the second is 2, ...
//
// Returns max width
//------------------------------------------------------------------------
public int getColumnDisplaySize(
int column)
throws SQLException
{
return (getColumn(column)).displaySize;
}
//------------------------------------------------------------------------
// getColumnLabel - JDBC API
// What's the suggested column title for use in printouts and
// displays?
//
// column the first column is 1, the second is 2, ...
//
// Returns the column label
//------------------------------------------------------------------------
public String getColumnLabel(
int column)
throws SQLException
{
// Use the column name
return getColumnName(column);
}
//------------------------------------------------------------------------
// getColumnName - JDBC API
// What's a column's name?
//
// column the first column is 1, the second is 2, ...
//
// Returns column name
//------------------------------------------------------------------------
public String getColumnName(
int column)
throws SQLException
{
return (getColumn(column)).name;
}
//------------------------------------------------------------------------
// getSchemaName - JDBC API
// What's a column's table's schema?
//
// column the first column is 1, the second is 2, ...
//
// Returns schema name or "" if not applicable
//------------------------------------------------------------------------
public String getSchemaName(
int column)
throws SQLException
{
// The SimpleText driver does not support schemas
return "";
}
//------------------------------------------------------------------------
// getPrecision - JDBC API
// What's a column's number of decimal digits?
//
// column the first column is 1, the second is 2, ...
//
// Returns precision
//------------------------------------------------------------------------
public int getPrecision(
int column)
throws SQLException
{
return (getColumn(column)).precision;
}
//------------------------------------------------------------------------
// getScale - JDBC API
// What's a column's number of digits to right of decimal?
//
// column the first column is 1, the second is 2, ...
//
// Returns scale
//------------------------------------------------------------------------
public int getScale(
int column)
throws SQLException
{
// The SimpleText driver does not support any data types with scale
return 0;
}
//------------------------------------------------------------------------
// getTableName - JDBC API
// What's a column's table name?
//
// Returns table name or "" if not applicable
//------------------------------------------------------------------------
public String getTableName(
int column)
throws SQLException
{
return "";
}
//------------------------------------------------------------------------
// getCatalogName - JDBC API
// What's a column's table's catalog name?
//
// column the first column is 1, the second is 2, ...
//
// Returns column name or "" if not applicable.
//------------------------------------------------------------------------
public String getCatalogName(
int column)
throws SQLException
{
return "";
}
//------------------------------------------------------------------------
// getColumnType - JDBC API
// What's a column's SQL type?
//
// column the first column is 1, the second is 2, ...
//
// Returns SQL type
//------------------------------------------------------------------------
public int getColumnType(
int column)
throws SQLException
{
return (getColumn(column)).type;
}
//------------------------------------------------------------------------
// getColumnTypeName - JDBC API
// What's a column's data source specific type name?
//
// column the first column is 1, the second is 2, ...
//
// Returns type name
//------------------------------------------------------------------------
public String getColumnTypeName(
int column)
throws SQLException
{
return (getColumn(column)).typeName;
}
//------------------------------------------------------------------------
// isReadOnly - JDBC API
// Is a column definitely not writable?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isReadOnly(
int column)
throws SQLException
{
return readOnly;
}
//------------------------------------------------------------------------
// isWritable - JDBC API
// Is it possible for a write on the column to succeed?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isWritable(
int column)
throws SQLException
{
return !isReadOnly(column);
}
//------------------------------------------------------------------------
// isDefinitelyWritable - JDBC API
// Will a write on the column definitely succeed?
//
// column the first column is 1, the second is 2, ...
//
// Returns true if so
//------------------------------------------------------------------------
public boolean isDefinitelyWritable(
int column)
throws SQLException
{
return !isReadOnly(column);
}
//------------------------------------------------------------------------
// getColumn
// Returns the SimpleTextColumn object for the given column number.
// If not found, an exception is thrown
//------------------------------------------------------------------------
protected SimpleTextColumn getColumn(
int col)
throws SQLException
{
SimpleTextColumn column = (SimpleTextColumn)
inMemoryColumns.get(new Integer(col));
if (column == null) {
throw new SQLException("Invalid column number: " + col);
}
return column;
}
// All column information is kept in a Hashtable. This hashtable
// is keyed by the column number, and contains a SimpleTextColumn
// object
protected Hashtable inMemoryColumns;
// Flag indicating whether the connection is read-only
protected boolean readOnly;
}
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