org.firebirdsql.jdbc

Class FBResultSetMetaData

java.lang.Object

org.firebirdsql.jdbc.AbstractFieldMetaData

org.firebirdsql.jdbc.FBResultSetMetaData

All Implemented Interfaces:

java.sql.ResultSetMetaData, java.sql.Wrapper, FirebirdResultSetMetaData

public class FBResultSetMetaData
extends AbstractFieldMetaData
implements FirebirdResultSetMetaData

An object that can be used to get information about the types and properties of the columns in a ResultSet object.

Author:

David Jencks, Mark Rotteveel

Nested Class Summary

Nested classes/interfaces inherited from class org.firebirdsql.jdbc.AbstractFieldMetaData

AbstractFieldMetaData.ExtendedFieldInfo, AbstractFieldMetaData.FieldKey

Field Summary

Fields inherited from interface java.sql.ResultSetMetaData

columnNoNulls, columnNullable, columnNullableUnknown

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FBResultSetMetaData(RowDescriptor rowDescriptor, FBConnection connection) Creates a new FBResultSetMetaData instance.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getCatalogName(int column) Gets the designated column's table's catalog name.
java.lang.String	getColumnClassName(int column) Returns the fully-qualified name of the Java class whose instances are manufactured if the method ResultSet.getObject is called to retrieve a value from the column.
int	getColumnCount() Returns the number of columns in this ResultSet object.
int	getColumnDisplaySize(int column) Indicates the designated column's normal maximum width in characters.
java.lang.String	getColumnLabel(int column) Gets the designated column's suggested title for use in printouts and displays.
java.lang.String	getColumnName(int column) Get the designated column's name.
int	getColumnType(int column) Retrieves the designated column's SQL type.
java.lang.String	getColumnTypeName(int column) Retrieves the designated column's database-specific type name.
protected java.util.Map<AbstractFieldMetaData.FieldKey,AbstractFieldMetaData.ExtendedFieldInfo>	getExtendedFieldInfo(FBConnection connection) This method retrieves extended information from the system tables in a database.
int	getPrecision(int column) Get the designated column's specified column size.
int	getScale(int column) Gets the designated column's number of digits to right of the decimal point.
java.lang.String	getSchemaName(int column) Get the designated column's table's schema.
java.lang.String	getTableAlias(int column) Gets the designated column's table alias.
java.lang.String	getTableName(int column) Gets the designated column's table name.
boolean	isAutoIncrement(int column) Indicates whether the designated column is automatically numbered.
boolean	isCaseSensitive(int column) Indicates whether a column's case matters.
boolean	isCurrency(int column) Indicates whether the designated column is a cash value.
boolean	isDefinitelyWritable(int column) Indicates whether a write on the designated column will definitely succeed.
int	isNullable(int column) Indicates the nullability of values in the designated column.
boolean	isReadOnly(int column) Indicates whether the designated column is definitely not writable.
boolean	isSearchable(int column) Indicates whether the designated column can be used in a where clause.
boolean	isSigned(int column) Indicates whether values in the designated column are signed numbers.
boolean	isWritable(int column) Indicates whether it is possible for a write on the designated column to succeed.

Methods inherited from class org.firebirdsql.jdbc.AbstractFieldMetaData

estimateFixedPrecision, getExtFieldInfo, getFieldClassName, getFieldCount, getFieldDescriptor, getFieldType, getFieldTypeName, getPrecisionInternal, getRowDescriptor, getScaleInternal, isSignedInternal, isWrapperFor, unwrap

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.sql.Wrapper

isWrapperFor, unwrap

Constructor Detail

FBResultSetMetaData

protected FBResultSetMetaData(RowDescriptor rowDescriptor,
                              FBConnection connection)
                       throws java.sql.SQLException

Creates a new FBResultSetMetaData instance.

Parameters:

rowDescriptor - a row descriptor

connection - a FBConnection value

Throws:

java.sql.SQLException - if an error occurs

TODO Need another constructor for metadata from constructed result set, where we supply the ext field info.

Method Detail

getColumnCount

public int getColumnCount()
                   throws java.sql.SQLException

Returns the number of columns in this ResultSet object.

Specified by:

getColumnCount in interface java.sql.ResultSetMetaData

Returns:

the number of columns

Throws:

java.sql.SQLException - if a database access error occurs

isAutoIncrement

public boolean isAutoIncrement(int column)
                        throws java.sql.SQLException

Indicates whether the designated column is automatically numbered.

The current implementation always returns false.

Specified by:

isAutoIncrement in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isCaseSensitive

public boolean isCaseSensitive(int column)
                        throws java.sql.SQLException

Indicates whether a column's case matters.

The current implementation always returns true.

Specified by:

isCaseSensitive in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isSearchable

public boolean isSearchable(int column)
                     throws java.sql.SQLException

Indicates whether the designated column can be used in a where clause.

Specified by:

isSearchable in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isCurrency

public boolean isCurrency(int column)
                   throws java.sql.SQLException

Indicates whether the designated column is a cash value.

Specified by:

isCurrency in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isNullable

public int isNullable(int column)
               throws java.sql.SQLException

Indicates the nullability of values in the designated column.

Specified by:

isNullable in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

the nullability status of the given column; one of columnNoNulls, columnNullable or columnNullableUnknown

Throws:

java.sql.SQLException - if a database access error occurs

isSigned

public boolean isSigned(int column)
                 throws java.sql.SQLException

Indicates whether values in the designated column are signed numbers.

Specified by:

isSigned in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

getColumnDisplaySize

public int getColumnDisplaySize(int column)
                         throws java.sql.SQLException

Indicates the designated column's normal maximum width in characters.

Specified by:

getColumnDisplaySize in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

the normal maximum number of characters allowed as the width of the designated column

Throws:

java.sql.SQLException - if a database access error occurs

getColumnLabel

public java.lang.String getColumnLabel(int column)
                                throws java.sql.SQLException

Gets the designated column's suggested title for use in printouts and displays. The suggested title is usually specified by the SQL AS clause. If a SQL AS is not specified, the value returned from getColumnLabel will be the same as the value returned by the getColumnName method.

Specified by:

getColumnLabel in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

the suggested column title

Throws:

java.sql.SQLException - if a database access error occurs

getColumnName

public java.lang.String getColumnName(int column)
                               throws java.sql.SQLException

Get the designated column's name.

Specified by:

getColumnName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

column name

Throws:

java.sql.SQLException - if a database access error occurs

getSchemaName

public java.lang.String getSchemaName(int column)
                               throws java.sql.SQLException

Get the designated column's table's schema.

Firebird has no schemas. This method always returns the empty string.

Specified by:

getSchemaName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

schema name or "" if not applicable

Throws:

java.sql.SQLException - if a database access error occurs

getPrecision

public int getPrecision(int column)
                 throws java.sql.SQLException

Get the designated column's specified column size.

For numeric data, this is the maximum precision. For character data, this is the length in characters. For datetime datatypes, this is the length in characters of the String representation (assuming the maximum allowed precision of the fractional seconds component). For binary data, this is the length in bytes. For the ROWID datatype, this is the length in bytes. 0 is returned for data types where the column size is not applicable.

NOTE For NUMERIC and DECIMAL we attempt to retrieve the exact precision from the metadata, if this is not possible (eg the column is dynamically defined in the query), the reported precision is the maximum precision allowed by the underlying storage data type.

Specified by:

getPrecision in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

precision

Throws:

java.sql.SQLException - if a database access error occurs

getScale

public int getScale(int column)
             throws java.sql.SQLException

Gets the designated column's number of digits to right of the decimal point. 0 is returned for data types where the scale is not applicable.

Specified by:

getScale in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

scale

Throws:

java.sql.SQLException - if a database access error occurs

getTableName

public java.lang.String getTableName(int column)
                              throws java.sql.SQLException

Gets the designated column's table name.

Specified by:

getTableName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

table name or "" if not applicable

Throws:

java.sql.SQLException - if a database access error occurs

getTableAlias

public java.lang.String getTableAlias(int column)
                               throws java.sql.SQLException

Description copied from interface: FirebirdResultSetMetaData

Gets the designated column's table alias.

Specified by:

getTableAlias in interface FirebirdResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

table alias or "" if not applicable

Throws:

java.sql.SQLException - if a database access error occurs

getCatalogName

public java.lang.String getCatalogName(int column)
                                throws java.sql.SQLException

Gets the designated column's table's catalog name.

Firebird has no catalogs. This method always returns the empty string.

Specified by:

getCatalogName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

the name of the catalog for the table in which the given column appears or "" if not applicable

Throws:

java.sql.SQLException - if a database access error occurs

getColumnType

public int getColumnType(int column)
                  throws java.sql.SQLException

Retrieves the designated column's SQL type.

Specified by:

getColumnType in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

SQL type from java.sql.Types

Throws:

java.sql.SQLException - if a database access error occurs

See Also:

Types

getColumnTypeName

public java.lang.String getColumnTypeName(int column)
                                   throws java.sql.SQLException

Retrieves the designated column's database-specific type name.

Specified by:

getColumnTypeName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

type name used by the database. If the column type is a user-defined type, then a fully-qualified type name is returned.

Throws:

java.sql.SQLException - if a database access error occurs

isReadOnly

public boolean isReadOnly(int column)
                   throws java.sql.SQLException

Indicates whether the designated column is definitely not writable.

The current implementation always returns false.

Specified by:

isReadOnly in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isWritable

public boolean isWritable(int column)
                   throws java.sql.SQLException

Indicates whether it is possible for a write on the designated column to succeed.

The current implementation always returns true.

Specified by:

isWritable in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

isDefinitelyWritable

public boolean isDefinitelyWritable(int column)
                             throws java.sql.SQLException

Indicates whether a write on the designated column will definitely succeed.

The current implementation always returns true.

Specified by:

isDefinitelyWritable in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

java.sql.SQLException - if a database access error occurs

getColumnClassName

public java.lang.String getColumnClassName(int column)
                                    throws java.sql.SQLException

Returns the fully-qualified name of the Java class whose instances are manufactured if the method ResultSet.getObject is called to retrieve a value from the column.

ResultSet.getObject may return a subclass of the class returned by this method.

Specified by:

getColumnClassName in interface java.sql.ResultSetMetaData

Parameters:

column - the first column is 1, the second is 2, ...

Returns:

the fully-qualified name of the class in the Java programming language that would be used by the method ResultSet.getObject to retrieve the value in the specified column. This is the class name used for custom mapping.

Throws:

java.sql.SQLException - if a database access error occurs

getExtendedFieldInfo

protected java.util.Map<AbstractFieldMetaData.FieldKey,AbstractFieldMetaData.ExtendedFieldInfo> getExtendedFieldInfo(FBConnection connection)
                                                                                                              throws java.sql.SQLException

Description copied from class: AbstractFieldMetaData

This method retrieves extended information from the system tables in a database. Since this method is expensive, use it with care.

Specified by:

getExtendedFieldInfo in class AbstractFieldMetaData

Returns:

mapping between AbstractFieldMetaData.FieldKey instances and AbstractFieldMetaData.ExtendedFieldInfo instances, or an empty Map if the metadata implementation does not support extended info.

Throws:

java.sql.SQLException - if a database error occurs while obtaining extended field information.