java.sql
Interface ResultSetMetaData

public interface ResultSetMetaData

An object that can be used to get information about the types and properties of the columns in a ResultSet object. The following code fragment creates the ResultSet object rs, creates the ResultSetMetaData object rsmd, and uses rsmd to find out how many columns rs has and whether the first column in rs can be used in a WHERE clause.

     ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM TABLE2");
     ResultSetMetaData rsmd = rs.getMetaData();
     int numberOfColumns = rsmd.getColumnCount();
     boolean b = rsmd.isSearchable(1);

 

Field Summary

static int	columnNoNulls The constant indicating that a column does not allow NULL values.
static int	columnNullable The constant indicating that a column allows NULL values.
static int	columnNullableUnknown The constant indicating that the nullability of a column's values is unknown.

Method Summary

String	getCatalogName(int column) Gets the designated column's table's catalog name.
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.
String	getColumnLabel(int column) Gets the designated column's suggested title for use in printouts and displays.
String	getColumnName(int column) Get the designated column's name.
int	getColumnType(int column) Retrieves the designated column's SQL type.
String	getColumnTypeName(int column) Retrieves the designated column's database-specific type name.
int	getPrecision(int column) Get the designated column's number of decimal digits.
int	getScale(int column) Gets the designated column's number of digits to right of the decimal point.
String	getSchemaName(int column) Get the designated column's table's schema.
String	getTableName(int column) Gets the designated column's table name.
boolean	isAutoIncrement(int column) Indicates whether the designated column is automatically numbered, thus read-only.
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.

Field Detail

columnNoNulls

public static final int columnNoNulls

The constant indicating that a column does not allow NULL values.

columnNullable

public static final int columnNullable

The constant indicating that a column allows NULL values.

columnNullableUnknown

public static final int columnNullableUnknown

The constant indicating that the nullability of a column's values is unknown.

Method Detail

getColumnCount

public int getColumnCount()
                   throws SQLException

Returns the number of columns in this ResultSet object.

Returns:

the number of columns

Throws:

SQLException - if a database access error occurs

isAutoIncrement

public boolean isAutoIncrement(int column)
                        throws SQLException

Indicates whether the designated column is automatically numbered, thus read-only.

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isCaseSensitive

public boolean isCaseSensitive(int column)
                        throws SQLException

Indicates whether a column's case matters.

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isSearchable

public boolean isSearchable(int column)
                     throws SQLException

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

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isCurrency

public boolean isCurrency(int column)
                   throws SQLException

Indicates whether the designated column is a cash value.

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isNullable

public int isNullable(int column)
               throws SQLException

Indicates the nullability of values in the designated column.

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:

SQLException - if a database access error occurs

isSigned

public boolean isSigned(int column)
                 throws SQLException

Indicates whether values in the designated column are signed numbers.

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

getColumnDisplaySize

public int getColumnDisplaySize(int column)
                         throws SQLException

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

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:

SQLException - if a database access error occurs

getColumnLabel

public String getColumnLabel(int column)
                      throws SQLException

Gets the designated column's suggested title for use in printouts and displays.

Parameters:

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

Returns:

the suggested column title

Throws:

SQLException - if a database access error occurs

getColumnName

public String getColumnName(int column)
                     throws SQLException

Get the designated column's name.

Parameters:

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

Returns:

column name

Throws:

SQLException - if a database access error occurs

getSchemaName

public String getSchemaName(int column)
                     throws SQLException

Get the designated column's table's schema.

Parameters:

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

Returns:

schema name or "" if not applicable

Throws:

SQLException - if a database access error occurs

getPrecision

public int getPrecision(int column)
                 throws SQLException

Get the designated column's number of decimal digits.

Parameters:

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

Returns:

precision

Throws:

SQLException - if a database access error occurs

getScale

public int getScale(int column)
             throws SQLException

Gets the designated column's number of digits to right of the decimal point.

Parameters:

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

Returns:

scale

Throws:

SQLException - if a database access error occurs

getTableName

public String getTableName(int column)
                    throws SQLException

Gets the designated column's table name.

Parameters:

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

Returns:

table name or "" if not applicable

Throws:

SQLException - if a database access error occurs

getCatalogName

public String getCatalogName(int column)
                      throws SQLException

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

Parameters:

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

Returns:

column name or "" if not applicable

Throws:

SQLException - if a database access error occurs

getColumnType

public int getColumnType(int column)
                  throws SQLException

Retrieves the designated column's SQL type.

Parameters:

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

Returns:

SQL type from java.sql.Types

Throws:

SQLException - if a database access error occurs

See Also:

Types

getColumnTypeName

public String getColumnTypeName(int column)
                         throws SQLException

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

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:

SQLException - if a database access error occurs

isReadOnly

public boolean isReadOnly(int column)
                   throws SQLException

Indicates whether the designated column is definitely not writable.

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isWritable

public boolean isWritable(int column)
                   throws SQLException

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

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

isDefinitelyWritable

public boolean isDefinitelyWritable(int column)
                             throws SQLException

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

Parameters:

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

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

getColumnClassName

public String getColumnClassName(int column)
                          throws 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.

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:

SQLException - if a database access error occurs

Since:

1.2

See Also:

What Is in the JDBC 2.0 API