Known Indirect Subclasses |
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);
Constant Summary
int | columnNoNulls | The constant indicating that a
column does not allow NULL values. |
int | columnNullable | The constant indicating that a
column allows NULL values. |
int | columnNullableUnknown | The constant indicating that the nullability of a column's values is unknown. |
Public Method Summary
abstract String |
getCatalogName(int column)
Gets the designated column's table's catalog name.
|
abstract String |
getColumnClassName(int column)
Returns the fully-qualified name of the Java class whose instances
are manufactured if the method |
abstract int |
getColumnCount()
Returns the number of columns in this
ResultSet object. |
abstract int |
getColumnDisplaySize(int column)
Indicates the designated column's normal maximum width in characters.
|
abstract String |
getColumnLabel(int column)
Gets the designated column's suggested title for use in printouts and
displays.
|
abstract String |
getColumnName(int column)
Get the designated column's name.
|
abstract int |
getColumnType(int column)
Retrieves the designated column's SQL type.
|
abstract String |
getColumnTypeName(int column)
Retrieves the designated column's database-specific type name.
|
abstract int |
getPrecision(int column)
Get the designated column's specified column size.
|
abstract int |
getScale(int column)
Gets the designated column's number of digits to right of the decimal point.
|
abstract String |
getSchemaName(int column)
Get the designated column's table's schema.
|
abstract String |
getTableName(int column)
Gets the designated column's table name.
|
abstract boolean |
isAutoIncrement(int column)
Indicates whether the designated column is automatically numbered.
|
abstract boolean |
isCaseSensitive(int column)
Indicates whether a column's case matters.
|
abstract boolean |
isCurrency(int column)
Indicates whether the designated column is a cash value.
|
abstract boolean |
isDefinitelyWritable(int column)
Indicates whether a write on the designated column will definitely succeed.
|
abstract int |
isNullable(int column)
Indicates the nullability of values in the designated column.
|
abstract boolean |
isReadOnly(int column)
Indicates whether the designated column is definitely not writable.
|
abstract boolean |
isSearchable(int column)
Indicates whether the designated column can be used in a where clause.
|
abstract boolean |
isSigned(int column)
Indicates whether values in the designated column are signed numbers.
|
abstract boolean |
isWritable(int column)
Indicates whether it is possible for a write on the designated column to succeed.
|
Inherited Method Summary
Constants
public static final int columnNoNulls
The constant indicating that a
column does not allow NULL
values.
public static final int columnNullable
The constant indicating that a
column allows NULL
values.
public static final int columnNullableUnknown
The constant indicating that the nullability of a column's values is unknown.
Public Methods
public abstract String getCatalogName (int column)
Gets the designated column's table's catalog name.
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
SQLException | if a database access error occurs |
---|
public abstract 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. ResultSet.getObject
may return a subclass of the
class returned by this method.
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
SQLException | if a database access error occurs |
---|
public abstract int getColumnCount ()
Returns the number of columns in this ResultSet
object.
Returns
- the number of columns
Throws
SQLException | if a database access error occurs |
---|
public abstract int getColumnDisplaySize (int column)
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 |
---|
public abstract String getColumnLabel (int column)
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.
Parameters
column | the first column is 1, the second is 2, ... |
---|
Returns
- the suggested column title
Throws
SQLException | if a database access error occurs |
---|
public abstract String getColumnName (int column)
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 |
---|
public abstract int getColumnType (int column)
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
public abstract String getColumnTypeName (int column)
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 |
---|
public abstract int getPrecision (int column)
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.
Parameters
column | the first column is 1, the second is 2, ... |
---|
Returns
- precision
Throws
SQLException | if a database access error occurs |
---|
public abstract int getScale (int column)
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.
Parameters
column | the first column is 1, the second is 2, ... |
---|
Returns
- scale
Throws
SQLException | if a database access error occurs |
---|
public abstract String getSchemaName (int column)
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 |
---|
public abstract String getTableName (int column)
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 |
---|
public abstract boolean isAutoIncrement (int column)
Indicates whether the designated column is automatically numbered.
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 |
---|
public abstract boolean isCaseSensitive (int column)
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 |
---|
public abstract boolean isCurrency (int column)
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 |
---|
public abstract boolean isDefinitelyWritable (int column)
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 |
---|
public abstract int isNullable (int column)
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
orcolumnNullableUnknown
Throws
SQLException | if a database access error occurs |
---|
public abstract boolean isReadOnly (int column)
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 |
---|
public abstract boolean isSearchable (int column)
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 |
---|
public abstract boolean isSigned (int column)
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 |
---|
public abstract boolean isWritable (int column)
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 |
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