Interface ResultSetMetaData
- All Superinterfaces:
Wrapper
- All Known Subinterfaces:
RowSetMetaData
- All Known Implementing Classes:
RowSetMetaDataImpl
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);
- Since:
- 1.1
-
Field Summary
Modifier and TypeFieldDescriptionstatic final int
The constant indicating that a column does not allowNULL
values.static final int
The constant indicating that a column allowsNULL
values.static final int
The constant indicating that the nullability of a column's values is unknown. -
Method Summary
Modifier and TypeMethodDescriptiongetCatalogName
(int column) Gets the designated column's table's catalog name.getColumnClassName
(int column) Returns the fully-qualified name of the Java class whose instances are manufactured if the methodResultSet.getObject
is called to retrieve a value from the column.int
Returns the number of columns in thisResultSet
object.int
getColumnDisplaySize
(int column) Indicates the designated column's normal maximum width in characters.getColumnLabel
(int column) Gets the designated column's suggested title for use in printouts and displays.getColumnName
(int column) Get the designated column's name.int
getColumnType
(int column) Retrieves the designated column's SQL type.getColumnTypeName
(int column) Retrieves the designated column's database-specific type name.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. 0 is returned for data types where the scale is not applicable.getSchemaName
(int column) Get the designated column's table's schema.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 declared in interface java.sql.Wrapper
isWrapperFor, unwrap
-
Field Details
-
columnNoNulls
static final int columnNoNullsThe constant indicating that a column does not allowNULL
values.- See Also:
-
columnNullable
static final int columnNullableThe constant indicating that a column allowsNULL
values.- See Also:
-
columnNullableUnknown
static final int columnNullableUnknownThe constant indicating that the nullability of a column's values is unknown.- See Also:
-
-
Method Details
-
getColumnCount
Returns the number of columns in thisResultSet
object.- Returns:
- the number of columns
- Throws:
SQLException
- if a database access error occurs
-
isAutoIncrement
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
-
isCaseSensitive
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
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
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
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
-
isSigned
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
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
Gets the designated column's suggested title for use in printouts and displays. The suggested title is usually specified by the SQLAS
clause. If a SQLAS
is not specified, the value returned fromgetColumnLabel
will be the same as the value returned by thegetColumnName
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
-
getColumnName
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
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
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
-
getScale
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
-
getTableName
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
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
-
getColumnType
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:
-
getColumnTypeName
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
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
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
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
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- Since:
- 1.2
-