Module java.sql
Package java.sql

Interface ResultSetMetaData

  • All Superinterfaces:
    Wrapper
    All Known Subinterfaces:
    RowSetMetaData
    All Known Implementing Classes:
    RowSetMetaDataImpl
    public interface ResultSetMetaData
extends Wrapper
    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

      Fields 
      Modifier and Type Field Description
      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

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      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 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.
      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.
      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

        static final int columnNoNulls
        The constant indicating that a column does not allow NULL values.
        See Also:
        Constant Field Values

      • columnNullable

        static final int columnNullable
        The constant indicating that a column allows NULL values.
        See Also:
        Constant Field Values

      • columnNullableUnknown

        static final int columnNullableUnknown
        The constant indicating that the nullability of a column's values is unknown.
        See Also:
        Constant Field Values

    • Method Detail

      • getColumnCount

        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

        boolean isAutoIncrement​(int column)
                 throws SQLException
        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

        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

        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

        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

        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

        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

        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

        String getColumnLabel​(int column)
               throws 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.
        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

        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

        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

        int getPrecision​(int column)
          throws 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.
        Parameters:
        column - the first column is 1, the second is 2, ...
        Returns:
        precision
        Throws:
        SQLException - if a database access error occurs

      • getScale

        int getScale​(int column)
      throws 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.
        Parameters:
        column - the first column is 1, the second is 2, ...
        Returns:
        scale
        Throws:
        SQLException - if a database access error occurs

      • getTableName

        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

        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:
        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

        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

        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

        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

        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

        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

        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.

        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