io.r2dbc.spi

Interface RowMetadata

public interface RowMetadata

Represents the metadata for a row of the results returned from a query. Metadata for columns can be either retrieved by specifying a column name or the column index. Columns are numbered from 0. Column names do not necessarily reflect the column names how they are in the underlying tables but rather how columns are represented (e.g. aliased) in the result.

Method Summary

Modifier and Type	Method and Description
ColumnMetadata	getColumnMetadata(Object identifier) Returns the ColumnMetadata for one column in this row.
Iterable<? extends ColumnMetadata>	getColumnMetadatas() Returns the ColumnMetadata for all columns in this row.
Collection<String>	getColumnNames() Returns an unmodifiable collection of column names.

Method Detail

getColumnMetadata

ColumnMetadata getColumnMetadata(Object identifier)

Returns the ColumnMetadata for one column in this row.

Parameters:

identifier - the identifier of the column. Can be either the column index starting at 0 or column name. Column names are case insensitive. When a get method is called with a column name and several columns have the same name, then the value of the first matching column will be returned.

Returns:

the ColumnMetadata for one column in this row

Throws:

IllegalArgumentException - if identifier is null or not supported

NoSuchElementException - if there is no column with the name identifier

ArrayIndexOutOfBoundsException - if the identifier is a index and it is less than zero or greater than the number of available columns.

getColumnMetadatas

Iterable<? extends ColumnMetadata> getColumnMetadatas()

Returns the ColumnMetadata for all columns in this row.

Returns:

the ColumnMetadata for all columns in this row

getColumnNames

Collection<String> getColumnNames()

Returns an unmodifiable collection of column names.

Any attempts to modify the returned collection, whether direct or via its iterator, result in an UnsupportedOperationException.

The iteration order of the column names depends on the actual query result. Column names may appear multiple times if the result specifies multiple columns with the same name. Lookups through Collection.contains(Object) are case-insensitive. Drivers may enhance comparison sorting rules with escape characters to enforce a particular mode of comparison when querying for presence/absence of a column.

Returns:

the column names.