io.r2dbc.spi

Interface Row

public interface Row

Represents a row returned from a database query. Values from 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.

Column names used as input to getter methods 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. The column name option is designed to be used when column names are used in the SQL query that generated the result set. Columns that are not explicitly named in the query should be referenced through column indexes.

For maximum portability, result columns within each Row should be read in left-to-right order, and each column should be read only once.

get(String) and get(int) without specifying a target type returns a suitable value representation. The R2DBC specification contains a mapping table that shows default mappings between database types and Java types. Specifying a target type, the R2DBC driver attempts to convert the value to the target type.

A row is invalidated after consumption in the mapping function.

The number, type and characteristics of columns are described through RowMetadata

Method Summary

Modifier and Type	Method and Description
default Object	get(int index) Returns the value for a column in this row using the default type mapping.
<T> T	get(int index, Class<T> type) Returns the value for a column in this row.
default Object	get(String name) Returns the value for a column in this row using the default type mapping.
<T> T	get(String name, Class<T> type) Returns the value for a column in this row.

Method Detail

get

@Nullable
default Object get(int index)

Returns the value for a column in this row using the default type mapping. The default implementation of this method calls get(int, Class) passing Object as the type to allow the implementation to make the loosest possible match.

Parameters:

index - the index of the column starting at 0

Returns:

the value for a column in this row. Value can be null.

get

@Nullable
<T> T get(int index,
                    Class<T> type)

Returns the value for a column in this row. Use Object to allow the implementation to make the loosest possible match.

Type Parameters:

T - the type of the item being returned.

Parameters:

index - the index of the column starting at 0

type - the type of item to return. This type must be assignable to, and allows for variance.

Returns:

the value for a column in this row. Value can be null.

Throws:

IllegalArgumentException - if type is null

get

@Nullable
default Object get(String name)

Returns the value for a column in this row using the default type mapping. The default implementation of this method calls get(String, Class) passing Object as the type in order to allow the implementation to make the loosest possible match.

Parameters:

name - the name of the column

Returns:

the value for a column in this row. Value can be null.

Throws:

IllegalArgumentException - if name is null

get

@Nullable
<T> T get(String name,
                    Class<T> type)

Returns the value for a column in this row. Use Object to allow the implementation to make the loosest possible match.

Type Parameters:

T - the type of the item being returned.

Parameters:

name - the name of the column

type - the type of item to return. This type must be assignable to, and allows for variance.

Returns:

the value for a column in this row. Value can be null.

Throws:

IllegalArgumentException - if name or type is null