com.google.cloud.spring.data.spanner.core.mapping

Annotation Type Column

@Documented
 @Target(value=FIELD)
 @Retention(value=RUNTIME)
public @interface Column

Annotation for a SpannerPersistentProperty that allows specifying the column name instead of deriving it from the field's name.

Since:

1.1

Author:

Ray Tsang, Chengyuan Zhao

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	name The custom name of the column in the Spanner table, which can differ from the name of the field which it annotates.
boolean	nullable If the column's schema should be NOT NULL when generating a schema based on an entity class.
boolean	spannerCommitTimestamp This setting takes effect when the entity in which it appears is used to generate schema DDL.
TypeCode	spannerType Optionally directly specify the column type in Cloud Spanner.
long	spannerTypeMaxLength The maximum length of the column in Cloud Spanner terms.

Element Detail

name

public abstract String name

The custom name of the column in the Spanner table, which can differ from the name of the field which it annotates.

Returns:

the name of the column in the Spanner table

Default:

""

spannerTypeMaxLength

public abstract long spannerTypeMaxLength

The maximum length of the column in Cloud Spanner terms. For example, for STRING columns this refers to the number of characters. For BYTES columns this refers to the number of bytes. This setting is only used when generating schema from an entity class. A setting of less than 0 indicates an unlimited maximum length.

Returns:

the maximum length for the column

Default:

-1L

nullable

public abstract boolean nullable

If the column's schema should be NOT NULL when generating a schema based on an entity class.

Returns:

false if the column should be NOT NULL in generated DDL. true otherwise.

Default:

true

spannerType

public abstract TypeCode spannerType

Optionally directly specify the column type in Cloud Spanner. For ARRAY columns this refers to type of the item the array holds. If this is not specified then it is inferred from the Java property type.

Returns:

The user-specified column item type.

Default:

com.google.spanner.v1.TypeCode.TYPE_CODE_UNSPECIFIED

spannerCommitTimestamp

public abstract boolean spannerCommitTimestamp

This setting takes effect when the entity in which it appears is used to generate schema DDL. If true, then the column corresponding to the annotated property will be auto-populated with the latest Cloud Spanner TrueTime commit timestamp of the row. false for all other usage and columns.

Returns:

true for auto-populating commit timestamp. false otherwise.

Default:

false