Module is.codion.framework.domain
Package is.codion.framework.domain.entity.attribute

Interface ColumnDefinition<T>

Type Parameters:
T - the underlying type
All Superinterfaces:
AttributeDefinition<T>, ValueAttributeDefinition<T>
public sealed interface ColumnDefinition<T> extends ValueAttributeDefinition<T>
Specifies an attribute definition based on a table column.

ColumnDefinition extends ValueAttributeDefinition with column-specific configuration such as primary key properties, SQL expressions, insertable/updatable flags, and database value conversion logic.

Column definitions are created through the column builder API: 

 interface Product {
     EntityType TYPE = DOMAIN.entityType("store.product");

     Column<Integer> ID = TYPE.integerColumn("id");
     Column<String> NAME = TYPE.stringColumn("name");
     Column<BigDecimal> PRICE = TYPE.bigDecimalColumn("price");
     Column<LocalDateTime> CREATED_DATE = TYPE.localDateTimeColumn("created_date");
 }

 Product.TYPE.define(
         // Primary key with auto-generation
         Product.ID.define()
             .primaryKey()
             .generator(Generator.identity()),

         // Required string column with length constraint
         Product.NAME.define()
             .column()
             .nullable(false)
             .maximumLength(100),

         // Decimal column with precision and range validation
         Product.PRICE.define()
             .column()
             .nullable(false)
             .minimum(BigDecimal.ZERO)
             .maximum(new BigDecimal("99999.99"))
             .fractionDigits(2),

         // Audit column (database-managed)
         Product.CREATED_DATE.define()
             .column()
             .insertable(false)  // Not included in INSERT
             .updatable(false)   // Not included in UPDATE
             .withDefault(true)) // Database provides a default value
     .build();
See Also:

  • Method Details

    • attribute

      Column<T> attribute()
      Description copied from interface: AttributeDefinition
      The Attribute this definition is based on, should be unique within an Entity. By default, the Attribute.name() serves as column name for database columns.
      Specified by:
      attribute in interface AttributeDefinition<T>
      Returns:
      the attribute this definition is based on

    • name

      String name()
      Note: returns null when used in a remote connection context.
      Returns:
      the column name

    • expression

      String expression()
      Note: returns null when used in a remote connection context.
      Returns:
      the column expression to use when selecting or the column name if no expression has been set

    • type

      int type()
      Returns:
      the sql data type of the underlying column (Types.

    • generated

      boolean generated()
      Returns:
      true if the value of this column is generated.
      See Also:

    • generator

      Column.Generator<T> generator()
      Returns:
      the Column.Generator used to populate the value of this column
      Throws:
      IllegalStateException - in case a generator is not available
      See Also:

    • converter

      <C> Column.Converter<C,T> converter()
      Note: returns null when used in a remote connection context.
      Type Parameters:
      C - the colum value type
      Returns:
      the Column.Converter for this column.

    • keyIndex

      int keyIndex()
      Returns:
      this columns zero based index in the primary key, -1 if this column is not part of a primary key

    • primaryKey

      boolean primaryKey()
      Returns:
      true if this column is part of a primary key

    • groupBy

      boolean groupBy()
      Returns:
      true if this column should be grouped by

    • aggregate

      boolean aggregate()
      Returns:
      true if this column is based on an aggregate function

    • selected

      boolean selected()
      Returns:
      true if this column should be selected by default

    • insertable

      boolean insertable()
      Specifies whether this column is insertable
      Returns:
      true if this column is insertable

    • updatable

      boolean updatable()
      Indicates whether this column is updatable
      Returns:
      true if this column is updatable

    • readOnly

      boolean readOnly()
      Returns:
      true if this column is neither insertable nor updatable.

    • withDefault

      boolean withDefault()
      Returns:
      true if the underlying database column has a default value

    • searchable

      boolean searchable()
      Returns:
      true if this column should be included when searching by string

    • get

      @Nullable T get(ResultSet resultSet, int index) throws SQLException
      Fetches a value for this column from a ResultSet
      Parameters:
      resultSet - the ResultSet
      index - this columns index in the result
      Returns:
      a single value fetched from the given ResultSet
      Throws:
      SQLException - in case of an exception

    • get

      @Nullable T get(ResultSet resultSet) throws SQLException
      Fetches a value for this column from a ResultSet by name
      Parameters:
      resultSet - the ResultSet
      Returns:
      a single value fetched from the given ResultSet
      Throws:
      SQLException - in case of an exception

    • set

      void set(PreparedStatement statement, int index, @Nullable T value) throws SQLException
      Sets a parameter for this column in a PreparedStatement
      Parameters:
      statement - the statement
      index - the parameter index
      value - the value to set, may be null
      Throws:
      SQLException - in case of an exception