Class AddUniqueConstraintCommand

  • All Implemented Interfaces:

    public class AddUniqueConstraintCommand
    extends Object
    implements AlterTableCommand
    Represents a unique constraint on a set of columns. Beware columns that allow null values! On SQL Server and Oracle, nulls are distinct values (and so constraints over them will prevent two rows containing nulls in those columns). On MySQL nulls will cause the constraint to be ignored, no matter the values in any other constrained columns. On DB2, nullable columns cannot have unique constraints at all.
    • Constructor Detail

      • AddUniqueConstraintCommand

        public AddUniqueConstraintCommand​(String constraintName,
                                          Collection<String> columns)
    • Method Detail

      • getCommandName

        public String getCommandName()
        Specified by:
        getCommandName in interface AlterTableCommand
        The keyword/name of the current command for the current database (e.g. altering a column is "alter column" on PostgreSQL and "modify" on MySQL.
      • getCommandParameters

        public String getCommandParameters()
        Specified by:
        getCommandParameters in interface AlterTableCommand
        The part that comes after the command name. E.g. "colname set not null" which would be after "alter column colname set not null"