type CheckConstraint struct {
	Name       string
	Constraint string // length(phone) >= 10
	*Field
}

func (chk *CheckConstraint) GetName() string { return chk.Name }

func (chk *CheckConstraint) Build() (sql string, vars []interface{}) {
	return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
}

// ParseCheckConstraints parse schema check constraints

						if rel.Field.IgnoreMigration {
							continue
						}
						if constraint := rel.ParseConstraint(); constraint != nil &&
							constraint.Schema == stmt.Schema && !queryTx.Migrator().HasConstraint(value, constraint.Name) {
							if err := execTx.Migrator().CreateConstraint(value, constraint.Name); err != nil {
								return err
							}
						}
					}
				}

	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
	if constraint.OnDelete != "" {
		sql += " ON DELETE " + constraint.OnDelete
	}

	if constraint.OnUpdate != "" {
		sql += " ON UPDATE " + constraint.OnUpdate
	}

	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
	for _, field := range constraint.ForeignKeys {
		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})

        <constraint name="__context__" within="" contains="" />
        <constraint name="TYPE" within="" contains="" />
        <constraint name="ARR" nameOfExprType=".*\[\]" within="" contains="" />
        <constraint name="RES" nameOfExprType="boolean" exprTypeWithinHierarchy="true" within="" contains="" />
        <constraint name="ITEM" within="" contains="" />
        <constraint name="TARGET" within="" contains="" />

        return delegate.parseVersionRange(range);
    }

    @Override
    public VersionConstraint parseVersionConstraint(String constraint) throws InvalidVersionSpecificationException {
        return delegate.parseVersionConstraint(constraint);
    }

	// ErrDuplicatedKey occurs when there is a unique key constraint violation
	ErrDuplicatedKey = errors.New("duplicated key not allowed")
	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation
	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
	// ErrCheckConstraintViolated occurs when there is a check constraint violation
	ErrCheckConstraintViolated = errors.New("violates check constraint")

     */
    @Nonnull
    VersionRange parseVersionRange(@Nonnull String range);

    /**
     * Parses the specified version constraint specification, for example "1.0" or "[1.0,2.0)".
     *
     * @param constraint the range specification to parse, must not be {@code null}
     * @return the parsed version constraint, never {@code null}
     * @throws VersionParserException if the range specification violates the syntax rules of this scheme
     */

    }

    @Override
    public VersionConstraint parseVersionConstraint(String constraint) {
        requireNonNull(constraint, "constraint");
        return new DefaultVersionConstraint(versionScheme, constraint);
    }

    static class DefaultVersion implements Version {
        private final VersionScheme versionScheme;

        return modelVersionParser.parseVersionRange(range);
    }

    @Override
    public VersionConstraint parseVersionConstraint(String constraint) {
        return modelVersionParser.parseVersionConstraint(constraint);
    }

    @Override
    public boolean isSnapshot(String version) {
        return modelVersionParser.isSnapshot(version);
    }

		}

		constraints := user.ParseUniqueConstraints()
		if len(constraints) != 1 {
			t.Fatalf("failed to find unique constraint, got %v", constraints)
		}

		for key := range constraints {
			if len(key) != 63 {
				t.Errorf("failed to find unique constraint, got %v", constraints)
			}
		}
	})

	t.Run("naming strategy", func(t *testing.T) {