*
 * <p>The allowed row and column keys must be supplied when the table is created. The table always
 * contains a mapping for every row key / column pair. The value corresponding to a given row and
 * column is null unless another value is provided.
 *
 * <p>The table's size is constant: the product of the number of supplied row keys and the number of

   *
   * <p>The views returned by the {@code Table} methods {@link Table#column}, {@link
   * Table#columnKeySet}, and {@link Table#columnMap} have iterators that don't support {@code
   * remove()}. Otherwise, all optional operations are supported. Null row keys, columns keys, and
   * values are not supported.
   *
   * <p>Lookups by row key are often faster than lookups by column key, because the data is stored

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

	CurrentTable string = "~~~ct~~~" // current table
	Associations string = "~~~as~~~" // associations
)

var (
	currentTable  = Table{Name: CurrentTable}
	PrimaryColumn = Column{Table: CurrentTable, Name: PrimaryKey}
)

// Column quote with name
type Column struct {
	Table string
	Name  string
	Alias string
	Raw   bool
}

// Table quote with name
type Table struct {
	Name  string
	Alias string
	Raw   bool

					}

					if len(selectExpr.Exprs) == 0 {
						selectExpr.Exprs = []clause.Expression{clause.Expr{SQL: "*", Vars: []interface{}{}}}
					}

					partitionBy := clause.CommaExpression{}
					for _, column := range refColumns {
						partitionBy.Exprs = append(partitionBy.Exprs, clause.Expr{SQL: "?", Vars: []interface{}{clause.Column{Name: column.Name}}})
					}

   *
   * <p>The returned map's views have iterators that don't support {@code remove()}.
   */
  @Override
  public Map<R, V> column(C columnKey) {
    return new Column(columnKey);
  }

  private final class Column extends ViewCachingAbstractMap<R, V> {
    final C columnKey;

    Column(C columnKey) {
      this.columnKey = checkNotNull(columnKey);
    }

    @Override

   *
   * <p>The views returned by the {@code Table} methods {@link Table#column}, {@link
   * Table#columnKeySet}, and {@link Table#columnMap} have iterators that don't support {@code
   * remove()}. Otherwise, all optional operations are supported. Null row keys, columns keys, and
   * values are not supported.
   *
   * <p>Lookups by row key are often faster than lookups by column key, because the data is stored

				newName = field.DBName
			}
		}

		return m.DB.Exec(
			"ALTER TABLE ? RENAME COLUMN ? TO ?",
			m.CurrentTable(stmt), clause.Column{Name: oldName}, clause.Column{Name: newName},
		).Error
	})
}

// MigrateColumn migrate column
func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnType gorm.ColumnType) error {
	if field.IgnoreMigration {

			} else if ref.PrimaryValue != "" {
				conds = append(conds, clause.Eq{
					Column: clause.Column{Table: rel.JoinTable.Table, Name: ref.ForeignKey.DBName},
					Value:  ref.PrimaryValue,
				})
			} else {
				conds = append(conds, clause.Eq{
					Column: clause.Column{Table: rel.JoinTable.Table, Name: ref.ForeignKey.DBName},
					Value:  clause.Column{Table: rel.FieldSchema.Table, Name: ref.PrimaryKey.DBName},
				})
			}
		}