Syntax - Advanced SQL Engine - Teradata Database

{ CREATE | REPLACE } VIEW
  [ database_name. | user_name. ] view_name [ ( column_name [,...] ) ]
  AS { [ temporal_qualifier ] select_statement |
       ( [ temporal_qualifier ] select_statement )
     } [;]

temporal_qualifier

{ valid_time_qualifier [ AND transaction_time_qualifier ] |

  transaction_time_qualifier [ AND valid_time_qualifier ] |

  AS OF date_timestamp_expression
}

valid_time_qualifier

{ CURRENT VALIDTIME |

  VALIDTIME AS OF date_timestamp_expression |

  { [ SEQUENCED | NONSEQUENCED ] VALIDTIME } [ period_expression ]
}

transaction_time_qualifier

{ { CURRENT | SEQUENCED | NONSEQUENCED } TRANSACTIONTIME |

  TRANSACTIONTIME AS OF date_timestamp_expression
}

view_name

Specifies the name of the view.

database_nameuser_name

Specifies the name of the database or user to contain view_name if something other than the current database or user.

column_name

Specifies the name of a view column. If more than one column is specified, list their names in the order in which each column is to be displayed for the view.

CURRENT VALIDTIME

Specifies that select_statement is a current query in the valid-time dimension. The result set is a nontemporal table.

VALIDTIME AS OF date_timestamp_expression

Specifies that select_statement retrieves rows where the period of validity overlaps the specified AS OF expression. The result set is a nontemporal table.

date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.

VALIDTIME SEQUENCED VALIDTIME

Specifies that select_statement is a sequenced query. The result set is a valid-time table that includes an extra column for the overlapped valid-time period. If the list of columns for the view does not provide a name for the extra column, the default name is “VALIDTIME”.

If select_statement is a sequenced query in the valid-time and transaction-time dimensions, and the list of columns for the view provides names for the extra columns, the first extra name is the name of the resulting valid-time column and the second extra name (if it exists) is the name of the resulting transaction-time column.

NONSEQUENCED VALIDTIME

Specifies that select_statement is a nonsequenced query in the valid-time dimension. If period_expression is specified, the nonsequenced query produces a table with valid time; otherwise, the result set is a nontemporal table.

The result set for a valid-time table includes an extra column for the overlapped valid-time period. If the list of columns for the view does not provide a name for the extra column, the default name is “VALIDTIME”.

If select_statement is a nonsequenced query in the valid-time dimension and sequenced in the transaction-time dimension, and the list of columns for the view provides names for the extra columns, the first extra name is the name of the resulting valid-time column and the second extra name (if it exists) is the name of the resulting transaction-time column.

period_expression

Specifies the period of applicability for the sequenced or nonsequenced query.

CURRENT TRANSACTIONTIME

Specifies that select_statement is a current query in the transaction-time dimension. The result set is a nontemporal table.

TRANSACTIONTIME AS OF date_timestamp_expression

Specifies that select_statement retrieves rows whose transaction-time period in the row overlaps the specified AS OF expression. The result set is a nontemporal table.

date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.

SEQUENCED TRANSACTIONTIME

Specifies that select_statement is a sequenced query in the transaction-time dimension. The result set is a table with transaction time.

There can only be one table referenced in select_statement and the table must have transaction time.

NONSEQUENCED TRANSACTIONTIME

Specifies that select_statement is a nonsequenced query in the transaction-time dimension. A nonsequenced query produces a nontemporal table as a result set.

AS OF date_timestamp_expression

Specifies that select_statement retrieves rows whose valid-time and transaction-time periods overlap the specified AS OF expression.

date_timestamp_expression can be a constant, scalar UDF, scalar subquery, or business calendar function that evaluates to a date or timestamp value.

select_statement

Specifies the existing SELECT statement syntax.