Reference Guide > TDV SQL Keywords and Syntax > SELECT
 
SELECT
The SELECT statement selects rows from a table.
Syntax
TDV supports the SELECT statement in various forms:
With a FROM clause and a table
With a FROM clause and a system table named DUAL for queries that do not require a table of actual data
Without a FROM clause
With the syntax SELECT <expression> [,<expression>]; for example:
SELECT 2+2
Remarks
If a network connection is dropped while data is being moved through the TDV Server using SELECT statements, queries are likely to fail. The TDV Serv er cannot reconcile the data when the connection is re-established. You will need to determine when the failure occurred, how much data might have moved, and the best way to resolve the failure.
Overriding SELECT Option Behavior
You can use a configuration parameter to revert the TDV Server default behavior for how SELECTs propagate between the parent and child. The SELECT in TDV will behave in the following manner unless the old SELECT option compatibility mode is enabled:
Joining views that have conflicting select options results in an exception.
Selecting options in joined tables are merged.
Select options in derived tables, scalar subqueries, quantified comparisons will not affect its parent query
To revert the SELECT option behavior
1. Select Administration > Configuration from the main Studio menu.
2. Locate the Enable Old Select Option Compatibility Mode configuration parameter.
3. Set the parameter to True.
Changing the value has no effect until the next server restart.