Skip to content

Latest commit

 

History

History
84 lines (72 loc) · 3.4 KB

AssignAliasFieldsInQuery.md

File metadata and controls

84 lines (72 loc) · 3.4 KB

Assigning aliases to selected fields in a query (AssignAliasFieldsInQuery)

Description

It is recommended to specify optional query constructs, first, to explicitly assign aliases to fields in order to increase the clarity of the query text and the "steadiness" of the code that uses it.
For example, if the algorithm uses a query with a field declared as

CashBox.Currency

when changing the name of the attribute, you will also need to change the code that calls the selection from the query result by the name of the Currency property. If the field is declared as

CashBox.Currency As Currency

then changing the attribute name will only change the request text.

You should be especially careful about automatically assigned aliases for fields - attributes of other fields, such as "... CashBox.Currency.Name...". In the above example, the field will be automatically getting aliased CurrencyName, but not Name.

Be sure to include the AS keyword before the alias of the source field.

The aliases of tables and fields from secondary queries from "UNION" are not checked by the diagnostics.

Examples

    Query = New Query;
Query.Text =
"SELECT
|   Currencies.Ref, // Incorrectly
|   Currencies.Ref AS AliasFieldsRef, // Correctly
|   Currencies.Code Code // Incorrectly
|FROM
|   Catalog.Currencies AS Currencies // Ignored
|
|UNION ALL
|
|SELECT
|   Currencies.Ref, // Ignored
|   Currencies.Ref, // Ignored
|   Currencies.Code // Ignored
|FROM
|   Catalog.Currencies AS Currencies // Ignored
|;
|
|////////////////////////////////////////////////////////////////////////////////
|SELECT
|   Currencies.Ref, // Incorrectly
|   Currencies.Ref AS AliasFieldsRef, // Correctly
|   Currencies.Code Code // Incorrectly
|FROM
|   Catalog.Currencies AS Currencies // Ignored
|
|UNION ALL
|
|SELECT
|   Currencies.Ref, // Ignored
|   Currencies.Ref, // Ignored
|   Currencies.Code // Ignored
|FROM
|   Catalog.Currencies AS Currencies"; // Ignored

Query1 = New Query;
Query1.Text =
"SELECT
|   NestedRequest.Ref AS Ref // Correctly
|FROM
|   (SELECT
|       Currencies.Ref // Incorrectly
|   FROM
|       Catalog.Currencies AS Currencies) AS NestedRequest"; // Ignored

Sources

Source: Making query text